| blob | 6d2b6d1339097e57556c6361e7bf70b4a4365b3d |
1 /*
2 ** 2001 September 15
3 **
4 ** The author disclaims copyright to this source code. In place of
5 ** a legal notice, here is a blessing:
6 **
7 ** May you do good and not evil.
8 ** May you find forgiveness for yourself and forgive others.
9 ** May you share freely, never taking more than you give.
10 **
11 *************************************************************************
12 ** This file contains routines used for analyzing expressions and
13 ** for generating VDBE code that evaluates expressions in SQLite.
14 */
17 /* Forward declarations */
21 /*
22 ** Return the affinity character for a single column of a table.
23 */
27 }
29 /*
30 ** Return the 'affinity' of the expression pExpr if any.
31 **
32 ** If pExpr is a column, a reference to a column via an 'AS' alias,
33 ** or a sub-select with a column as the return value, then the
34 ** affinity of that column is returned. Otherwise, 0x00 is returned,
35 ** indicating no affinity for the expression.
36 **
37 ** i.e. the WHERE clause expressions in the following statements all
38 ** have an affinity:
39 **
40 ** CREATE TABLE t1(a);
41 ** SELECT * FROM t1 WHERE a;
42 ** SELECT a AS b FROM t1 WHERE b;
43 ** SELECT * FROM t1 WHERE (select a from t1);
44 */
53 }
60 }
61 #ifndef SQLITE_OMIT_CAST
65 }
66 #endif
74 );
75 }
79 }
87 }
91 }
93 }
95 /*
96 ** Make a guess at all the possible datatypes of the result that could
97 ** be returned by an expression. Return a bitmask indicating the answer:
98 **
99 ** 0x01 Numeric
100 ** 0x02 Text
101 ** 0x04 Blob
102 **
103 ** If the expression must return NULL, then 0x00 is returned.
104 */
113 }
117 }
120 }
123 }
126 }
131 }
142 }
151 }
154 }
156 }
159 }
163 }
165 /*
166 ** Set the collating sequence for expression pExpr to be the collating
167 ** sequence named by pToken. Return a pointer to a new Expr node that
168 ** implements the COLLATE operator.
169 **
170 ** If a memory allocation error occurs, that fact is recorded in pParse->db
171 ** and the pExpr parameter is returned unchanged.
172 */
178 ){
185 }
186 }
188 }
193 ){
194 Token s;
198 }
200 /*
201 ** Skip over any TK_COLLATE operators.
202 */
207 }
209 }
211 /*
212 ** Skip over any TK_COLLATE operators and/or any unlikely()
213 ** or likelihood() or likely() functions at the root of an
214 ** expression.
215 */
227 }
228 }
230 }
232 /*
233 ** Return the collation sequence for the expression pExpr. If
234 ** there is no defined collating sequence, return NULL.
235 **
236 ** See also: sqlite3ExprNNCollSeq()
237 **
238 ** The sqlite3ExprNNCollSeq() works the same exact that it returns the
239 ** default collation if pExpr has no defined collation.
240 **
241 ** The collating sequence might be determined by a COLLATE operator
242 ** or by the presence of a column with a defined collating sequence.
243 ** COLLATE operators take first precedence. Left operands take
244 ** precedence over right operands.
245 */
255 ){
262 }
264 }
268 }
273 }
278 }
284 /* The Expr.x union is never used at the same time as Expr.pRight */
292 }
293 }
294 }
296 }
299 }
300 }
303 }
305 }
307 /*
308 ** Return the collation sequence for the expression pExpr. If
309 ** there is no defined collating sequence, return a pointer to the
310 ** default collation sequence.
311 **
312 ** See also: sqlite3ExprCollSeq()
313 **
314 ** The sqlite3ExprCollSeq() routine works the same except that it
315 ** returns NULL if there is no defined collation.
316 */
322 }
324 /*
325 ** Return TRUE if the two expressions have equivalent collating sequences.
326 */
331 }
333 /*
334 ** pExpr is an operand of a comparison operator. aff2 is the
335 ** type affinity of the other operand. This routine returns the
336 ** type affinity that should be used for the comparison operator.
337 */
341 /* Both sides of the comparison are columns. If one has numeric
342 ** affinity, use that. Otherwise use no affinity.
343 */
348 }
350 /* One side is a column, the other is not. Use the columns affinity. */
353 }
354 }
356 /*
357 ** pExpr is a comparison operator. Return the type affinity that should
358 ** be applied to both operands prior to doing the comparison.
359 */
373 }
375 }
377 /*
378 ** pExpr is a comparison expression, eg. '=', '<', IN(...) etc.
379 ** idx_affinity is the affinity of an indexed column. Return true
380 ** if the index with affinity idx_affinity may be used to implement
381 ** the comparison in pExpr.
382 */
387 }
390 }
392 }
394 /*
395 ** Return the P5 value that should be used for a binary comparison
396 ** opcode (OP_Eq, OP_Ge etc.) used to compare pExpr1 and pExpr2.
397 */
402 ){
406 }
408 /*
409 ** Return a pointer to the collation sequence that should be used by
410 ** a binary comparison operator comparing pLeft and pRight.
411 **
412 ** If the left hand expression has a collating sequence type, then it is
413 ** used. Otherwise the collation sequence for the right hand expression
414 ** is used, or the default (BINARY) if neither expression has a collating
415 ** type.
416 **
417 ** Argument pRight (but not pLeft) may be a null pointer. In this case,
418 ** it is not considered.
419 */
424 ){
435 }
436 }
438 }
440 /* Expression p is a comparison operator. Return a collation sequence
441 ** appropriate for the comparison operator.
442 **
443 ** This is normally just a wrapper around sqlite3BinaryCompareCollSeq().
444 ** However, if the OP_Commuted flag is set, then the order of the operands
445 ** is reversed in the sqlite3BinaryCompareCollSeq() call so that the
446 ** correct collating sequence is found.
447 */
453 }
454 }
456 /*
457 ** Generate code for a comparison operator.
458 */
468 ){
478 }
484 }
486 /*
487 ** Return true if expression pExpr is a vector, or false otherwise.
488 **
489 ** A vector is defined as any expression that results in two or more
490 ** columns of result. Every TK_VECTOR node is an vector because the
491 ** parser will not generate a TK_VECTOR with fewer than two entries.
492 ** But a TK_SELECT might be either a vector or a scalar. It is only
493 ** considered a vector if it has two or more result columns.
494 */
497 }
499 /*
500 ** If the expression passed as the only argument is of type TK_VECTOR
501 ** return the number of expressions in the vector. Or, if the expression
502 ** is a sub-select, return the number of columns in the sub-select. For
503 ** any other type of expression, return 1.
504 */
516 }
517 }
519 /*
520 ** Return a pointer to a subexpression of pVector that is the i-th
521 ** column of the vector (numbered starting with 0). The caller must
522 ** ensure that i is within range.
523 **
524 ** If pVector is really a scalar (and "scalar" here includes subqueries
525 ** that return a single column!) then return pVector unmodified.
526 **
527 ** pVector retains ownership of the returned subexpression.
528 **
529 ** If the vector is a (SELECT ...) then the expression returned is
530 ** just the expression for the i-th term of the result set, and may
531 ** not be ready for evaluation because the table cursor has not yet
532 ** been positioned.
533 */
544 }
545 }
547 }
549 /*
550 ** Compute and return a new Expr object which when passed to
551 ** sqlite3ExprCode() will generate all necessary code to compute
552 ** the iField-th column of the vector expression pVector.
553 **
554 ** It is ok for pVector to be a scalar (as long as iField==0).
555 ** In that case, this routine works like sqlite3ExprDup().
556 **
557 ** The caller owns the returned Expr object and is responsible for
558 ** ensuring that the returned value eventually gets freed.
559 **
560 ** The caller retains ownership of pVector. If pVector is a TK_SELECT,
561 ** then the returned object will reference pVector and so pVector must remain
562 ** valid for the life of the returned object. If pVector is a TK_VECTOR
563 ** or a scalar expression, then it can be deleted as soon as this routine
564 ** returns.
565 **
566 ** A trick to cause a TK_SELECT pVector to be deleted together with
567 ** the returned Expr object is to attach the pVector to the pRight field
568 ** of the returned TK_SELECT_COLUMN Expr object.
569 */
575 ){
579 /* The TK_SELECT_COLUMN Expr node:
580 **
581 ** pLeft: pVector containing TK_SELECT. Not deleted.
582 ** pRight: not used. But recursively deleted.
583 ** iColumn: Index of a column in pVector
584 ** iTable: 0 or the number of columns on the LHS of an assignment
585 ** pLeft->iTable: First in an array of register holding result, or 0
586 ** if the result is not yet computed.
587 **
588 ** sqlite3ExprDelete() specifically skips the recursive delete of
589 ** pLeft on TK_SELECT_COLUMN nodes. But pRight is followed, so pVector
590 ** can be attached to pRight to cause this node to take ownership of
591 ** pVector. Typically there will be multiple TK_SELECT_COLUMN nodes
592 ** with the same pLeft pointer to the pVector, but only one of them
593 ** will own the pVector.
594 */
601 }
609 /* This must be a vector UPDATE inside a trigger */
612 }
613 }
615 }
617 }
619 /*
620 ** If expression pExpr is of type TK_SELECT, generate code to evaluate
621 ** it. Return the register in which the result is stored (or, if the
622 ** sub-select returns more than one column, the first in an array
623 ** of registers in which the result is stored).
624 **
625 ** If pExpr is not a TK_SELECT expression, return 0.
626 */
629 #ifndef SQLITE_OMIT_SUBQUERY
632 }
633 #endif
635 }
637 /*
638 ** Argument pVector points to a vector expression - either a TK_VECTOR
639 ** or TK_SELECT that returns more than one column. This function returns
640 ** the register number of a register that contains the value of
641 ** element iField of the vector.
642 **
643 ** If pVector is a TK_SELECT expression, then code for it must have
644 ** already been generated using the exprCodeSubselect() routine. In this
645 ** case parameter regSelect should be the first in an array of registers
646 ** containing the results of the sub-select.
647 **
648 ** If pVector is of type TK_VECTOR, then code for the requested field
649 ** is generated. In this case (*pRegFree) may be set to the number of
650 ** a temporary register to be freed by the caller before returning.
651 **
652 ** Before returning, output parameter (*ppExpr) is set to point to the
653 ** Expr object corresponding to element iElem of the vector.
654 */
662 ){
668 }
673 }
678 }
680 }
682 /*
683 ** Expression pExpr is a comparison between two vector values. Compute
684 ** the result of the comparison (1, 0, or NULL) and write that
685 ** result into register dest.
686 **
687 ** The caller must satisfy the following preconditions:
688 **
689 ** if pExpr->op==TK_IS: op==TK_EQ and p5==SQLITE_NULLEQ
690 ** if pExpr->op==TK_ISNOT: op==TK_NE and p5==SQLITE_NULLEQ
691 ** otherwise: op==pExpr->op and p5==0
692 */
698 u8 p5 /* SQLITE_NULLEQ or zero */
699 ){
717 }
722 );
758 }
763 }
766 }
773 }
774 }
779 }
780 }
782 #if SQLITE_MAX_EXPR_DEPTH>0
783 /*
784 ** Check that argument nHeight is less than or equal to the maximum
785 ** expression depth allowed. If it is not, leave an error message in
786 ** pParse.
787 */
794 );
796 }
798 }
800 /* The following three functions, heightOfExpr(), heightOfExprList()
801 ** and heightOfSelect(), are used to determine the maximum height
802 ** of any expression tree referenced by the structure passed as the
803 ** first argument.
804 **
805 ** If this maximum height is greater than the current value pointed
806 ** to by pnHeight, the second parameter, then set *pnHeight to that
807 ** value.
808 */
813 }
814 }
815 }
821 }
822 }
823 }
833 }
834 }
836 /*
837 ** Set the Expr.nHeight variable in the structure passed as an
838 ** argument. An expression with no children, Expr.pList or
839 ** Expr.pSelect member has a height of 1. Any other expression
840 ** has a height equal to the maximum height of any other
841 ** referenced Expr plus one.
842 **
843 ** Also propagate EP_Propagate flags up from Expr.x.pList to Expr.flags,
844 ** if appropriate.
845 */
850 }
856 }
858 }
860 /*
861 ** Set the Expr.nHeight variable using the exprSetHeight() function. If
862 ** the height is greater than the maximum allowed expression depth,
863 ** leave an error in pParse.
864 **
865 ** Also propagate all EP_Propagate flags from the Expr.x.pList into
866 ** Expr.flags.
867 */
872 }
874 /*
875 ** Return the maximum height of any expression tree referenced
876 ** by the select statement passed as an argument.
877 */
882 }
884 /*
885 ** Propagate all EP_Propagate flags from the Expr.x.pList into
886 ** Expr.flags.
887 */
892 }
893 }
894 #define exprSetHeight(y)
897 /*
898 ** Set the error offset for an Expr node, if possible.
899 */
904 }
906 /*
907 ** This routine is the core allocator for Expr nodes.
908 **
909 ** Construct a new expression node and return a pointer to it. Memory
910 ** for this node and for the pToken argument is a single allocation
911 ** obtained from sqlite3DbMalloc(). The calling function
912 ** is responsible for making sure the node eventually gets freed.
913 **
914 ** If dequote is true, then the token (if it exists) is dequoted.
915 ** If dequote is false, no dequoting is performed. The deQuote
916 ** parameter is ignored if pToken is NULL or if the token does not
917 ** appear to be quoted. If the quotes were of the form "..." (double-quotes)
918 ** then the EP_DblQuoted flag is set on the expression node.
919 **
920 ** Special case (tag-20240227-a): If op==TK_INTEGER and pToken points to
921 ** a string that can be translated into a 32-bit integer, then the token is
922 ** not stored in u.zToken. Instead, the integer values is written
923 ** into u.iValue and the EP_IntValue flag is set. No extra storage
924 ** is allocated to hold the integer text and the dequote flag is ignored.
925 ** See also tag-20240227-b.
926 */
932 ){
943 }
944 }
961 }
962 }
963 }
964 #if SQLITE_MAX_EXPR_DEPTH>0
966 #endif
967 }
969 }
971 /*
972 ** Allocate a new expression node from a zero-terminated token that has
973 ** already been dequoted.
974 */
979 ){
980 Token x;
984 }
986 /*
987 ** Attach subtrees pLeft and pRight to the Expr node pRoot.
988 **
989 ** If pRoot==NULL that means that a memory allocation error has occurred.
990 ** In that case, delete the subtrees pLeft and pRight.
991 */
996 Expr *pRight
997 ){
1008 #if SQLITE_MAX_EXPR_DEPTH>0
1012 #endif
1013 }
1017 #if SQLITE_MAX_EXPR_DEPTH>0
1020 }
1021 #endif
1022 }
1023 }
1024 }
1026 /*
1027 ** Allocate an Expr node which joins as many as two subtrees.
1028 **
1029 ** One or both of the subtrees can be NULL. Return a pointer to the new
1030 ** Expr node. Or, if an OOM error occurs, set pParse->db->mallocFailed,
1031 ** free the subtrees and return NULL.
1032 */
1038 ){
1050 }
1052 }
1054 /*
1055 ** Add pSelect to the Expr.x.pSelect field. Or, if pExpr is NULL (due
1056 ** do a memory allocation failure) then delete the pSelect object.
1057 */
1066 }
1067 }
1069 /*
1070 ** Expression list pEList is a list of vector values. This function
1071 ** converts the contents of pEList to a VALUES(...) Select statement
1072 ** returning 1 row for each element of the list. For example, the
1073 ** expression list:
1074 **
1075 ** ( (1,2), (3,4) (5,6) )
1076 **
1077 ** is translated to the equivalent of:
1078 **
1079 ** VALUES(1,2), (3,4), (5,6)
1080 **
1081 ** Each of the vector values in pEList must contain exactly nElem terms.
1082 ** If a list element that is not a vector or does not contain nElem terms,
1083 ** an error message is left in pParse.
1084 **
1085 ** This is used as part of processing IN(...) expressions with a list
1086 ** of vectors on the RHS. e.g. "... IN ((1,2), (3,4), (5,6))".
1087 */
1101 }
1105 );
1107 }
1115 }
1117 }
1118 }
1122 }
1125 }
1127 /*
1128 ** Join two expressions using an AND operator. If either expression is
1129 ** NULL, then just return the other expression.
1130 **
1131 ** If one side or the other of the AND is known to be false, and neither side
1132 ** is part of an ON clause, then instead of returning an AND expression,
1133 ** just return a constant expression with a value of false.
1134 */
1144 && !IN_RENAME_OBJECT
1145 ){
1151 }
1152 }
1153 }
1155 /*
1156 ** Construct a new expression node for a function with multiple
1157 ** arguments.
1158 */
1164 ){
1172 }
1178 ){
1180 }
1187 }
1189 /*
1190 ** Report an error when attempting to use an ORDER BY clause within
1191 ** the arguments of a non-aggregate function.
1192 */
1196 );
1197 }
1199 /*
1200 ** Attach an ORDER BY clause to a function call.
1201 **
1202 ** functionname( arguments ORDER BY sortlist )
1203 ** \_____________________/ \______/
1204 ** pExpr pOrderBy
1205 **
1206 ** The ORDER BY clause is inserted into a new Expr node of type TK_ORDER
1207 ** and added to the Expr.pLeft field of the parent TK_FUNCTION node.
1208 */
1213 ){
1219 }
1224 }
1229 /* Ignore ORDER BY on zero-argument aggregates */
1232 }
1237 }
1243 }
1248 }
1250 /*
1251 ** Check to see if a function is usable according to current access
1252 ** rules:
1253 **
1254 ** SQLITE_FUNC_DIRECT - Only usable from top-level SQL
1255 **
1256 ** SQLITE_FUNC_UNSAFE - Usable if TRUSTED_SCHEMA or from
1257 ** top-level SQL
1258 **
1259 ** If the function is not usable, create an error.
1260 */
1265 ){
1271 ){
1272 /* Functions prohibited in triggers and views if:
1273 ** (1) tagged with SQLITE_DIRECTONLY
1274 ** (2) not tagged with SQLITE_INNOCUOUS (which means it
1275 ** is tagged with SQLITE_FUNC_UNSAFE) and
1276 ** SQLITE_DBCONFIG_TRUSTED_SCHEMA is off (meaning
1277 ** that the schema is possibly tainted).
1278 */
1280 }
1281 }
1282 }
1284 /*
1285 ** Assign a variable number to an expression that encodes a wildcard
1286 ** in the original SQL statement.
1287 **
1288 ** Wildcards consisting of a single "?" are assigned the next sequential
1289 ** variable number.
1290 **
1291 ** Wildcards of the form "?nnn" are assigned the number "nnn". We make
1292 ** sure "nnn" is not too big to avoid a denial of service attack when
1293 ** the SQL statement comes from an external source.
1294 **
1295 ** Wildcards of the form ":aaa", "@aaa", or "$aaa" are assigned the same number
1296 ** as the previous instance of the same wildcard. Or if this is the first
1297 ** instance of the wildcard, the next sequential variable number is
1298 ** assigned.
1299 */
1303 ynVar x;
1312 /* Wildcard of the form "?". Assign the next variable number */
1318 /* Wildcard of the form "?nnn". Convert "nnn" to an integer and
1319 ** use it as the variable number */
1320 i64 i;
1327 }
1337 }
1344 }
1346 /* Wildcards like ":aaa", "$aaa" or "@aaa". Reuse the same variable
1347 ** number as the prior appearance of the same name, or if the name
1348 ** has never appeared before, reuse the same variable number
1349 */
1354 }
1355 }
1358 }
1359 }
1364 }
1365 }
1367 /*
1368 ** Recursively delete an expression tree.
1369 */
1373 exprDeleteRestart:
1378 #ifdef SQLITE_DEBUG
1384 }
1385 #endif
1387 /* The Expr.x union is never used at the same time as Expr.pRight */
1397 #ifndef SQLITE_OMIT_WINDOWFUNC
1400 }
1401 #endif
1402 }
1407 ){
1408 /* Avoid unnecessary recursion on unary operators */
1414 }
1415 }
1416 }
1419 }
1420 }
1423 }
1426 }
1428 /*
1429 ** Clear both elements of an OnOrUsing object
1430 */
1433 /* Nothing to clear */
1438 }
1439 }
1441 /*
1442 ** Arrange to cause pExpr to be deleted when the pParse is deleted.
1443 ** This is similar to sqlite3ExprDelete() except that the delete is
1444 ** deferred until the pParse is deleted.
1445 **
1446 ** The pExpr might be deleted immediately on an OOM error.
1447 **
1448 ** Return 0 if the delete was successfully deferred. Return non-zero
1449 ** if the delete happened immediately because of an OOM.
1450 */
1453 }
1455 /* Invoke sqlite3RenameExprUnmap() and sqlite3ExprDelete() on the
1456 ** expression.
1457 */
1462 }
1464 }
1465 }
1467 /*
1468 ** Return the number of bytes allocated for the expression structure
1469 ** passed as the first argument. This is always one of EXPR_FULLSIZE,
1470 ** EXPR_REDUCEDSIZE or EXPR_TOKENONLYSIZE.
1471 */
1476 }
1478 /*
1479 ** The dupedExpr*Size() routines each return the number of bytes required
1480 ** to store a copy of an expression or expression tree. They differ in
1481 ** how much of the tree is measured.
1482 **
1483 ** dupedExprStructSize() Size of only the Expr structure
1484 ** dupedExprNodeSize() Size of Expr + space for token
1485 ** dupedExprSize() Expr + token + subtree components
1486 **
1487 ***************************************************************************
1488 **
1489 ** The dupedExprStructSize() function returns two values OR-ed together:
1490 ** (1) the space required for a copy of the Expr structure only and
1491 ** (2) the EP_xxx flags that indicate what the structure size should be.
1492 ** The return values is always one of:
1493 **
1494 ** EXPR_FULLSIZE
1495 ** EXPR_REDUCEDSIZE | EP_Reduced
1496 ** EXPR_TOKENONLYSIZE | EP_TokenOnly
1497 **
1498 ** The size of the structure can be found by masking the return value
1499 ** of this routine with 0xfff. The flags can be found by masking the
1500 ** return value with EP_Reduced|EP_TokenOnly.
1501 **
1502 ** Note that with flags==EXPRDUP_REDUCE, this routines works on full-size
1503 ** (unreduced) Expr objects as they or originally constructed by the parser.
1504 ** During expression analysis, extra information is computed and moved into
1505 ** later parts of the Expr object and that extra information might get chopped
1506 ** off if the expression is reduced. Note also that it does not work to
1507 ** make an EXPRDUP_REDUCE copy of a reduced expression. It is only legal
1508 ** to reduce a pristine expression tree from the parser. The implementation
1509 ** of dupedExprStructSize() contain multiple assert() statements that attempt
1510 ** to enforce this constraint.
1511 */
1528 }
1529 }
1531 }
1533 /*
1534 ** This function returns the space in bytes required to store the copy
1535 ** of the Expr structure and a copy of the Expr.u.zToken string (if that
1536 ** string is defined.)
1537 */
1542 }
1544 }
1546 /*
1547 ** Return the number of bytes required to create a duplicate of the
1548 ** expression passed as the first argument.
1549 **
1550 ** The value returned includes space to create a copy of the Expr struct
1551 ** itself and the buffer referred to by Expr.u.zToken, if any.
1552 **
1553 ** The return value includes space to duplicate all Expr nodes in the
1554 ** tree formed by Expr.pLeft and Expr.pRight, but not any other
1555 ** substructure such as Expr.x.pList, Expr.x.pSelect, and Expr.y.pWin.
1556 */
1565 }
1567 /*
1568 ** An EdupBuf is a memory allocation used to stored multiple Expr objects
1569 ** together with their Expr.zToken content. This is used to help implement
1570 ** compression while doing sqlite3ExprDup(). The top-level Expr does the
1571 ** allocation for itself and many of its decendents, then passes an instance
1572 ** of the structure down into exprDup() so that they decendents can have
1573 ** access to that memory.
1574 */
1578 #ifdef SQLITE_DEBUG
1580 #endif
1581 };
1583 /*
1584 ** This function is similar to sqlite3ExprDup(), except that if pEdupBuf
1585 ** is not NULL then it points to memory that can be used to store a copy
1586 ** of the input Expr p together with its p->u.zToken (if any). pEdupBuf
1587 ** is updated with the new buffer tail prior to returning.
1588 */
1594 ){
1605 /* Figure out where to write the new Expr structure. */
1608 #ifdef SQLITE_DEBUG
1610 #endif
1624 }
1627 #ifdef SQLITE_DEBUG
1629 #endif
1632 }
1637 /* Set nNewSize to the size allocated for the structure pointed to
1638 ** by pNew. This is either EXPR_FULLSIZE, EXPR_REDUCEDSIZE or
1639 ** EXPR_TOKENONLYSIZE. nToken is set to the number of bytes consumed
1640 ** by the copy of the p->u.zToken string (if any).
1641 */
1649 }
1650 }
1662 }
1664 }
1666 /* Set the EP_Reduced, EP_TokenOnly, and EP_Static flags appropriately. */
1673 }
1675 /* Copy the p->u.zToken string, if any. */
1681 }
1686 /* Fill in the pNew->x.pSelect or pNew->x.pList member. */
1692 }
1694 #ifndef SQLITE_OMIT_WINDOWFUNC
1698 }
1701 /* Fill in pNew->pLeft and pNew->pRight. */
1711 }
1722 }
1724 }
1725 }
1726 }
1730 }
1732 /*
1733 ** Create and return a deep copy of the object passed as the second
1734 ** argument. If an OOM condition is encountered, NULL is returned
1735 ** and the db->mallocFailed flag set.
1736 */
1737 #ifndef SQLITE_OMIT_CTE
1751 }
1752 }
1753 }
1755 }
1756 #else
1757 # define sqlite3WithDup(x,y) 0
1758 #endif
1760 #ifndef SQLITE_OMIT_WINDOWFUNC
1761 /*
1762 ** The gatherSelectWindows() procedure and its helper routine
1763 ** gatherSelectWindowsCallback() are used to scan all the expressions
1764 ** an a newly duplicated SELECT statement and gather all of the Window
1765 ** objects found there, assembling them onto the linked list at Select->pWin.
1766 */
1775 }
1777 }
1780 }
1782 Walker w;
1789 }
1790 #endif
1793 /*
1794 ** The following group of routines make deep copies of expressions,
1795 ** expression lists, ID lists, and select statements. The copies can
1796 ** be deleted (by being passed to their respective ...Delete() routines)
1797 ** without effecting the originals.
1798 **
1799 ** The expression list, ID, and source lists return by sqlite3ExprListDup(),
1800 ** sqlite3IdListDup(), and sqlite3SrcListDup() can not be further expanded
1801 ** by subsequent calls to sqlite*ListAppend() routines.
1802 **
1803 ** Any tables that the SrcList might point to are not duplicated.
1804 **
1805 ** The flags parameter contains a combination of the EXPRDUP_XXX flags.
1806 ** If the EXPRDUP_REDUCE flag is set, then the structure returned is a
1807 ** truncated version of the usual Expr structure that will be stored as
1808 ** part of the in-memory representation of the database schema.
1809 */
1813 }
1836 ){
1846 }
1848 }
1849 }
1854 }
1856 }
1858 /*
1859 ** If cursors, triggers, views and subqueries are all omitted from
1860 ** the build, then none of the following routines, except for
1861 ** sqlite3SelectDup(), can be called. sqlite3SelectDup() is sometimes
1862 ** called with a NULL argument.
1863 */
1864 #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER) \
1865 || !defined(SQLITE_OMIT_SUBQUERY)
1896 }
1900 }
1904 }
1911 }
1913 }
1915 }
1931 }
1933 }
1961 #ifndef SQLITE_OMIT_WINDOWFUNC
1965 #endif
1968 /* Any prior OOM might have left the Select object incomplete.
1969 ** Delete the whole thing rather than allow an incomplete Select
1970 ** to be used by the code generator. */
1974 }
1978 }
1981 }
1982 #else
1986 }
1987 #endif
1990 /*
1991 ** Add a new element to the end of an expression list. If pList is
1992 ** initially NULL, then create a new expression list.
1993 **
1994 ** The pList argument must be either NULL or a pointer to an ExprList
1995 ** obtained from a prior call to sqlite3ExprListAppend().
1996 **
1997 ** If a memory allocation error occurs, the entire list is freed and
1998 ** NULL is returned. If non-NULL is returned, then it is guaranteed
1999 ** that the new entry was successfully appended.
2000 */
2005 ){
2013 }
2020 }
2025 ){
2037 }
2042 }
2047 ){
2051 }
2054 }
2059 }
2061 /*
2062 ** pColumns and pExpr form a vector assignment which is part of the SET
2063 ** clause of an UPDATE statement. Like this:
2064 **
2065 ** (a,b,c) = (expr1,expr2,expr3)
2066 ** Or: (a,b,c) = (SELECT x,y,z FROM ....)
2067 **
2068 ** For each term of the vector assignment, append new entries to the
2069 ** expression list pList. In the case of a subquery on the RHS, append
2070 ** TK_SELECT_COLUMN expressions.
2071 */
2077 ){
2082 /* pColumns can only be NULL due to an OOM but an OOM will cause an
2083 ** exit prior to this routine being invoked */
2087 /* If the RHS is a vector, then we can immediately check to see that
2088 ** the size of the RHS and LHS match. But if the RHS is a SELECT,
2089 ** wildcards ("*") in the result set of the SELECT must be expanded before
2090 ** we can do the size check, so defer the size check until code generation.
2091 */
2096 }
2107 }
2108 }
2115 /* Store the SELECT statement in pRight so it will be deleted when
2116 ** sqlite3ExprListDelete() is called */
2120 /* Remember the size of the LHS in iTable so that we can check that
2121 ** the RHS and LHS sizes match during code generation. */
2123 }
2125 vector_append_error:
2129 }
2131 /*
2132 ** Set the sort order for the last element on the given ExprList.
2133 */
2143 );
2147 );
2153 }
2160 }
2161 }
2162 }
2164 /*
2165 ** Set the ExprList.a[].zEName element of the most recently added item
2166 ** on the expression list.
2167 **
2168 ** pList might be NULL following an OOM error. But pName should never be
2169 ** NULL. If a memory allocation fails, the pParse->db->mallocFailed flag
2170 ** is set.
2171 */
2177 ){
2188 /* If dequote==0, then pName->z does not point to part of a DDL
2189 ** statement handled by the parser. And so no token need be added
2190 ** to the token-map. */
2194 }
2195 }
2196 }
2197 }
2199 /*
2200 ** Set the ExprList.a[].zSpan element of the most recently added item
2201 ** on the expression list.
2202 **
2203 ** pList might be NULL following an OOM error. But pSpan should never be
2204 ** NULL. If a memory allocation fails, the pParse->db->mallocFailed flag
2205 ** is set.
2206 */
2212 ){
2221 }
2222 }
2223 }
2225 /*
2226 ** If the expression list pEList contains more than iLimit elements,
2227 ** leave an error message in pParse.
2228 */
2233 ){
2239 }
2240 }
2242 /*
2243 ** Delete an entire expression list.
2244 */
2253 pItem++;
2256 }
2259 }
2262 }
2264 /*
2265 ** Return the bitwise-OR of all Expr.flags fields in the given
2266 ** ExprList.
2267 */
2276 }
2278 }
2280 /*
2281 ** This is a SELECT-node callback for the expression walker that
2282 ** always "fails". By "fail" in this case, we mean set
2283 ** pWalker->eCode to zero and abort.
2284 **
2285 ** This callback is used by multiple expression walkers.
2286 */
2291 }
2293 /*
2294 ** Check the input string to see if it is "true" or "false" (in any case).
2295 **
2296 ** If the string is.... Return
2297 ** "true" EP_IsTrue
2298 ** "false" EP_IsFalse
2299 ** anything else 0
2300 */
2305 }
2308 /*
2309 ** If the input expression is an ID with the name "true" or "false"
2310 ** then convert it into an TK_TRUEFALSE term. Return non-zero if
2311 ** the conversion happened, and zero if the expression is unaltered.
2312 */
2314 u32 v;
2318 ){
2322 }
2324 }
2326 /*
2327 ** The argument must be a TK_TRUEFALSE Expr node. Return 1 if it is TRUE
2328 ** and 0 if it is FALSE.
2329 */
2337 }
2339 /*
2340 ** If pExpr is an AND or OR expression, try to simplify it by eliminating
2341 ** terms that are always true or false. Return the simplified expression.
2342 ** Or return the original expression if no simplification is possible.
2343 **
2344 ** Examples:
2345 **
2346 ** (x<10) AND true => (x<10)
2347 ** (x<10) AND false => false
2348 ** (x<10) AND (y=22 OR false) => (x<10) AND (y=22)
2349 ** (x<10) AND (y=22 OR true) => (x<10)
2350 ** (y=22) OR true => true
2351 */
2361 }
2362 }
2364 }
2366 /*
2367 ** pExpr is a TK_FUNCTION node. Try to determine whether or not the
2368 ** function is a constant function. A function is constant if all of
2369 ** the following are true:
2370 **
2371 ** (1) It is a scalar function (not an aggregate or window function)
2372 ** (2) It has either the SQLITE_FUNC_CONSTANT or SQLITE_FUNC_SLOCHNG
2373 ** property.
2374 ** (3) All of its arguments are constants
2375 **
2376 ** This routine sets pWalker->eCode to 0 if pExpr is not a constant.
2377 ** It makes no changes to pWalker->eCode if pExpr is constant. In
2378 ** every case, it returns WRC_Abort.
2379 **
2380 ** Called as a service subroutine from exprNodeIsConstant().
2381 */
2384 Expr *pExpr
2385 ){
2394 ){;
2400 }
2407 ){
2410 }
2412 }
2415 /*
2416 ** These routines are Walker callbacks used to check expressions to
2417 ** see if they are "constant" for some definition of constant. The
2418 ** Walker.eCode value determines the type of "constant" we are looking
2419 ** for.
2420 **
2421 ** These callback routines are used to implement the following:
2422 **
2423 ** sqlite3ExprIsConstant() pWalker->eCode==1
2424 ** sqlite3ExprIsConstantNotJoin() pWalker->eCode==2
2425 ** sqlite3ExprIsTableConstant() pWalker->eCode==3
2426 ** sqlite3ExprIsConstantOrFunction() pWalker->eCode==4 or 5
2427 **
2428 ** In all cases, the callbacks set Walker.eCode=0 and abort if the expression
2429 ** is found to not be a constant.
2430 **
2431 ** The sqlite3ExprIsConstantOrFunction() is used for evaluating DEFAULT
2432 ** expressions in a CREATE TABLE statement. The Walker.eCode value is 5
2433 ** when parsing an existing schema out of the sqlite_schema table and 4
2434 ** when processing a new CREATE TABLE statement. A bound parameter raises
2435 ** an error for new statements, but is silently converted
2436 ** to NULL for existing schemas. This allows sqlite_schema tables that
2437 ** contain a bound parameter because they were generated by older versions
2438 ** of SQLite to be parsed by newer versions of SQLite without raising a
2439 ** malformed schema error.
2440 */
2444 /* If pWalker->eCode is 2 then any term of the expression that comes from
2445 ** the ON or USING clauses of an outer join disqualifies the expression
2446 ** from being considered constant. */
2450 }
2453 /* Consider functions to be constant if all their arguments are constant
2454 ** and either pWalker->eCode==4 or 5 or the function has the
2455 ** SQLITE_FUNC_CONST flag. */
2459 ){
2467 }
2469 /* Convert "true" or "false" in a DEFAULT clause into the
2470 ** appropriate TK_TRUEFALSE operator */
2473 }
2474 /* no break */ deliberate_fall_through
2484 }
2487 }
2488 /* no break */ deliberate_fall_through
2501 /* Silently convert bound parameters that appear inside of CREATE
2502 ** statements into a NULL when parsing the CREATE statement text out
2503 ** of the sqlite_schema table */
2506 /* A bound parameter in a CREATE statement that originates from
2507 ** sqlite3_prepare() causes an error */
2510 }
2511 /* no break */ deliberate_fall_through
2516 }
2517 }
2519 Walker w;
2524 #ifdef SQLITE_DEBUG
2526 #endif
2529 }
2531 /*
2532 ** Walk an expression tree. Return non-zero if the expression is constant
2533 ** and 0 if it involves variables or function calls.
2534 **
2535 ** For the purposes of this function, a double-quoted string (ex: "abc")
2536 ** is considered a variable but a single-quoted string (ex: 'abc') is
2537 ** a constant.
2538 **
2539 ** The pParse parameter may be NULL. But if it is NULL, there is no way
2540 ** to determine if function calls are constant or not, and hence all
2541 ** function calls will be considered to be non-constant. If pParse is
2542 ** not NULL, then a function call might be constant, depending on the
2543 ** function and on its parameters.
2544 */
2547 }
2549 /*
2550 ** Walk an expression tree. Return non-zero if
2551 **
2552 ** (1) the expression is constant, and
2553 ** (2) the expression does originate in the ON or USING clause
2554 ** of a LEFT JOIN, and
2555 ** (3) the expression does not contain any EP_FixedCol TK_COLUMN
2556 ** operands created by the constant propagation optimization.
2557 **
2558 ** When this routine returns true, it indicates that the expression
2559 ** can be added to the pParse->pConstExpr list and evaluated once when
2560 ** the prepared statement starts up. See sqlite3ExprCodeRunJustOnce().
2561 */
2564 }
2566 /*
2567 ** This routine examines sub-SELECT statements as an expression is being
2568 ** walked as part of sqlite3ExprIsTableConstant(). Sub-SELECTs are considered
2569 ** constant as long as they are uncorrelated - meaning that they do not
2570 ** contain any terms from outer contexts.
2571 */
2578 }
2580 }
2582 /*
2583 ** Walk an expression tree. Return non-zero if the expression is constant
2584 ** for any single row of the table with cursor iCur. In other words, the
2585 ** expression must not refer to any non-deterministic function nor any
2586 ** table other than iCur.
2587 **
2588 ** Consider uncorrelated subqueries to be constants if the bAllowSubq
2589 ** parameter is true.
2590 */
2592 Walker w;
2600 #ifdef SQLITE_DEBUG
2602 #endif
2603 }
2607 }
2609 /*
2610 ** Check pExpr to see if it is an constraint on the single data source
2611 ** pSrc = &pSrcList->a[iSrc]. In other words, check to see if pExpr
2612 ** constrains pSrc but does not depend on any other tables or data
2613 ** sources anywhere else in the query. Return true (non-zero) if pExpr
2614 ** is a constraint on pSrc only.
2615 **
2616 ** This is an optimization. False negatives will perhaps cause slower
2617 ** queries, but false positives will yield incorrect answers. So when in
2618 ** doubt, return 0.
2619 **
2620 ** To be an single-source constraint, the following must be true:
2621 **
2622 ** (1) pExpr cannot refer to any table other than pSrc->iCursor.
2623 **
2624 ** (2a) pExpr cannot use subqueries unless the bAllowSubq parameter is
2625 ** true and the subquery is non-correlated
2626 **
2627 ** (2b) pExpr cannot use non-deterministic functions.
2628 **
2629 ** (3) pSrc cannot be part of the left operand for a RIGHT JOIN.
2630 ** (Is there some way to relax this constraint?)
2631 **
2632 ** (4) If pSrc is the right operand of a LEFT JOIN, then...
2633 ** (4a) pExpr must come from an ON clause..
2634 ** (4b) and specifically the ON clause associated with the LEFT JOIN.
2635 **
2636 ** (5) If pSrc is not the right operand of a LEFT JOIN or the left
2637 ** operand of a RIGHT JOIN, then pExpr must be from the WHERE
2638 ** clause, not an ON clause.
2639 **
2640 ** (6) Either:
2641 **
2642 ** (6a) pExpr does not originate in an ON or USING clause, or
2643 **
2644 ** (6b) The ON or USING clause from which pExpr is derived is
2645 ** not to the left of a RIGHT JOIN (or FULL JOIN).
2646 **
2647 ** Without this restriction, accepting pExpr as a single-table
2648 ** constraint might move the the ON/USING filter expression
2649 ** from the left side of a RIGHT JOIN over to the right side,
2650 ** which leads to incorrect answers. See also restriction (9)
2651 ** on push-down.
2652 */
2658 ){
2662 }
2668 }
2671 ){
2677 }
2679 }
2680 }
2681 }
2682 /* Rules (1), (2a), and (2b) handled by the following: */
2684 }
2687 /*
2688 ** sqlite3WalkExpr() callback used by sqlite3ExprIsConstantOrGroupBy().
2689 */
2694 /* Check if pExpr is identical to any GROUP BY term. If so, consider
2695 ** it constant. */
2702 }
2703 }
2704 }
2706 /* Check if pExpr is a sub-select. If so, consider it variable. */
2710 }
2713 }
2715 /*
2716 ** Walk the expression tree passed as the first argument. Return non-zero
2717 ** if the expression consists entirely of constants or copies of terms
2718 ** in pGroupBy that sort with the BINARY collation sequence.
2719 **
2720 ** This routine is used to determine if a term of the HAVING clause can
2721 ** be promoted into the WHERE clause. In order for such a promotion to work,
2722 ** the value of the HAVING clause term must be the same for all members of
2723 ** a "group". The requirement that the GROUP BY term must be BINARY
2724 ** assumes that no other collating sequence will have a finer-grained
2725 ** grouping than binary. In other words (A=B COLLATE binary) implies
2726 ** A=B in every other collating sequence. The requirement that the
2727 ** GROUP BY be BINARY is stricter than necessary. It would also work
2728 ** to promote HAVING clauses that use the same alternative collating
2729 ** sequence as the GROUP BY term, but that is much harder to check,
2730 ** alternative collating sequences are uncommon, and this is only an
2731 ** optimization, so we take the easy way out and simply require the
2732 ** GROUP BY to use the BINARY collating sequence.
2733 */
2735 Walker w;
2743 }
2745 /*
2746 ** Walk an expression tree for the DEFAULT field of a column definition
2747 ** in a CREATE TABLE statement. Return non-zero if the expression is
2748 ** acceptable for use as a DEFAULT. That is to say, return non-zero if
2749 ** the expression is constant or a function call with constant arguments.
2750 ** Return and 0 if there are any variables.
2751 **
2752 ** isInit is true when parsing from sqlite_schema. isInit is false when
2753 ** processing a new CREATE TABLE statement. When isInit is true, parameters
2754 ** (such as ? or $abc) in the expression are converted into NULL. When
2755 ** isInit is false, parameters raise an error. Parameters should not be
2756 ** allowed in a CREATE TABLE statement, but some legacy versions of SQLite
2757 ** allowed it, so we need to support it when reading sqlite_schema for
2758 ** backwards compatibility.
2759 **
2760 ** If isInit is true, set EP_FromDDL on every TK_FUNCTION node.
2761 **
2762 ** For the purposes of this function, a double-quoted string (ex: "abc")
2763 ** is considered a variable but a single-quoted string (ex: 'abc') is
2764 ** a constant.
2765 */
2769 }
2771 #ifdef SQLITE_ENABLE_CURSOR_HINTS
2772 /*
2773 ** Walk an expression tree. Return 1 if the expression contains a
2774 ** subquery of some kind. Return 0 if there are no subqueries.
2775 */
2777 Walker w;
2781 #ifdef SQLITE_DEBUG
2783 #endif
2786 }
2787 #endif
2789 /*
2790 ** If the expression p codes a constant integer that is small enough
2791 ** to fit in a 32-bit integer, return 1 and put the value of the integer
2792 ** in *pValue. If the expression is not an integer or if it is too big
2793 ** to fit in a signed 32-bit integer, return 0 and leave *pValue unchanged.
2794 **
2795 ** If the pParse pointer is provided, then allow the expression p to be
2796 ** a parameter (TK_VARIABLE) that is bound to an integer.
2797 ** But if pParse is NULL, then p must be a pure integer literal.
2798 */
2803 /* If an expression is an integer literal that fits in a signed 32-bit
2804 ** integer, then the EP_IntValue flag will have already been set */
2811 }
2816 }
2823 }
2825 }
2833 SQLITE_AFF_BLOB);
2840 }
2841 }
2843 }
2845 }
2847 }
2849 }
2851 /*
2852 ** Return FALSE if there is no chance that the expression can be NULL.
2853 **
2854 ** If the expression might be NULL or if the expression is too complex
2855 ** to tell return TRUE.
2856 **
2857 ** This routine is used as an optimization, to skip OP_IsNull opcodes
2858 ** when we know that a value cannot be NULL. Hence, a false positive
2859 ** (returning TRUE when in fact the expression can never be NULL) might
2860 ** be a small performance hit but is otherwise harmless. On the other
2861 ** hand, a false negative (returning FALSE when the result could be NULL)
2862 ** will likely result in an incorrect answer. So when in doubt, return
2863 ** TRUE.
2864 */
2866 u8 op;
2871 }
2884 #ifdef SQLITE_ALLOW_ROWID_IN_VIEW
2886 #endif
2893 }
2894 }
2896 /*
2897 ** Return TRUE if the given expression is a constant which would be
2898 ** unchanged by OP_Affinity with the affinity given in the second
2899 ** argument.
2900 **
2901 ** This routine is used to determine if the OP_Affinity operation
2902 ** can be omitted. When in doubt return FALSE. A false negative
2903 ** is harmless. A false positive, however, can result in the wrong
2904 ** answer.
2905 */
2907 u8 op;
2913 }
2919 }
2922 }
2925 }
2928 }
2932 }
2935 }
2936 }
2937 }
2939 /*
2940 ** Return TRUE if the given string is a row-id column name.
2941 */
2947 }
2949 /*
2950 ** Return a pointer to a buffer containing a usable rowid alias for table
2951 ** pTab. An alias is usable if there is not an explicit user-defined column
2952 ** of the same name.
2953 */
2962 }
2965 }
2966 }
2968 }
2970 /*
2971 ** pX is the RHS of an IN operator. If pX is a SELECT statement
2972 ** that can be simplified to a direct table access, then return
2973 ** a pointer to the SELECT statement. If pX is not a SELECT statement,
2974 ** or if the SELECT statement needs to be materialized into a transient
2975 ** table, then return NULL.
2976 */
2977 #ifndef SQLITE_OMIT_SUBQUERY
2992 }
3006 /* All SELECT results must be columns. */
3011 }
3013 }
3016 #ifndef SQLITE_OMIT_SUBQUERY
3017 /*
3018 ** Generate code that checks the left-most column of index table iCur to see if
3019 ** it contains any NULL entries. Cause the register at regHasNull to be set
3020 ** to a non-NULL value if iCur contains no NULLs. Cause register regHasNull
3021 ** to be set to NULL if iCur contains one or more NULL values.
3022 */
3031 }
3032 #endif
3035 #ifndef SQLITE_OMIT_SUBQUERY
3036 /*
3037 ** The argument is an IN operator with a list (not a subquery) on the
3038 ** right-hand side. Return TRUE if that list is constant.
3039 */
3049 }
3050 #endif
3052 /*
3053 ** This function is used by the implementation of the IN (...) operator.
3054 ** The pX parameter is the expression on the RHS of the IN operator, which
3055 ** might be either a list of expressions or a subquery.
3056 **
3057 ** The job of this routine is to find or create a b-tree object that can
3058 ** be used either to test for membership in the RHS set or to iterate through
3059 ** all members of the RHS set, skipping duplicates.
3060 **
3061 ** A cursor is opened on the b-tree object that is the RHS of the IN operator
3062 ** and the *piTab parameter is set to the index of that cursor.
3063 **
3064 ** The returned value of this function indicates the b-tree type, as follows:
3065 **
3066 ** IN_INDEX_ROWID - The cursor was opened on a database table.
3067 ** IN_INDEX_INDEX_ASC - The cursor was opened on an ascending index.
3068 ** IN_INDEX_INDEX_DESC - The cursor was opened on a descending index.
3069 ** IN_INDEX_EPH - The cursor was opened on a specially created and
3070 ** populated ephemeral table.
3071 ** IN_INDEX_NOOP - No cursor was allocated. The IN operator must be
3072 ** implemented as a sequence of comparisons.
3073 **
3074 ** An existing b-tree might be used if the RHS expression pX is a simple
3075 ** subquery such as:
3076 **
3077 ** SELECT <column1>, <column2>... FROM <table>
3078 **
3079 ** If the RHS of the IN operator is a list or a more complex subquery, then
3080 ** an ephemeral table might need to be generated from the RHS and then
3081 ** pX->iTable made to point to the ephemeral table instead of an
3082 ** existing table. In this case, the creation and initialization of the
3083 ** ephemeral table might be put inside of a subroutine, the EP_Subrtn flag
3084 ** will be set on pX and the pX->y.sub fields will be set to show where
3085 ** the subroutine is coded.
3086 **
3087 ** The inFlags parameter must contain, at a minimum, one of the bits
3088 ** IN_INDEX_MEMBERSHIP or IN_INDEX_LOOP but not both. If inFlags contains
3089 ** IN_INDEX_MEMBERSHIP, then the generated table will be used for a fast
3090 ** membership test. When the IN_INDEX_LOOP bit is set, the IN index will
3091 ** be used to loop over all values of the RHS of the IN operator.
3092 **
3093 ** When IN_INDEX_LOOP is used (and the b-tree will be used to iterate
3094 ** through the set members) then the b-tree must not contain duplicates.
3095 ** An ephemeral table will be created unless the selected columns are guaranteed
3096 ** to be unique - either because it is an INTEGER PRIMARY KEY or due to
3097 ** a UNIQUE constraint or index.
3098 **
3099 ** When IN_INDEX_MEMBERSHIP is used (and the b-tree will be used
3100 ** for fast set membership tests) then an ephemeral table must
3101 ** be used unless <columns> is a single INTEGER PRIMARY KEY column or an
3102 ** index can be found with the specified <columns> as its left-most.
3103 **
3104 ** If the IN_INDEX_NOOP_OK and IN_INDEX_MEMBERSHIP are both set and
3105 ** if the RHS of the IN operator is a list (not a subquery) then this
3106 ** routine might decide that creating an ephemeral b-tree for membership
3107 ** testing is too expensive and return IN_INDEX_NOOP. In that case, the
3108 ** calling routine should implement the IN operator using a sequence
3109 ** of Eq or Ne comparison operations.
3110 **
3111 ** When the b-tree is being used for membership tests, the calling function
3112 ** might need to know whether or not the RHS side of the IN operator
3113 ** contains a NULL. If prRhsHasNull is not a NULL pointer and
3114 ** if there is any chance that the (...) might contain a NULL value at
3115 ** runtime, then a register is allocated and the register number written
3116 ** to *prRhsHasNull. If there is no chance that the (...) contains a
3117 ** NULL value, then *prRhsHasNull is left unchanged.
3118 **
3119 ** If a register is allocated and its location stored in *prRhsHasNull, then
3120 ** the value in that register will be NULL if the b-tree contains one or more
3121 ** NULL values, and it will be some non-NULL value if the b-tree contains no
3122 ** NULL values.
3123 **
3124 ** If the aiMap parameter is not NULL, it must point to an array containing
3125 ** one element for each column returned by the SELECT statement on the RHS
3126 ** of the IN(...) operator. The i'th entry of the array is populated with the
3127 ** offset of the index column that matches the i'th column returned by the
3128 ** SELECT. For example, if the expression and selected index are:
3129 **
3130 ** (?,?,?) IN (SELECT a, b, c FROM t1)
3131 ** CREATE INDEX i1 ON t1(b, c, a);
3132 **
3133 ** then aiMap[] is populated with {2, 0, 1}.
3134 */
3135 #ifndef SQLITE_OMIT_SUBQUERY
3143 ){
3154 /* If the RHS of this IN(...) operator is a SELECT, and if it matters
3155 ** whether or not the SELECT result contains NULL values, check whether
3156 ** or not NULL is actually possible (it may not be, for example, due
3157 ** to NOT NULL constraints in the schema). If no NULL values are possible,
3158 ** set prRhsHasNull to 0 before continuing. */
3164 }
3167 }
3168 }
3170 /* Check to see if an existing table or index can be used to
3171 ** satisfy the query. This is preferable to generating a new
3172 ** ephemeral table. */
3185 /* Code an OP_Transaction and OP_TableLock for <table>. */
3193 /* The "x IN (SELECT rowid FROM table)" case */
3207 /* Check that the affinity that will be used to perform each
3208 ** comparison is the same as the affinity of each column in table
3209 ** on the RHS of the IN operator. If it not, it is not possible to
3210 ** use any index of the RHS table. */
3222 /* sqlite3CompareAffinity() only returns TEXT if one side or the
3223 ** other has no affinity and the other side is TEXT. Hence,
3224 ** the only way for cmpaff to be TEXT is for idxaff to be TEXT
3225 ** and for the term on the LHS of the IN to have no affinity. */
3230 }
3231 }
3234 /* Search for an existing index that will work for this IN operator */
3240 /* Maximum nColumn is BMS-2, not BMS-1, so that we can compute
3241 ** BITMASK(nExpr) without overflowing */
3248 ){
3250 }
3251 }
3265 }
3267 }
3273 }
3277 /* If we reach this point, that means the index pIdx is usable */
3288 #ifdef SQLITE_ENABLE_COLUMN_USED_MASK
3292 #endif
3296 }
3297 }
3299 }
3305 /* If no preexisting index is available for the IN clause
3306 ** and IN_INDEX_NOOP is an allowed reply
3307 ** and the RHS of the IN operator is a list, not a subquery
3308 ** and the RHS is not constant or has two or fewer terms,
3309 ** then it is not worth creating an ephemeral table to evaluate
3310 ** the IN operator so return IN_INDEX_NOOP.
3311 */
3316 ){
3320 }
3323 /* Could not find an existing table or index to use as the RHS b-tree.
3324 ** We will have to generate an ephemeral table to do the job.
3325 */
3333 }
3338 }
3340 }
3346 }
3349 }
3350 #endif
3352 #ifndef SQLITE_OMIT_SUBQUERY
3353 /*
3354 ** Argument pExpr is an (?, ?...) IN(...) expression. This
3355 ** function allocates and returns a nul-terminated string containing
3356 ** the affinities to be used for each column of the comparison.
3357 **
3358 ** It is the responsibility of the caller to ensure that the returned
3359 ** string is eventually freed using sqlite3DbFree().
3360 */
3378 }
3379 }
3381 }
3383 }
3384 #endif
3386 #ifndef SQLITE_OMIT_SUBQUERY
3387 /*
3388 ** Load the Parse object passed as the first argument with an error
3389 ** message of the form:
3390 **
3391 ** "sub-select returns N columns - expected M"
3392 */
3397 }
3398 }
3399 #endif
3401 /*
3402 ** Expression pExpr is a vector that has been used in a context where
3403 ** it is not permitted. If pExpr is a sub-select vector, this routine
3404 ** loads the Parse object with a message of the form:
3405 **
3406 ** "sub-select returns N columns - expected 1"
3407 **
3408 ** Or, if it is a regular scalar vector:
3409 **
3410 ** "row value misused"
3411 */
3413 #ifndef SQLITE_OMIT_SUBQUERY
3417 #endif
3418 {
3420 }
3421 }
3423 #ifndef SQLITE_OMIT_SUBQUERY
3424 /*
3425 ** Generate code that will construct an ephemeral table containing all terms
3426 ** in the RHS of an IN operator. The IN operator can be in either of two
3427 ** forms:
3428 **
3429 ** x IN (4,5,11) -- IN operator with list on right-hand side
3430 ** x IN (SELECT a FROM b) -- IN operator with subquery on the right
3431 **
3432 ** The pExpr parameter is the IN operator. The cursor number for the
3433 ** constructed ephemeral table is returned. The first time the ephemeral
3434 ** table is computed, the cursor number is also stored in pExpr->iTable,
3435 ** however the cursor number returned might not be the same, as it might
3436 ** have been duplicated using OP_OpenDup.
3437 **
3438 ** If the LHS expression ("x" in the examples) is a column value, or
3439 ** the SELECT statement returns a column value, then the affinity of that
3440 ** column is used to build the index keys. If both 'x' and the
3441 ** SELECT... statement are columns, then numeric affinity is used
3442 ** if either column has NUMERIC or INTEGER affinity. If neither
3443 ** 'x' nor the SELECT... statement are columns, then numeric affinity
3444 ** is used.
3445 */
3450 ){
3461 /* The evaluation of the IN must be repeated every time it
3462 ** is encountered if any of the following is true:
3463 **
3464 ** * The right-hand side is a correlated subquery
3465 ** * The right-hand side is an expression list containing variables
3466 ** * We are inside a trigger
3467 **
3468 ** If all of the above are false, then we can compute the RHS just once
3469 ** and reuse it many names.
3470 */
3472 /* Reuse of the RHS is allowed */
3473 /* If this routine has already been coded, but the previous code
3474 ** might not have been invoked yet, so invoke it now as a subroutine.
3475 */
3481 }
3489 }
3491 /* Begin coding the subroutine */
3500 }
3502 /* Check to see if this is a vector IN operator */
3506 /* Construct the ephemeral table that will contain the content of
3507 ** RHS of the IN operator.
3508 */
3511 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
3516 }
3517 #endif
3521 /* Case 1: expr IN (SELECT ...)
3522 **
3523 ** Generate code to write the results of the select into the temporary
3524 ** table allocated and opened above.
3525 */
3531 ));
3532 /* If the LHS and RHS of the IN operator do not match, that
3533 ** error will have been caught long before we reach this point. */
3536 SelectDest dest;
3551 }
3560 );
3561 }
3562 }
3564 /* Case 2: expr IN (exprlist)
3565 **
3566 ** For each expression, build an index key from the evaluation and
3567 ** store it in the temporary table. If <expr> is a column, then use
3568 ** that columns affinity when building index keys. If <expr> is not
3569 ** a column, use numeric affinity.
3570 */
3581 }
3585 }
3587 /* Loop through each expression in <exprlist>. */
3593 /* If the expression is not constant then we will need to
3594 ** disable the test that was generated above that makes sure
3595 ** this code only executes once. Because for a non-constant
3596 ** expression we need to rerun this code each time.
3597 */
3603 }
3605 /* Evaluate the expression and insert it into the temp table */
3609 }
3612 }
3615 }
3619 /* Subroutine return */
3627 }
3628 }
3631 /*
3632 ** Generate code for scalar subqueries used as a subquery expression
3633 ** or EXISTS operator:
3634 **
3635 ** (SELECT a FROM b) -- subquery
3636 ** EXISTS (SELECT a FROM b) -- EXISTS subquery
3637 **
3638 ** The pExpr parameter is the SELECT or EXISTS operator to be coded.
3639 **
3640 ** Return the register that holds the result. For a multi-column SELECT,
3641 ** the result is stored in a contiguous array of registers and the
3642 ** return value is the register of the left-most result column.
3643 ** Return 0 if an error occurs.
3644 */
3645 #ifndef SQLITE_OMIT_SUBQUERY
3653 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
3655 #endif
3666 /* If this routine has already been coded, then invoke it as a
3667 ** subroutine. */
3674 }
3676 /* Begin coding the subroutine */
3684 /* The evaluation of the EXISTS/SELECT must be repeated every time it
3685 ** is encountered if any of the following is true:
3686 **
3687 ** * The right-hand side is a correlated subquery
3688 ** * The right-hand side is an expression list containing variables
3689 ** * We are inside a trigger
3690 **
3691 ** If all of the above are false, then we can run this code just once
3692 ** save the results, and reuse the same result on subsequent invocations.
3693 */
3696 }
3698 /* For a SELECT, generate code to put the values for all columns of
3699 ** the first row into an array of registers and return the index of
3700 ** the first register.
3701 **
3702 ** If this is an EXISTS, write an integer 0 (not exists) or 1 (exists)
3703 ** into a register and return that register number.
3704 **
3705 ** In both cases, the query is augmented with "LIMIT 1". Any
3706 ** preexisting limit is discarded in place of the new LIMIT 1.
3707 */
3724 }
3726 /* The subquery already has a limit. If the pre-existing limit is X
3727 ** then make the new limit X<>0 so that the new limit is either 1 or 0 */
3734 }
3738 /* If there is no pre-existing limit add a limit of 1 */
3741 }
3747 }
3752 }
3755 /* Subroutine return */
3764 }
3767 #ifndef SQLITE_OMIT_SUBQUERY
3768 /*
3769 ** Expr pIn is an IN(...) expression. This function checks that the
3770 ** sub-select on the RHS of the IN() operator has the same number of
3771 ** columns as the vector on the LHS. Or, if the RHS of the IN() is not
3772 ** a sub-query, that the LHS is a vector of size 1.
3773 */
3780 }
3784 }
3786 }
3787 #endif
3789 #ifndef SQLITE_OMIT_SUBQUERY
3790 /*
3791 ** Generate code for an IN expression.
3792 **
3793 ** x IN (SELECT ...)
3794 ** x IN (value, value, ...)
3795 **
3796 ** The left-hand side (LHS) is a scalar or vector expression. The
3797 ** right-hand side (RHS) is an array of zero or more scalar values, or a
3798 ** subquery. If the RHS is a subquery, the number of result columns must
3799 ** match the number of columns in the vector on the LHS. If the RHS is
3800 ** a list of values, the LHS must be a scalar.
3801 **
3802 ** The IN operator is true if the LHS value is contained within the RHS.
3803 ** The result is false if the LHS is definitely not in the RHS. The
3804 ** result is NULL if the presence of the LHS in the RHS cannot be
3805 ** determined due to NULLs.
3806 **
3807 ** This routine generates code that jumps to destIfFalse if the LHS is not
3808 ** contained within the RHS. If due to NULLs we cannot determine if the LHS
3809 ** is contained in the RHS then jump to destIfNull. If the LHS is contained
3810 ** within the RHS then fall through.
3811 **
3812 ** See the separate in-operator.md documentation file in the canonical
3813 ** SQLite source tree for additional information.
3814 */
3820 ){
3847 );
3850 /* Attempt to compute the RHS. After this step, if anything other than
3851 ** IN_INDEX_NOOP is returned, the table opened with cursor iTab
3852 ** contains the values that make up the RHS. If IN_INDEX_NOOP is returned,
3853 ** the RHS has not yet been coded. */
3864 );
3865 #ifdef SQLITE_DEBUG
3866 /* Confirm that aiMap[] contains nVector integer values between 0 and
3867 ** nVector-1. */
3872 }
3873 #endif
3875 /* Code the LHS, the <expr> from "<expr> IN (...)". If the LHS is a
3876 ** vector, then it is stored in an array of nVector registers starting
3877 ** at r1.
3878 **
3879 ** sqlite3FindInIndex() might have reordered the fields of the LHS vector
3880 ** so that the fields are in the same order as an existing index. The
3881 ** aiMap[] array contains a mapping from the original LHS field order to
3882 ** the field order that matches the RHS index.
3883 **
3884 ** Avoid factoring the LHS of the IN(...) expression out of the loop,
3885 ** even if it is constant, as OP_Affinity may be used on the register
3886 ** by code generated below. */
3893 /* LHS fields are not reordered */
3896 /* Need to reorder the LHS fields according to aiMap */
3900 }
3901 }
3903 /* If sqlite3FindInIndex() did not find or create an index that is
3904 ** suitable for evaluating the IN operator, then evaluate using a
3905 ** sequence of comparisons.
3906 **
3907 ** This is step (1) in the in-operator.md optimized algorithm.
3908 */
3922 }
3927 }
3946 }
3947 }
3951 }
3955 }
3957 /* Step 2: Check to see if the LHS contains any NULL columns. If the
3958 ** LHS does contain NULLs then the result must be either FALSE or NULL.
3959 ** We will then skip the binary search of the RHS.
3960 */
3965 }
3972 }
3973 }
3975 /* Step 3. The LHS is now known to be non-NULL. Do the binary search
3976 ** of the RHS using the LHS as a probe. If found, the result is
3977 ** true.
3978 */
3980 /* In this case, the RHS is the ROWID of table b-tree and so we also
3981 ** know that the RHS is non-NULL. Hence, we combine steps 3 and 4
3982 ** into a single opcode. */
3989 /* Combine Step 3 and Step 5 into a single opcode */
3993 }
3994 /* Ordinary Step 3, for the case where FALSE and NULL are distinct */
3997 }
3999 /* Step 4. If the RHS is known to be non-NULL and we did not find
4000 ** an match on the search above, then the result must be FALSE.
4001 */
4005 }
4007 /* Step 5. If we do not care about the difference between NULL and
4008 ** FALSE, then just return false.
4009 */
4012 /* Step 6: Loop through rows of the RHS. Compare each row to the LHS.
4013 ** If any comparison is NULL, then the result is NULL. If all
4014 ** comparisons are FALSE then the final result is FALSE.
4015 **
4016 ** For a scalar LHS, it is sufficient to check just the first row
4017 ** of the RHS.
4018 */
4025 /* For nVector==1, combine steps 6 and 7 by immediately returning
4026 ** FALSE if the first comparison is not NULL */
4028 }
4040 }
4047 /* Step 7: If we reach this point, we know that the result must
4048 ** be false. */
4050 }
4052 /* Jumps here in order to return true. */
4055 sqlite3ExprCodeIN_finished:
4058 sqlite3ExprCodeIN_oom_error:
4061 }
4064 #ifndef SQLITE_OMIT_FLOATING_POINT
4065 /*
4066 ** Generate an instruction that will put the floating point
4067 ** value described by z[0..n-1] into register iMem.
4068 **
4069 ** The z[] string will probably not be zero-terminated. But the
4070 ** z[n] character is guaranteed to be something that does not look
4071 ** like the continuation of the number.
4072 */
4080 }
4081 }
4082 #endif
4085 /*
4086 ** Generate an instruction that will put the integer describe by
4087 ** text z[0..n-1] into register iMem.
4088 **
4089 ** Expr.u.zToken is always UTF8 and zero-terminated.
4090 */
4100 i64 value;
4105 #ifdef SQLITE_OMIT_FLOATING_POINT
4107 #else
4108 #ifndef SQLITE_OMIT_HEX_INTEGER
4113 #endif
4114 {
4116 }
4117 #endif
4121 }
4122 }
4123 }
4126 /* Generate code that will load into register regOut a value that is
4127 ** appropriate for the iIdxCol-th column of index pIdx.
4128 */
4135 ){
4146 }
4147 }
4149 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
4150 /*
4151 ** Generate code that will compute the value of generated column pCol
4152 ** and store the result in register regOut
4153 */
4159 ){
4169 }
4173 }
4176 }
4179 /*
4180 ** Generate code to extract the value of the iCol-th column of a table.
4181 */
4188 ){
4202 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
4215 }
4217 #endif
4226 }
4229 }
4230 }
4232 /*
4233 ** Generate code that will extract the iColumn-th column from
4234 ** table pTab and store the column value in register iReg.
4235 **
4236 ** There must be an open cursor to pTab in iTable when this routine
4237 ** is called. If iColumn<0 then code is generated that extracts the rowid.
4238 */
4245 u8 p5 /* P5 value for OP_Column + FLAGS */
4246 ){
4255 }
4257 }
4259 /*
4260 ** Generate code to move content from registers iFrom...iFrom+nReg-1
4261 ** over to iTo..iTo+nReg-1.
4262 */
4265 }
4267 /*
4268 ** Convert a scalar expression node to a TK_REGISTER referencing
4269 ** register iReg. The caller must ensure that iReg already contains
4270 ** the correct value for the expression.
4271 */
4282 }
4283 }
4285 /*
4286 ** Evaluate an expression (either a vector or a scalar expression) and store
4287 ** the result in contiguous temporary registers. Return the index of
4288 ** the first register used to store the result.
4289 **
4290 ** If the returned result register is a temporary scalar, then also write
4291 ** that register number into *piFreeable. If the returned result register
4292 ** is not a temporary or if the expression is a vector set *piFreeable
4293 ** to 0.
4294 */
4303 #if SQLITE_OMIT_SUBQUERY
4305 #else
4307 #endif
4315 }
4316 }
4317 }
4319 }
4321 /*
4322 ** If the last opcode is a OP_Copy, then set the do-not-merge flag (p5)
4323 ** so that a subsequent copy will not be merged into this one.
4324 */
4328 }
4329 }
4331 /*
4332 ** Generate code to implement special SQL functions that are implemented
4333 ** in-line rather than by using the usual callbacks.
4334 */
4340 ){
4349 /* Attempt a direct implementation of the built-in COALESCE() and
4350 ** IFNULL() functions. This avoids unnecessary evaluation of
4351 ** arguments past the first non-NULL argument.
4352 */
4361 }
4365 }
4367 Expr caseExpr;
4372 }
4373 #ifdef SQLITE_ENABLE_OFFSET_SQL_FUNC
4380 }
4382 }
4383 #endif
4385 /* The UNLIKELY() function is a no-op. The result is the value
4386 ** of the first argument.
4387 */
4391 }
4393 /***********************************************************************
4394 ** Test-only SQL functions that are only usable if enabled
4395 ** via SQLITE_TESTCTRL_INTERNAL_FUNCTIONS
4396 */
4397 #if !defined(SQLITE_UNTESTABLE)
4399 /* Compare two expressions using sqlite3ExprCompare() */
4403 target);
4405 }
4408 /* Compare two expressions using sqlite3ExprImpliesExpr() */
4412 target);
4414 }
4417 /* Result of sqlite3ExprImpliesNonNullRow() */
4424 target);
4427 }
4429 }
4432 /* The AFFINITY() function evaluates to a string that describes
4433 ** the type affinity of the argument. This is used for testing of
4434 ** the SQLite type logic.
4435 */
4446 }
4448 }
4450 }
4452 /*
4453 ** Check to see if pExpr is one of the indexed expressions on pParse->pIdxEpr.
4454 ** If it is, then resolve the expression by reading from the index and
4455 ** return the register into which the value has been read. If pExpr is
4456 ** not an indexed expression, then return negative.
4457 */
4462 ){
4466 u8 exprAff;
4472 }
4479 ){
4480 /* Affinity mismatch on a generated column */
4482 }
4487 /* If the index is on a NULL row due to an outer join, then we
4488 ** cannot extract the value from the index. The value must be
4489 ** computed using the original expression. */
4504 }
4506 }
4508 }
4511 /*
4512 ** Expresion pExpr is guaranteed to be a TK_COLUMN or equivalent. This
4513 ** function checks the Parse.pIdxPartExpr list to see if this column
4514 ** can be replaced with a constant value. If so, it generates code to
4515 ** put the constant value in a register (ideally, but not necessarily,
4516 ** register iTarget) and returns the register number.
4517 **
4518 ** Or, if the TK_COLUMN cannot be replaced by a constant, zero is
4519 ** returned.
4520 */
4531 }
4538 }
4540 }
4541 }
4543 }
4546 /*
4547 ** Generate code into the current Vdbe to evaluate the given
4548 ** expression. Attempt to store the results in register "target".
4549 ** Return the register where results are stored.
4550 **
4551 ** With this routine, there is no guarantee that results will
4552 ** be stored in target. The result might be stored in some other
4553 ** register if it is convenient to do so. The calling function
4554 ** must check the return code and move the results to the desired
4555 ** register.
4556 */
4570 expr_code_doover:
4576 ){
4581 }
4590 /* Happens when the left table of a RIGHT JOIN is null and
4591 ** is using an expression index */
4593 #ifdef SQLITE_VDBE_COVERAGE
4594 /* Verify that the OP_Null above is exercised by tests
4595 ** tag-20230325-2 */
4598 #endif
4600 }
4609 /* No comment added */
4617 }
4618 }
4621 /* This case happens when the argument to an aggregate function
4622 ** is rewritten by aggregateConvertIndexedExprRefToColumn() */
4625 }
4626 /* Otherwise, fall thru into the TK_COLUMN case */
4627 /* no break */ deliberate_fall_through
4628 }
4633 /* This COLUMN expression is really a constant due to WHERE clause
4634 ** constraints, and that constant is coded by the pExpr->pLeft
4635 ** expression. However, make sure the constant has the correct
4636 ** datatype by applying the Affinity of the table column to the
4637 ** constant.
4638 */
4650 }
4652 }
4655 /* Other columns in the same row for CHECK constraints or
4656 ** generated columns or for inserting into partial index.
4657 ** The row is unpacked into registers beginning at
4658 ** 0-(pParse->iSelfTab). The rowid (if any) is in a register
4659 ** immediately prior to the first column.
4660 */
4672 }
4676 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
4682 }
4686 }
4697 }
4699 /* Coding an expression that is part of an index where column names
4700 ** in the index refer to the table to which the index belongs */
4702 }
4703 }
4706 ){
4708 }
4715 }
4719 }
4723 }
4724 #ifndef SQLITE_OMIT_FLOATING_POINT
4729 }
4730 #endif
4735 }
4737 /* Make NULL the default case so that if a bug causes an illegal
4738 ** Expr node to be passed into this function, it will be handled
4739 ** sanely and not crash. But keep the assert() to bring the problem
4740 ** to the attention of the developers. */
4744 }
4745 #ifndef SQLITE_OMIT_BLOB_LITERAL
4759 }
4760 #endif
4767 }
4770 }
4771 #ifndef SQLITE_OMIT_CAST
4773 /* Expressions of the form: CAST(pLeft AS token) */
4780 }
4786 /* fall-through */
4813 }
4816 }
4818 }
4848 }
4855 #ifndef SQLITE_OMIT_FLOATING_POINT
4860 #endif
4870 }
4872 }
4881 }
4893 }
4908 }
4914 ){
4919 }
4921 }
4933 #ifndef SQLITE_OMIT_WINDOWFUNC
4936 }
4937 #endif
4941 ){
4942 /* SQL functions can be expensive. So try to avoid running them
4943 ** multiple times if we know they always give the same result */
4945 }
4953 #ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
4956 }
4957 #endif
4961 }
4969 }
4975 }
4978 }
4979 }
4986 }
4988 /* For length() and typeof() and octet_length() functions,
4989 ** set the P5 parameter to the OP_Column opcode to OPFLAG_LENGTHARG
4990 ** or OPFLAG_TYPEOFARG or OPFLAG_BYTELENARG respectively, to avoid
4991 ** unnecessary data loading.
4992 */
4994 u8 exprOp;
5007 }
5008 }
5013 }
5014 #ifndef SQLITE_OMIT_VIRTUALTABLE
5015 /* Possibly overload the function if the first argument is
5016 ** a virtual table column.
5017 **
5018 ** For infix functions (LIKE, GLOB, REGEXP, and MATCH) use the
5019 ** second argument, not the first, as the argument to test to
5020 ** see if it is a column in a virtual table. This is done because
5021 ** the left operand of infix functions (the operand we want to
5022 ** control overloading) ends up as the second argument to the
5023 ** function. The expression "A glob B" is equivalent to
5024 ** "glob(B,A). We want to use the A in "A glob B" to test
5025 ** for function overloading. But we use the B term in "glob(B,A)".
5026 */
5031 }
5032 #endif
5036 }
5044 }
5045 }
5047 }
5048 #ifndef SQLITE_OMIT_SUBQUERY
5059 ){
5063 }
5065 }
5072 }
5078 }
5080 }
5091 }
5095 /*
5096 ** x BETWEEN y AND z
5097 **
5098 ** This is equivalent to
5099 **
5100 ** x>=y AND x<=z
5101 **
5102 ** X is stored in pExpr->pLeft.
5103 ** Y is stored in pExpr->pList->a[0].pExpr.
5104 ** Z is stored in pExpr->pList->a[1].pExpr.
5105 */
5109 }
5112 /* A TK_COLLATE Expr node without the EP_Collate tag is a so-called
5113 ** "SOFT-COLLATE" that is added to constraints that are pushed down
5114 ** from outer queries into sub-queries by the WHERE-clause push-down
5115 ** optimization. Clear subtypes as subtypes may not cross a subquery
5116 ** boundary.
5117 */
5125 }
5126 }
5131 }
5134 /* If the opcode is TK_TRIGGER, then the expression is a reference
5135 ** to a column in the new.* or old.* pseudo-tables available to
5136 ** trigger programs. In this case Expr.iTable is set to 1 for the
5137 ** new.* pseudo-table, or 0 for the old.* pseudo-table. Expr.iColumn
5138 ** is set to the column of the pseudo-table to read, or to -1 to
5139 ** read the rowid field.
5140 **
5141 ** The expression is implemented using an OP_Param opcode. The p1
5142 ** parameter is set to 0 for an old.rowid reference, or to (i+1)
5143 ** to reference another column of the old.* pseudo-table, where
5144 ** i is the index of the column. For a new.rowid reference, p1 is
5145 ** set to (n+1), where n is the number of columns in each pseudo-table.
5146 ** For a reference to any other column in the new.* pseudo-table, p1
5147 ** is set to (n+2+i), where n and i are as defined previously. For
5148 ** example, if the table on which triggers are being fired is
5149 ** declared as:
5150 **
5151 ** CREATE TABLE t1(a, b);
5152 **
5153 ** Then p1 is interpreted as follows:
5154 **
5155 ** p1==0 -> old.rowid p1==3 -> new.rowid
5156 ** p1==1 -> old.a p1==4 -> new.a
5157 ** p1==2 -> old.b p1==5 -> new.b
5158 */
5178 ));
5180 #ifndef SQLITE_OMIT_FLOATING_POINT
5181 /* If the column has REAL affinity, it may currently be stored as an
5182 ** integer. Use OP_RealAffinity to make sure it is really real.
5183 **
5184 ** EVIDENCE-OF: R-60985-57662 SQLite will convert the value back to
5185 ** floating point when extracting it from the record. */
5188 }
5189 #endif
5191 }
5196 }
5198 /* TK_IF_NULL_ROW Expr nodes are inserted ahead of expressions
5199 ** that derive from the right-hand table of a LEFT JOIN. The
5200 ** Expr.iTable value is the table number for the right-hand table.
5201 ** The expression is only evaluated if that table is not currently
5202 ** on a LEFT JOIN NULL row.
5203 */
5213 }
5217 target);
5220 }
5221 }
5223 /* The OP_IfNullRow opcode above can overwrite the result register with
5224 ** NULL. So we have to ensure that the result register is not a value
5225 ** that is suppose to be a constant. Two defenses are needed:
5226 ** (1) Temporarily disable factoring of constant expressions
5227 ** (2) Make sure the computed value really is stored in register
5228 ** "target" and not someplace else.
5229 */
5236 }
5238 /*
5239 ** Form A:
5240 ** CASE x WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
5241 **
5242 ** Form B:
5243 ** CASE WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
5244 **
5245 ** Form A is can be transformed into the equivalent form B as follows:
5246 ** CASE WHEN x=e1 THEN r1 WHEN x=e2 THEN r2 ...
5247 ** WHEN x=eN THEN rN ELSE y END
5248 **
5249 ** X (if it exists) is in pExpr->pLeft.
5250 ** Y is in the last element of pExpr->x.pList if pExpr->x.pList->nExpr is
5251 ** odd. The Y is also optional. If the number of elements in x.pList
5252 ** is even, then Y is omitted and the "otherwise" result is NULL.
5253 ** Ei is in pExpr->pList->a[i*2] and Ri is pExpr->pList->a[i*2+1].
5254 **
5255 ** The result of the expression is the Ri for the first matching Ei,
5256 ** or if there is no matching Ei, the ELSE term Y, or if there is
5257 ** no ELSE term, NULL.
5258 */
5283 }
5291 /* Ticket b351d95f9cd5ef17e9d9dbae18f5ca8611190001:
5292 ** The value in regFree1 might get SCopy-ed into the file result.
5293 ** So make sure that the regFree1 register is not reused for other
5294 ** purposes and possibly overwritten. */
5296 }
5303 }
5311 }
5316 }
5321 }
5322 #ifndef SQLITE_OMIT_TRIGGER
5328 );
5333 }
5336 }
5346 }
5348 }
5349 #endif
5350 }
5354 }
5356 /*
5357 ** Generate code that will evaluate expression pExpr just one time
5358 ** per prepared statement execution.
5359 **
5360 ** If the expression uses functions (that might throw an exception) then
5361 ** guard them with an OP_Once opcode to ensure that the code is only executed
5362 ** once. If no functions are involved, then factor the code out and put it at
5363 ** the end of the prepared statement in the initialization section.
5364 **
5365 ** If regDest>0 then the result is always stored in that register and the
5366 ** result is not reusable. If regDest<0 then this routine is free to
5367 ** store the value wherever it wants. The register where the expression
5368 ** is stored is returned. When regDest<0, two identical expressions might
5369 ** code to the same register, if they do not contain function calls and hence
5370 ** are factored out into the initialization section at the end of the
5371 ** prepared statement.
5372 */
5377 ){
5388 ){
5390 }
5391 }
5392 }
5403 }
5414 }
5416 }
5418 }
5420 /*
5421 ** Generate code to evaluate an expression and store the results
5422 ** into a register. Return the register number where the results
5423 ** are stored.
5424 **
5425 ** If the register is a temporary register that can be deallocated,
5426 ** then write its number into *pReg. If the result register is not
5427 ** a temporary, then set *pReg to zero.
5428 **
5429 ** If pExpr is a constant, then this routine might generate this
5430 ** code to fill the register in the initialization section of the
5431 ** VDBE program, in order to factor it out of the evaluation loop.
5432 */
5440 ){
5451 }
5452 }
5454 }
5456 /*
5457 ** Generate code that will evaluate expression pExpr and store the
5458 ** results in register target. The results are guaranteed to appear
5459 ** in register target.
5460 */
5470 u8 op;
5475 ){
5479 }
5481 }
5482 }
5484 /*
5485 ** Make a transient copy of expression pExpr and then code it using
5486 ** sqlite3ExprCode(). This routine works just like sqlite3ExprCode()
5487 ** except that the input expression is guaranteed to be unchanged.
5488 */
5494 }
5496 /*
5497 ** Generate code that will evaluate expression pExpr and store the
5498 ** results in register target. The results are guaranteed to appear
5499 ** in register target. If the expression is constant, then this routine
5500 ** might choose to code the expression at initialization time.
5501 */
5507 }
5508 }
5510 /*
5511 ** Generate code that pushes the value of every element of the given
5512 ** expression list into a sequence of registers beginning at target.
5513 **
5514 ** Return the number of elements evaluated. The number returned will
5515 ** usually be pList->nExpr but might be reduced if SQLITE_ECEL_OMITREF
5516 ** is defined.
5517 **
5518 ** The SQLITE_ECEL_DUP flag prevents the arguments from being
5519 ** filled using OP_SCopy. OP_Copy must be used instead.
5520 **
5521 ** The SQLITE_ECEL_FACTOR argument allows constant arguments to be
5522 ** factored out into initialization code.
5523 **
5524 ** The SQLITE_ECEL_REF flag means that expressions in the list with
5525 ** ExprList.a[].u.x.iOrderByCol>0 have already been evaluated and stored
5526 ** in registers at srcReg, and so the value can be copied from there.
5527 ** If SQLITE_ECEL_OMITREF is also set, then the values with u.x.iOrderByCol>0
5528 ** are simply omitted rather than being copied from srcReg.
5529 */
5535 u8 flags /* SQLITE_ECEL_* flags */
5536 ){
5548 #ifdef SQLITE_ENABLE_SORTER_REFERENCES
5550 i--;
5551 n--;
5553 #endif
5556 i--;
5557 n--;
5560 }
5563 ){
5574 ){
5578 }
5579 }
5580 }
5581 }
5583 }
5585 /*
5586 ** Generate code for a BETWEEN operator.
5587 **
5588 ** x BETWEEN y AND z
5589 **
5590 ** The above is equivalent to
5591 **
5592 ** x>=y AND x<=z
5593 **
5594 ** Code it as such, taking care to do the common subexpression
5595 ** elimination of x.
5596 **
5597 ** The xJumpIf parameter determines details:
5598 **
5599 ** NULL: Store the boolean result in reg[dest]
5600 ** sqlite3ExprIfTrue: Jump to dest if true
5601 ** sqlite3ExprIfFalse: Jump to dest if false
5602 **
5603 ** The jumpIfNull parameter is ignored if xJumpIf is NULL.
5604 */
5611 ){
5639 /* Mark the expression is being from the ON or USING clause of a join
5640 ** so that the sqlite3ExprCodeTarget() routine will not attempt to move
5641 ** it into the Parse.pConstExpr list. We should use a new bit for this,
5642 ** for clarity, but we are out of bits in the Expr.flags field so we
5643 ** have to reuse the EP_OuterON bit. Bummer. */
5646 }
5648 }
5651 /* Ensure adequate test coverage */
5661 }
5663 /*
5664 ** Generate code for a boolean expression such that a jump is made
5665 ** to the label "dest" if the expression is true but execution
5666 ** continues straight thru if the expression is false.
5667 **
5668 ** If the expression evaluates to NULL (neither true nor false), then
5669 ** take the jump if the jumpIfNull flag is SQLITE_JUMPIFNULL.
5670 **
5671 ** This code depends on the fact that certain token values (ex: TK_EQ)
5672 ** are the same as opcode values (ex: OP_Eq) that implement the corresponding
5673 ** operation. Special comments in vdbe.c and the mkopcodeh.awk script in
5674 ** the make process cause these values to align. Assert()s in the code
5675 ** below verify that the numbers are aligned correctly.
5676 */
5706 }
5708 }
5713 }
5728 }
5730 }
5737 /* no break */ deliberate_fall_through
5763 }
5775 }
5780 }
5781 #ifndef SQLITE_OMIT_SUBQUERY
5789 }
5790 #endif
5792 default_expr:
5796 /* No-op */
5803 }
5805 }
5806 }
5809 }
5811 /*
5812 ** Generate code for a boolean expression such that a jump is made
5813 ** to the label "dest" if the expression is false but execution
5814 ** continues straight thru if the expression is true.
5815 **
5816 ** If the expression evaluates to NULL (neither true nor false) then
5817 ** jump if jumpIfNull is SQLITE_JUMPIFNULL or fall through if jumpIfNull
5818 ** is 0.
5819 */
5832 /* The value of pExpr->op and op are related as follows:
5833 **
5834 ** pExpr->op op
5835 ** --------- ----------
5836 ** TK_ISNULL OP_NotNull
5837 ** TK_NOTNULL OP_IsNull
5838 ** TK_NE OP_Eq
5839 ** TK_EQ OP_Ne
5840 ** TK_GT OP_Le
5841 ** TK_LE OP_Gt
5842 ** TK_GE OP_Lt
5843 ** TK_LT OP_Ge
5844 **
5845 ** For other values of pExpr->op, op is undefined and unused.
5846 ** The value of TK_ and OP_ constants are arranged such that we
5847 ** can compute the mapping above using the following expression.
5848 ** Assert()s verify that the computation is correct.
5849 */
5852 /* Verify correct alignment of TK_ and OP_ constants
5853 */
5880 }
5882 }
5887 }
5897 /* IS TRUE and IS NOT FALSE */
5902 /* IS FALSE and IS NOT TRUE */
5905 }
5907 }
5914 /* no break */ deliberate_fall_through
5940 }
5950 }
5955 }
5956 #ifndef SQLITE_OMIT_SUBQUERY
5964 }
5966 }
5967 #endif
5969 default_expr:
5973 /* no-op */
5980 }
5982 }
5983 }
5986 }
5988 /*
5989 ** Like sqlite3ExprIfFalse() except that a copy is made of pExpr before
5990 ** code generation, and that copy is deleted after code generation. This
5991 ** ensures that the original pExpr is unchanged.
5992 */
5998 }
6000 }
6002 /*
6003 ** Expression pVar is guaranteed to be an SQL variable. pExpr may be any
6004 ** type of expression.
6005 **
6006 ** If pExpr is a simple SQL value - an integer, real, string, blob
6007 ** or NULL value - then the VDBE currently being prepared is configured
6008 ** to re-prepare each time a new value is bound to variable pVar.
6009 **
6010 ** Additionally, if pExpr is a simple SQL value and the value is the
6011 ** same as that currently bound to variable pVar, non-zero is returned.
6012 ** Otherwise, if the values are not the same or if pExpr is not a simple
6013 ** SQL value, zero is returned.
6014 */
6019 ){
6032 }
6034 }
6037 }
6040 }
6042 /*
6043 ** Do a deep comparison of two expression trees. Return 0 if the two
6044 ** expressions are completely identical. Return 1 if they differ only
6045 ** by a COLLATE operator at the top level. Return 2 if there are differences
6046 ** other than the top-level COLLATE operator.
6047 **
6048 ** If any subelement of pB has Expr.iTable==(-1) then it is allowed
6049 ** to compare equal to an equivalent element in pA with Expr.iTable==iTab.
6050 **
6051 ** The pA side might be using TK_REGISTER. If that is the case and pB is
6052 ** not using TK_REGISTER but is otherwise equivalent, then still return 0.
6053 **
6054 ** Sometimes this routine will return 2 even if the two expressions
6055 ** really are equivalent. If we cannot prove that the expressions are
6056 ** identical, we return 2 just to be safe. So if this routine
6057 ** returns 2, then you do not really know for certain if the two
6058 ** expressions are the same. But if you get a 0 or 1 return, then you
6059 ** can be sure the expressions are the same. In the places where
6060 ** this routine is used, it does not hurt to get an extra 2 - that
6061 ** just might result in some slightly slower code. But returning
6062 ** an incorrect 0 or 1 could lead to a malfunction.
6063 **
6064 ** If pParse is not NULL then TK_VARIABLE terms in pA with bindings in
6065 ** pParse->pReprepare can be matched against literals in pB. The
6066 ** pParse->pVdbe->expmask bitmask is updated for each variable referenced.
6067 ** If pParse is NULL (the normal case) then any TK_VARIABLE term in
6068 ** Argument pParse should normally be NULL. If it is not NULL and pA or
6069 ** pB causes a return value of 2.
6070 */
6075 int iTab
6076 ){
6077 u32 combinedFlags;
6080 }
6083 }
6088 }
6090 }
6094 }
6097 }
6100 ){
6101 /* fall through */
6104 }
6105 }
6111 #ifndef SQLITE_OMIT_WINDOWFUNC
6115 }
6119 }
6120 }
6121 #endif
6131 ){
6133 }
6134 }
6146 ){
6151 }
6152 }
6153 }
6155 }
6157 /*
6158 ** Compare two ExprList objects. Return 0 if they are identical, 1
6159 ** if they are certainly different, or 2 if it is not possible to
6160 ** determine if they are identical or not.
6161 **
6162 ** If any subelement of pB has Expr.iTable==(-1) then it is allowed
6163 ** to compare equal to an equivalent element in pA with Expr.iTable==iTab.
6164 **
6165 ** This routine might return non-zero for equivalent ExprLists. The
6166 ** only consequence will be disabled optimizations. But this routine
6167 ** must never return 0 if the two ExprList objects are different, or
6168 ** a malfunction will result.
6169 **
6170 ** Two NULL pointers are considered to be the same. But a NULL pointer
6171 ** always differs from a non-NULL pointer.
6172 */
6184 }
6186 }
6188 /*
6189 ** Like sqlite3ExprCompare() except COLLATE operators at the top-level
6190 ** are ignored.
6191 */
6196 iTab);
6197 }
6199 /*
6200 ** Return non-zero if Expr p can only be true if pNN is not NULL.
6201 **
6202 ** Or if seenNot is true, return non-zero if Expr p can only be
6203 ** non-NULL if pNN is not NULL
6204 */
6211 ){
6216 }
6222 }
6232 ){
6234 }
6236 }
6250 /* no break */ deliberate_fall_through
6256 /* no break */ deliberate_fall_through
6257 }
6263 }
6268 }
6272 }
6273 }
6275 }
6277 /*
6278 ** Return true if we can prove the pE2 will always be true if pE1 is
6279 ** true. Return false if we cannot complete the proof or if pE2 might
6280 ** be false. Examples:
6281 **
6282 ** pE1: x==5 pE2: x==5 Result: true
6283 ** pE1: x>0 pE2: x==5 Result: false
6284 ** pE1: x=21 pE2: x=21 OR y=43 Result: true
6285 ** pE1: x!=123 pE2: x IS NOT NULL Result: true
6286 ** pE1: x!=?1 pE2: x IS NOT NULL Result: true
6287 ** pE1: x IS NULL pE2: x IS NOT NULL Result: false
6288 ** pE1: x IS ?2 pE2: x IS NOT NULL Result: false
6289 **
6290 ** When comparing TK_COLUMN nodes between pE1 and pE2, if pE2 has
6291 ** Expr.iTable<0 then assume a table number given by iTab.
6292 **
6293 ** If pParse is not NULL, then the values of bound variables in pE1 are
6294 ** compared against literal values in pE2 and pParse->pVdbe->expmask is
6295 ** modified to record which bound variables are referenced. If pParse
6296 ** is NULL, then false will be returned if pE1 contains any bound variables.
6297 **
6298 ** When in doubt, return false. Returning true might give a performance
6299 ** improvement. Returning false might cause a performance reduction, but
6300 ** it will always give the correct answer and is hence always safe.
6301 */
6306 int iTab
6307 ){
6310 }
6314 ){
6316 }
6319 ){
6321 }
6323 }
6325 /* This is a helper function to impliesNotNullRow(). In this routine,
6326 ** set pWalker->eCode to one only if *both* of the input expressions
6327 ** separately have the implies-not-null-row property.
6328 */
6335 }
6336 }
6337 }
6339 /*
6340 ** This is the Expr node callback for sqlite3ExprImpliesNonNullRow().
6341 ** If the expression node requires that the table at pWalker->iCur
6342 ** have one or more non-NULL column, then set pWalker->eCode to 1 and abort.
6343 **
6344 ** pWalker->mWFlags is non-zero if this inquiry is being undertaking on
6345 ** behalf of a RIGHT JOIN (or FULL JOIN). That makes a difference when
6346 ** evaluating terms in the ON clause of an inner join.
6347 **
6348 ** This routine controls an optimization. False positives (setting
6349 ** pWalker->eCode to 1 when it should not be) are deadly, but false-negatives
6350 ** (never setting pWalker->eCode) is a harmless missed optimization.
6351 */
6357 /* If iCur is used in an inner-join ON clause to the left of a
6358 ** RIGHT JOIN, that does *not* mean that the table must be non-null.
6359 ** But it is difficult to check for that condition precisely.
6360 ** To keep things simple, any use of iCur from any inner-join is
6361 ** ignored while attempting to simplify a RIGHT JOIN. */
6363 }
6387 }
6392 /* Both sides of an AND or OR must separately imply non-null-row.
6393 ** Consider these cases:
6394 ** 1. NOT (x AND y)
6395 ** 2. x OR y
6396 ** If only one of x or y is non-null-row, then the overall expression
6397 ** can be true if the other arm is false (case 1) or true (case 2).
6398 */
6405 /* Beware of "x NOT IN ()" and "x NOT IN (SELECT 1 WHERE false)",
6406 ** both of which can be true. But apart from these cases, if
6407 ** the left-hand side of the IN is NULL then the IN itself will be
6408 ** NULL. */
6411 }
6415 /* In "x NOT BETWEEN y AND z" either x must be non-null-row or else
6416 ** both y and z must be non-null row */
6424 /* Virtual tables are allowed to use constraints like x=NULL. So
6425 ** a term of the form x=y does not prove that y is not null if x
6426 ** is the column of a virtual table */
6441 /* The y.pTab=0 assignment in wherecode.c always happens after the
6442 ** impliesNotNullRow() test */
6451 ){
6453 }
6454 /* no break */ deliberate_fall_through
6455 }
6458 }
6459 }
6461 /*
6462 ** Return true (non-zero) if expression p can only be true if at least
6463 ** one column of table iTab is non-null. In other words, return true
6464 ** if expression p will always be NULL or false if every column of iTab
6465 ** is NULL.
6466 **
6467 ** False negatives are acceptable. In other words, it is ok to return
6468 ** zero even if expression p will never be true of every column of iTab
6469 ** is NULL. A false negative is merely a missed optimization opportunity.
6470 **
6471 ** False positives are not allowed, however. A false positive may result
6472 ** in an incorrect answer.
6473 **
6474 ** Terms of p that are marked with EP_OuterON (and hence that come from
6475 ** the ON or USING clauses of OUTER JOINS) are excluded from the analysis.
6476 **
6477 ** This routine is used to check if a LEFT JOIN can be converted into
6478 ** an ordinary JOIN. The p argument is the WHERE clause. If the WHERE
6479 ** clause requires that some column of the right table of the LEFT JOIN
6480 ** be non-NULL, then the LEFT JOIN can be safely converted into an
6481 ** ordinary join.
6482 */
6484 Walker w;
6493 }
6494 }
6503 }
6505 /*
6506 ** An instance of the following structure is used by the tree walker
6507 ** to determine if an expression can be evaluated by reference to the
6508 ** index only, without having to do a search for the corresponding
6509 ** table entry. The IdxCover.pIdx field is the index. IdxCover.iCur
6510 ** is the cursor for the table.
6511 */
6515 };
6517 /*
6518 ** Check to see if there are references to columns in table
6519 ** pWalker->u.pIdxCover->iCur can be satisfied using the index
6520 ** pWalker->u.pIdxCover->pIdx.
6521 */
6526 ){
6529 }
6531 }
6533 /*
6534 ** Determine if an index pIdx on table with cursor iCur contains will
6535 ** the expression pExpr. Return true if the index does cover the
6536 ** expression and false if the pExpr expression references table columns
6537 ** that are not found in the index pIdx.
6538 **
6539 ** An index covering an expression means that the expression can be
6540 ** evaluated using only the index and without having to lookup the
6541 ** corresponding table entry.
6542 */
6547 ){
6548 Walker w;
6557 }
6560 /* Structure used to pass information throughout the Walker in order to
6561 ** implement sqlite3ReferencesSrcList().
6562 */
6568 };
6570 /*
6571 ** Walker SELECT callbacks for sqlite3ReferencesSrcList().
6572 **
6573 ** When entering a new subquery on the pExpr argument, add all FROM clause
6574 ** entries for that subquery to the exclude list.
6575 **
6576 ** When leaving the subquery, remove those entries from the exclude list.
6577 */
6592 }
6595 }
6597 }
6604 }
6605 }
6607 /* This is the Walker EXPR callback for sqlite3ReferencesSrcList().
6608 **
6609 ** Set the 0x01 bit of pWalker->eCode if there is a reference to any
6610 ** of the tables shown in RefSrcList.pRef.
6611 **
6612 ** Set the 0x02 bit of pWalker->eCode if there is a reference to a
6613 ** table is in neither RefSrcList.pRef nor RefSrcList.aiExclude.
6614 */
6618 ){
6627 }
6628 }
6632 }
6633 }
6635 }
6637 /*
6638 ** Check to see if pExpr references any tables in pSrcList.
6639 ** Possible return values:
6640 **
6641 ** 1 pExpr does references a table in pSrcList.
6642 **
6643 ** 0 pExpr references some table that is not defined in either
6644 ** pSrcList or in subqueries of pExpr itself.
6645 **
6646 ** -1 pExpr only references no tables at all, or it only
6647 ** references tables defined in subqueries of pExpr itself.
6648 **
6649 ** As currently used, pExpr is always an aggregate function call. That
6650 ** fact is exploited for efficiency.
6651 */
6653 Walker w;
6672 }
6673 #ifndef SQLITE_OMIT_WINDOWFUNC
6676 }
6677 #endif
6685 }
6686 }
6688 /*
6689 ** This is a Walker expression node callback.
6690 **
6691 ** For Expr nodes that contain pAggInfo pointers, make sure the AggInfo
6692 ** object that is referenced does not refer directly to the Expr. If
6693 ** it does, make a copy. This is done because the pExpr argument is
6694 ** subject to change.
6695 **
6696 ** The copy is scheduled for deletion using the sqlite3ExprDeferredDelete()
6697 ** which builds on the sqlite3ParserAddCleanup() mechanism.
6698 */
6702 ){
6711 ){
6715 }
6716 }
6721 ){
6725 }
6726 }
6727 }
6728 }
6730 }
6732 /*
6733 ** Initialize a Walker object so that will persist AggInfo entries referenced
6734 ** by the tree that is walked.
6735 */
6741 }
6743 /*
6744 ** Add a new element to the pAggInfo->aCol[] array. Return the index of
6745 ** the new element. Return a negative number if malloc fails.
6746 */
6750 db,
6754 &i
6755 );
6757 }
6759 /*
6760 ** Add a new element to the pAggInfo->aFunc[] array. Return the index of
6761 ** the new element. Return a negative number if malloc fails.
6762 */
6766 db,
6770 &i
6771 );
6773 }
6775 /*
6776 ** Search the AggInfo object for an aCol[] entry that has iTable and iColumn.
6777 ** Return the index in aCol[] of the entry that describes that column.
6778 **
6779 ** If no prior entry is found, create a new one and return -1. The
6780 ** new column will have an index of pAggInfo->nColumn-1.
6781 */
6786 ){
6797 ){
6799 }
6800 }
6803 /* OOM on resize */
6806 }
6824 ){
6827 }
6828 }
6829 }
6832 }
6833 fix_up_expr:
6839 }
6841 }
6843 /*
6844 ** This is the xExprCallback for a tree walker. It is used to
6845 ** implement sqlite3ExprAnalyzeAggregates(). See sqlite3ExprAnalyzeAggregates
6846 ** for additional information.
6847 */
6860 Expr tmp;
6868 }
6873 }
6878 /* If we reach this point, it means that expression pExpr can be
6879 ** translated into a reference to an index column as described by
6880 ** pIEpr.
6881 */
6894 }
6901 /* Check to see if the column is in one of the tables in the FROM
6902 ** clause of the aggregate query */
6912 }
6914 }
6919 ){
6920 /* Check to see if pExpr is a duplicate of another aggregate
6921 ** function that is already in the pAggInfo structure
6922 */
6928 }
6929 }
6931 /* pExpr is original. Make a new entry in pAggInfo->aFunc[]
6932 */
6947 ){
6948 /* The NEEDCOLL test above causes any ORDER BY clause on
6949 ** aggregate min() or max() to be ignored. */
6962 ){
6967 }
6972 }
6977 }
6978 }
6979 }
6980 /* Make pExpr point to the appropriate pAggInfo->aFunc[] entry
6981 */
6989 }
6990 }
6991 }
6993 }
6995 /*
6996 ** Analyze the pExpr expression looking for aggregate functions and
6997 ** for variables that need to be added to AggInfo object that pNC->pAggInfo
6998 ** points to. Additional entries are made on the AggInfo object as
6999 ** necessary.
7000 **
7001 ** This routine should only be called after the expression has been
7002 ** analyzed by sqlite3ResolveExprNames().
7003 */
7005 Walker w;
7014 }
7016 /*
7017 ** Call sqlite3ExprAnalyzeAggregates() for every expression in an
7018 ** expression list. Return the number of errors.
7019 **
7020 ** If an error is found, the analysis is cut short.
7021 */
7028 }
7029 }
7030 }
7032 /*
7033 ** Allocate a single new register for use to hold some intermediate result.
7034 */
7038 }
7040 }
7042 /*
7043 ** Deallocate a register, making available for reuse for some other
7044 ** purpose.
7045 */
7051 }
7052 }
7053 }
7055 /*
7056 ** Allocate or deallocate a block of nReg consecutive registers.
7057 */
7069 }
7071 }
7076 }
7081 }
7082 }
7084 /*
7085 ** Mark all temporary registers as being unavailable for reuse.
7086 **
7087 ** Always invoke this procedure after coding a subroutine or co-routine
7088 ** that might be invoked from other parts of the code, to ensure that
7089 ** the sub/co-routine does not use registers in common with the code that
7090 ** invokes the sub/co-routine.
7091 */
7095 }
7097 /*
7098 ** Make sure sufficient registers have been allocated so that
7099 ** iReg is a valid register number.
7100 */
7103 }
7105 #if defined(SQLITE_ENABLE_STAT4) || defined(SQLITE_DEBUG)
7106 /*
7107 ** Return the latest reusable register in the set of all registers.
7108 ** The value returned is no less than iMin. If any register iMin or
7109 ** greater is in permanent use, then return one more than that last
7110 ** permanent register.
7111 */
7119 }
7120 }
7121 }
7125 }
7128 /*
7129 ** Validate that no temporary register falls within the range of
7130 ** iFirst..iLast, inclusive. This routine is only call from within assert()
7131 ** statements.
7132 */
7133 #ifdef SQLITE_DEBUG
7139 ){
7141 }
7145 }
7146 }
7153 }
7154 }
7156 }