| blob | f9b280bbc5762c027952b8574d7e65fd8cc4b40c |
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 }
89 }
91 }
93 /*
94 ** Make a guess at all the possible datatypes of the result that could
95 ** be returned by an expression. Return a bitmask indicating the answer:
96 **
97 ** 0x01 Numeric
98 ** 0x02 Text
99 ** 0x04 Blob
100 **
101 ** If the expression must return NULL, then 0x00 is returned.
102 */
111 }
115 }
118 }
121 }
124 }
129 }
140 }
149 }
152 }
154 }
157 }
161 }
163 /*
164 ** Set the collating sequence for expression pExpr to be the collating
165 ** sequence named by pToken. Return a pointer to a new Expr node that
166 ** implements the COLLATE operator.
167 **
168 ** If a memory allocation error occurs, that fact is recorded in pParse->db
169 ** and the pExpr parameter is returned unchanged.
170 */
176 ){
183 }
184 }
186 }
191 ){
192 Token s;
196 }
198 /*
199 ** Skip over any TK_COLLATE operators.
200 */
205 }
207 }
209 /*
210 ** Skip over any TK_COLLATE operators and/or any unlikely()
211 ** or likelihood() or likely() functions at the root of an
212 ** expression.
213 */
224 }
225 }
227 }
229 /*
230 ** Return the collation sequence for the expression pExpr. If
231 ** there is no defined collating sequence, return NULL.
232 **
233 ** See also: sqlite3ExprNNCollSeq()
234 **
235 ** The sqlite3ExprNNCollSeq() works the same exact that it returns the
236 ** default collation if pExpr has no defined collation.
237 **
238 ** The collating sequence might be determined by a COLLATE operator
239 ** or by the presence of a column with a defined collating sequence.
240 ** COLLATE operators take first precedence. Left operands take
241 ** precedence over right operands.
242 */
252 ){
259 }
261 }
265 }
270 }
275 }
281 /* The Expr.x union is never used at the same time as Expr.pRight */
289 }
290 }
291 }
293 }
296 }
297 }
300 }
302 }
304 /*
305 ** Return the collation sequence for the expression pExpr. If
306 ** there is no defined collating sequence, return a pointer to the
307 ** default collation sequence.
308 **
309 ** See also: sqlite3ExprCollSeq()
310 **
311 ** The sqlite3ExprCollSeq() routine works the same except that it
312 ** returns NULL if there is no defined collation.
313 */
319 }
321 /*
322 ** Return TRUE if the two expressions have equivalent collating sequences.
323 */
328 }
330 /*
331 ** pExpr is an operand of a comparison operator. aff2 is the
332 ** type affinity of the other operand. This routine returns the
333 ** type affinity that should be used for the comparison operator.
334 */
338 /* Both sides of the comparison are columns. If one has numeric
339 ** affinity, use that. Otherwise use no affinity.
340 */
345 }
347 /* One side is a column, the other is not. Use the columns affinity. */
350 }
351 }
353 /*
354 ** pExpr is a comparison operator. Return the type affinity that should
355 ** be applied to both operands prior to doing the comparison.
356 */
370 }
372 }
374 /*
375 ** pExpr is a comparison expression, eg. '=', '<', IN(...) etc.
376 ** idx_affinity is the affinity of an indexed column. Return true
377 ** if the index with affinity idx_affinity may be used to implement
378 ** the comparison in pExpr.
379 */
384 }
387 }
389 }
391 /*
392 ** Return the P5 value that should be used for a binary comparison
393 ** opcode (OP_Eq, OP_Ge etc.) used to compare pExpr1 and pExpr2.
394 */
399 ){
403 }
405 /*
406 ** Return a pointer to the collation sequence that should be used by
407 ** a binary comparison operator comparing pLeft and pRight.
408 **
409 ** If the left hand expression has a collating sequence type, then it is
410 ** used. Otherwise the collation sequence for the right hand expression
411 ** is used, or the default (BINARY) if neither expression has a collating
412 ** type.
413 **
414 ** Argument pRight (but not pLeft) may be a null pointer. In this case,
415 ** it is not considered.
416 */
421 ){
432 }
433 }
435 }
437 /* Expression p is a comparison operator. Return a collation sequence
438 ** appropriate for the comparison operator.
439 **
440 ** This is normally just a wrapper around sqlite3BinaryCompareCollSeq().
441 ** However, if the OP_Commuted flag is set, then the order of the operands
442 ** is reversed in the sqlite3BinaryCompareCollSeq() call so that the
443 ** correct collating sequence is found.
444 */
450 }
451 }
453 /*
454 ** Generate code for a comparison operator.
455 */
465 ){
475 }
481 }
483 /*
484 ** Return true if expression pExpr is a vector, or false otherwise.
485 **
486 ** A vector is defined as any expression that results in two or more
487 ** columns of result. Every TK_VECTOR node is an vector because the
488 ** parser will not generate a TK_VECTOR with fewer than two entries.
489 ** But a TK_SELECT might be either a vector or a scalar. It is only
490 ** considered a vector if it has two or more result columns.
491 */
494 }
496 /*
497 ** If the expression passed as the only argument is of type TK_VECTOR
498 ** return the number of expressions in the vector. Or, if the expression
499 ** is a sub-select, return the number of columns in the sub-select. For
500 ** any other type of expression, return 1.
501 */
513 }
514 }
516 /*
517 ** Return a pointer to a subexpression of pVector that is the i-th
518 ** column of the vector (numbered starting with 0). The caller must
519 ** ensure that i is within range.
520 **
521 ** If pVector is really a scalar (and "scalar" here includes subqueries
522 ** that return a single column!) then return pVector unmodified.
523 **
524 ** pVector retains ownership of the returned subexpression.
525 **
526 ** If the vector is a (SELECT ...) then the expression returned is
527 ** just the expression for the i-th term of the result set, and may
528 ** not be ready for evaluation because the table cursor has not yet
529 ** been positioned.
530 */
541 }
542 }
544 }
546 /*
547 ** Compute and return a new Expr object which when passed to
548 ** sqlite3ExprCode() will generate all necessary code to compute
549 ** the iField-th column of the vector expression pVector.
550 **
551 ** It is ok for pVector to be a scalar (as long as iField==0).
552 ** In that case, this routine works like sqlite3ExprDup().
553 **
554 ** The caller owns the returned Expr object and is responsible for
555 ** ensuring that the returned value eventually gets freed.
556 **
557 ** The caller retains ownership of pVector. If pVector is a TK_SELECT,
558 ** then the returned object will reference pVector and so pVector must remain
559 ** valid for the life of the returned object. If pVector is a TK_VECTOR
560 ** or a scalar expression, then it can be deleted as soon as this routine
561 ** returns.
562 **
563 ** A trick to cause a TK_SELECT pVector to be deleted together with
564 ** the returned Expr object is to attach the pVector to the pRight field
565 ** of the returned TK_SELECT_COLUMN Expr object.
566 */
572 ){
576 /* The TK_SELECT_COLUMN Expr node:
577 **
578 ** pLeft: pVector containing TK_SELECT. Not deleted.
579 ** pRight: not used. But recursively deleted.
580 ** iColumn: Index of a column in pVector
581 ** iTable: 0 or the number of columns on the LHS of an assignment
582 ** pLeft->iTable: First in an array of register holding result, or 0
583 ** if the result is not yet computed.
584 **
585 ** sqlite3ExprDelete() specifically skips the recursive delete of
586 ** pLeft on TK_SELECT_COLUMN nodes. But pRight is followed, so pVector
587 ** can be attached to pRight to cause this node to take ownership of
588 ** pVector. Typically there will be multiple TK_SELECT_COLUMN nodes
589 ** with the same pLeft pointer to the pVector, but only one of them
590 ** will own the pVector.
591 */
598 }
606 /* This must be a vector UPDATE inside a trigger */
609 }
610 }
612 }
614 }
616 /*
617 ** If expression pExpr is of type TK_SELECT, generate code to evaluate
618 ** it. Return the register in which the result is stored (or, if the
619 ** sub-select returns more than one column, the first in an array
620 ** of registers in which the result is stored).
621 **
622 ** If pExpr is not a TK_SELECT expression, return 0.
623 */
626 #ifndef SQLITE_OMIT_SUBQUERY
629 }
630 #endif
632 }
634 /*
635 ** Argument pVector points to a vector expression - either a TK_VECTOR
636 ** or TK_SELECT that returns more than one column. This function returns
637 ** the register number of a register that contains the value of
638 ** element iField of the vector.
639 **
640 ** If pVector is a TK_SELECT expression, then code for it must have
641 ** already been generated using the exprCodeSubselect() routine. In this
642 ** case parameter regSelect should be the first in an array of registers
643 ** containing the results of the sub-select.
644 **
645 ** If pVector is of type TK_VECTOR, then code for the requested field
646 ** is generated. In this case (*pRegFree) may be set to the number of
647 ** a temporary register to be freed by the caller before returning.
648 **
649 ** Before returning, output parameter (*ppExpr) is set to point to the
650 ** Expr object corresponding to element iElem of the vector.
651 */
659 ){
665 }
670 }
675 }
677 }
679 /*
680 ** Expression pExpr is a comparison between two vector values. Compute
681 ** the result of the comparison (1, 0, or NULL) and write that
682 ** result into register dest.
683 **
684 ** The caller must satisfy the following preconditions:
685 **
686 ** if pExpr->op==TK_IS: op==TK_EQ and p5==SQLITE_NULLEQ
687 ** if pExpr->op==TK_ISNOT: op==TK_NE and p5==SQLITE_NULLEQ
688 ** otherwise: op==pExpr->op and p5==0
689 */
695 u8 p5 /* SQLITE_NULLEQ or zero */
696 ){
714 }
719 );
755 }
760 }
763 }
770 }
771 }
776 }
777 }
779 #if SQLITE_MAX_EXPR_DEPTH>0
780 /*
781 ** Check that argument nHeight is less than or equal to the maximum
782 ** expression depth allowed. If it is not, leave an error message in
783 ** pParse.
784 */
791 );
793 }
795 }
797 /* The following three functions, heightOfExpr(), heightOfExprList()
798 ** and heightOfSelect(), are used to determine the maximum height
799 ** of any expression tree referenced by the structure passed as the
800 ** first argument.
801 **
802 ** If this maximum height is greater than the current value pointed
803 ** to by pnHeight, the second parameter, then set *pnHeight to that
804 ** value.
805 */
810 }
811 }
812 }
818 }
819 }
820 }
830 }
831 }
833 /*
834 ** Set the Expr.nHeight variable in the structure passed as an
835 ** argument. An expression with no children, Expr.pList or
836 ** Expr.pSelect member has a height of 1. Any other expression
837 ** has a height equal to the maximum height of any other
838 ** referenced Expr plus one.
839 **
840 ** Also propagate EP_Propagate flags up from Expr.x.pList to Expr.flags,
841 ** if appropriate.
842 */
847 }
853 }
855 }
857 /*
858 ** Set the Expr.nHeight variable using the exprSetHeight() function. If
859 ** the height is greater than the maximum allowed expression depth,
860 ** leave an error in pParse.
861 **
862 ** Also propagate all EP_Propagate flags from the Expr.x.pList into
863 ** Expr.flags.
864 */
869 }
871 /*
872 ** Return the maximum height of any expression tree referenced
873 ** by the select statement passed as an argument.
874 */
879 }
881 /*
882 ** Propagate all EP_Propagate flags from the Expr.x.pList into
883 ** Expr.flags.
884 */
889 }
890 }
891 #define exprSetHeight(y)
894 /*
895 ** Set the error offset for an Expr node, if possible.
896 */
901 }
903 /*
904 ** This routine is the core allocator for Expr nodes.
905 **
906 ** Construct a new expression node and return a pointer to it. Memory
907 ** for this node and for the pToken argument is a single allocation
908 ** obtained from sqlite3DbMalloc(). The calling function
909 ** is responsible for making sure the node eventually gets freed.
910 **
911 ** If dequote is true, then the token (if it exists) is dequoted.
912 ** If dequote is false, no dequoting is performed. The deQuote
913 ** parameter is ignored if pToken is NULL or if the token does not
914 ** appear to be quoted. If the quotes were of the form "..." (double-quotes)
915 ** then the EP_DblQuoted flag is set on the expression node.
916 **
917 ** Special case: If op==TK_INTEGER and pToken points to a string that
918 ** can be translated into a 32-bit integer, then the token is not
919 ** stored in u.zToken. Instead, the integer values is written
920 ** into u.iValue and the EP_IntValue flag is set. No extra storage
921 ** is allocated to hold the integer text and the dequote flag is ignored.
922 */
928 ){
939 }
940 }
957 }
958 }
959 }
960 #if SQLITE_MAX_EXPR_DEPTH>0
962 #endif
963 }
965 }
967 /*
968 ** Allocate a new expression node from a zero-terminated token that has
969 ** already been dequoted.
970 */
975 ){
976 Token x;
980 }
982 /*
983 ** Attach subtrees pLeft and pRight to the Expr node pRoot.
984 **
985 ** If pRoot==NULL that means that a memory allocation error has occurred.
986 ** In that case, delete the subtrees pLeft and pRight.
987 */
992 Expr *pRight
993 ){
1004 #if SQLITE_MAX_EXPR_DEPTH>0
1008 #endif
1009 }
1013 #if SQLITE_MAX_EXPR_DEPTH>0
1016 }
1017 #endif
1018 }
1019 }
1020 }
1022 /*
1023 ** Allocate an Expr node which joins as many as two subtrees.
1024 **
1025 ** One or both of the subtrees can be NULL. Return a pointer to the new
1026 ** Expr node. Or, if an OOM error occurs, set pParse->db->mallocFailed,
1027 ** free the subtrees and return NULL.
1028 */
1034 ){
1046 }
1048 }
1050 /*
1051 ** Add pSelect to the Expr.x.pSelect field. Or, if pExpr is NULL (due
1052 ** do a memory allocation failure) then delete the pSelect object.
1053 */
1062 }
1063 }
1065 /*
1066 ** Expression list pEList is a list of vector values. This function
1067 ** converts the contents of pEList to a VALUES(...) Select statement
1068 ** returning 1 row for each element of the list. For example, the
1069 ** expression list:
1070 **
1071 ** ( (1,2), (3,4) (5,6) )
1072 **
1073 ** is translated to the equivalent of:
1074 **
1075 ** VALUES(1,2), (3,4), (5,6)
1076 **
1077 ** Each of the vector values in pEList must contain exactly nElem terms.
1078 ** If a list element that is not a vector or does not contain nElem terms,
1079 ** an error message is left in pParse.
1080 **
1081 ** This is used as part of processing IN(...) expressions with a list
1082 ** of vectors on the RHS. e.g. "... IN ((1,2), (3,4), (5,6))".
1083 */
1097 }
1101 );
1103 }
1111 }
1113 }
1114 }
1118 }
1121 }
1123 /*
1124 ** Join two expressions using an AND operator. If either expression is
1125 ** NULL, then just return the other expression.
1126 **
1127 ** If one side or the other of the AND is known to be false, and neither side
1128 ** is part of an ON clause, then instead of returning an AND expression,
1129 ** just return a constant expression with a value of false.
1130 */
1140 && !IN_RENAME_OBJECT
1141 ){
1147 }
1148 }
1149 }
1151 /*
1152 ** Construct a new expression node for a function with multiple
1153 ** arguments.
1154 */
1160 ){
1168 }
1174 ){
1176 }
1183 }
1185 /*
1186 ** Report an error when attempting to use an ORDER BY clause within
1187 ** the arguments of a non-aggregate function.
1188 */
1192 );
1193 }
1195 /*
1196 ** Attach an ORDER BY clause to a function call.
1197 **
1198 ** functionname( arguments ORDER BY sortlist )
1199 ** \_____________________/ \______/
1200 ** pExpr pOrderBy
1201 **
1202 ** The ORDER BY clause is inserted into a new Expr node of type TK_ORDER
1203 ** and added to the Expr.pLeft field of the parent TK_FUNCTION node.
1204 */
1209 ){
1215 }
1220 }
1225 /* Ignore ORDER BY on zero-argument aggregates */
1228 }
1233 }
1239 }
1244 }
1246 /*
1247 ** Check to see if a function is usable according to current access
1248 ** rules:
1249 **
1250 ** SQLITE_FUNC_DIRECT - Only usable from top-level SQL
1251 **
1252 ** SQLITE_FUNC_UNSAFE - Usable if TRUSTED_SCHEMA or from
1253 ** top-level SQL
1254 **
1255 ** If the function is not usable, create an error.
1256 */
1261 ){
1267 ){
1268 /* Functions prohibited in triggers and views if:
1269 ** (1) tagged with SQLITE_DIRECTONLY
1270 ** (2) not tagged with SQLITE_INNOCUOUS (which means it
1271 ** is tagged with SQLITE_FUNC_UNSAFE) and
1272 ** SQLITE_DBCONFIG_TRUSTED_SCHEMA is off (meaning
1273 ** that the schema is possibly tainted).
1274 */
1276 }
1277 }
1278 }
1280 /*
1281 ** Assign a variable number to an expression that encodes a wildcard
1282 ** in the original SQL statement.
1283 **
1284 ** Wildcards consisting of a single "?" are assigned the next sequential
1285 ** variable number.
1286 **
1287 ** Wildcards of the form "?nnn" are assigned the number "nnn". We make
1288 ** sure "nnn" is not too big to avoid a denial of service attack when
1289 ** the SQL statement comes from an external source.
1290 **
1291 ** Wildcards of the form ":aaa", "@aaa", or "$aaa" are assigned the same number
1292 ** as the previous instance of the same wildcard. Or if this is the first
1293 ** instance of the wildcard, the next sequential variable number is
1294 ** assigned.
1295 */
1299 ynVar x;
1308 /* Wildcard of the form "?". Assign the next variable number */
1314 /* Wildcard of the form "?nnn". Convert "nnn" to an integer and
1315 ** use it as the variable number */
1316 i64 i;
1323 }
1333 }
1340 }
1342 /* Wildcards like ":aaa", "$aaa" or "@aaa". Reuse the same variable
1343 ** number as the prior appearance of the same name, or if the name
1344 ** has never appeared before, reuse the same variable number
1345 */
1350 }
1351 }
1354 }
1355 }
1360 }
1361 }
1363 /*
1364 ** Recursively delete an expression tree.
1365 */
1373 #ifdef SQLITE_DEBUG
1379 }
1380 #endif
1382 /* The Expr.x union is never used at the same time as Expr.pRight */
1393 #ifndef SQLITE_OMIT_WINDOWFUNC
1396 }
1397 #endif
1398 }
1399 }
1402 }
1403 }
1406 }
1409 }
1411 /*
1412 ** Clear both elements of an OnOrUsing object
1413 */
1416 /* Nothing to clear */
1421 }
1422 }
1424 /*
1425 ** Arrange to cause pExpr to be deleted when the pParse is deleted.
1426 ** This is similar to sqlite3ExprDelete() except that the delete is
1427 ** deferred until the pParse is deleted.
1428 **
1429 ** The pExpr might be deleted immediately on an OOM error.
1430 **
1431 ** The deferred delete is (currently) implemented by adding the
1432 ** pExpr to the pParse->pConstExpr list with a register number of 0.
1433 */
1436 }
1438 /* Invoke sqlite3RenameExprUnmap() and sqlite3ExprDelete() on the
1439 ** expression.
1440 */
1445 }
1447 }
1448 }
1450 /*
1451 ** Return the number of bytes allocated for the expression structure
1452 ** passed as the first argument. This is always one of EXPR_FULLSIZE,
1453 ** EXPR_REDUCEDSIZE or EXPR_TOKENONLYSIZE.
1454 */
1459 }
1461 /*
1462 ** The dupedExpr*Size() routines each return the number of bytes required
1463 ** to store a copy of an expression or expression tree. They differ in
1464 ** how much of the tree is measured.
1465 **
1466 ** dupedExprStructSize() Size of only the Expr structure
1467 ** dupedExprNodeSize() Size of Expr + space for token
1468 ** dupedExprSize() Expr + token + subtree components
1469 **
1470 ***************************************************************************
1471 **
1472 ** The dupedExprStructSize() function returns two values OR-ed together:
1473 ** (1) the space required for a copy of the Expr structure only and
1474 ** (2) the EP_xxx flags that indicate what the structure size should be.
1475 ** The return values is always one of:
1476 **
1477 ** EXPR_FULLSIZE
1478 ** EXPR_REDUCEDSIZE | EP_Reduced
1479 ** EXPR_TOKENONLYSIZE | EP_TokenOnly
1480 **
1481 ** The size of the structure can be found by masking the return value
1482 ** of this routine with 0xfff. The flags can be found by masking the
1483 ** return value with EP_Reduced|EP_TokenOnly.
1484 **
1485 ** Note that with flags==EXPRDUP_REDUCE, this routines works on full-size
1486 ** (unreduced) Expr objects as they or originally constructed by the parser.
1487 ** During expression analysis, extra information is computed and moved into
1488 ** later parts of the Expr object and that extra information might get chopped
1489 ** off if the expression is reduced. Note also that it does not work to
1490 ** make an EXPRDUP_REDUCE copy of a reduced expression. It is only legal
1491 ** to reduce a pristine expression tree from the parser. The implementation
1492 ** of dupedExprStructSize() contain multiple assert() statements that attempt
1493 ** to enforce this constraint.
1494 */
1511 }
1512 }
1514 }
1516 /*
1517 ** This function returns the space in bytes required to store the copy
1518 ** of the Expr structure and a copy of the Expr.u.zToken string (if that
1519 ** string is defined.)
1520 */
1525 }
1527 }
1529 /*
1530 ** Return the number of bytes required to create a duplicate of the
1531 ** expression passed as the first argument.
1532 **
1533 ** The value returned includes space to create a copy of the Expr struct
1534 ** itself and the buffer referred to by Expr.u.zToken, if any.
1535 **
1536 ** The return value includes space to duplicate all Expr nodes in the
1537 ** tree formed by Expr.pLeft and Expr.pRight, but not any other
1538 ** substructure such as Expr.x.pList, Expr.x.pSelect, and Expr.y.pWin.
1539 */
1548 }
1550 /*
1551 ** An EdupBuf is a memory allocation used to stored multiple Expr objects
1552 ** together with their Expr.zToken content. This is used to help implement
1553 ** compression while doing sqlite3ExprDup(). The top-level Expr does the
1554 ** allocation for itself and many of its decendents, then passes an instance
1555 ** of the structure down into exprDup() so that they decendents can have
1556 ** access to that memory.
1557 */
1561 #ifdef SQLITE_DEBUG
1563 #endif
1564 };
1566 /*
1567 ** This function is similar to sqlite3ExprDup(), except that if pEdupBuf
1568 ** is not NULL then it points to memory that can be used to store a copy
1569 ** of the input Expr p together with its p->u.zToken (if any). pEdupBuf
1570 ** is updated with the new buffer tail prior to returning.
1571 */
1577 ){
1588 /* Figure out where to write the new Expr structure. */
1591 #ifdef SQLITE_DEBUG
1593 #endif
1607 }
1610 #ifdef SQLITE_DEBUG
1612 #endif
1615 }
1620 /* Set nNewSize to the size allocated for the structure pointed to
1621 ** by pNew. This is either EXPR_FULLSIZE, EXPR_REDUCEDSIZE or
1622 ** EXPR_TOKENONLYSIZE. nToken is set to the number of bytes consumed
1623 ** by the copy of the p->u.zToken string (if any).
1624 */
1632 }
1633 }
1645 }
1647 }
1649 /* Set the EP_Reduced, EP_TokenOnly, and EP_Static flags appropriately. */
1656 }
1658 /* Copy the p->u.zToken string, if any. */
1664 }
1669 /* Fill in the pNew->x.pSelect or pNew->x.pList member. */
1675 }
1677 #ifndef SQLITE_OMIT_WINDOWFUNC
1681 }
1684 /* Fill in pNew->pLeft and pNew->pRight. */
1694 }
1705 }
1707 }
1708 }
1709 }
1713 }
1715 /*
1716 ** Create and return a deep copy of the object passed as the second
1717 ** argument. If an OOM condition is encountered, NULL is returned
1718 ** and the db->mallocFailed flag set.
1719 */
1720 #ifndef SQLITE_OMIT_CTE
1734 }
1735 }
1736 }
1738 }
1739 #else
1740 # define sqlite3WithDup(x,y) 0
1741 #endif
1743 #ifndef SQLITE_OMIT_WINDOWFUNC
1744 /*
1745 ** The gatherSelectWindows() procedure and its helper routine
1746 ** gatherSelectWindowsCallback() are used to scan all the expressions
1747 ** an a newly duplicated SELECT statement and gather all of the Window
1748 ** objects found there, assembling them onto the linked list at Select->pWin.
1749 */
1758 }
1760 }
1763 }
1765 Walker w;
1772 }
1773 #endif
1776 /*
1777 ** The following group of routines make deep copies of expressions,
1778 ** expression lists, ID lists, and select statements. The copies can
1779 ** be deleted (by being passed to their respective ...Delete() routines)
1780 ** without effecting the originals.
1781 **
1782 ** The expression list, ID, and source lists return by sqlite3ExprListDup(),
1783 ** sqlite3IdListDup(), and sqlite3SrcListDup() can not be further expanded
1784 ** by subsequent calls to sqlite*ListAppend() routines.
1785 **
1786 ** Any tables that the SrcList might point to are not duplicated.
1787 **
1788 ** The flags parameter contains a combination of the EXPRDUP_XXX flags.
1789 ** If the EXPRDUP_REDUCE flag is set, then the structure returned is a
1790 ** truncated version of the usual Expr structure that will be stored as
1791 ** part of the in-memory representation of the database schema.
1792 */
1796 }
1819 ){
1829 }
1831 }
1832 }
1837 }
1839 }
1841 /*
1842 ** If cursors, triggers, views and subqueries are all omitted from
1843 ** the build, then none of the following routines, except for
1844 ** sqlite3SelectDup(), can be called. sqlite3SelectDup() is sometimes
1845 ** called with a NULL argument.
1846 */
1847 #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER) \
1848 || !defined(SQLITE_OMIT_SUBQUERY)
1873 }
1877 }
1881 }
1885 }
1892 }
1894 }
1896 }
1912 }
1914 }
1942 #ifndef SQLITE_OMIT_WINDOWFUNC
1946 #endif
1949 /* Any prior OOM might have left the Select object incomplete.
1950 ** Delete the whole thing rather than allow an incomplete Select
1951 ** to be used by the code generator. */
1955 }
1959 }
1962 }
1963 #else
1967 }
1968 #endif
1971 /*
1972 ** Add a new element to the end of an expression list. If pList is
1973 ** initially NULL, then create a new expression list.
1974 **
1975 ** The pList argument must be either NULL or a pointer to an ExprList
1976 ** obtained from a prior call to sqlite3ExprListAppend().
1977 **
1978 ** If a memory allocation error occurs, the entire list is freed and
1979 ** NULL is returned. If non-NULL is returned, then it is guaranteed
1980 ** that the new entry was successfully appended.
1981 */
1986 ){
1994 }
2001 }
2006 ){
2018 }
2023 }
2028 ){
2032 }
2035 }
2040 }
2042 /*
2043 ** pColumns and pExpr form a vector assignment which is part of the SET
2044 ** clause of an UPDATE statement. Like this:
2045 **
2046 ** (a,b,c) = (expr1,expr2,expr3)
2047 ** Or: (a,b,c) = (SELECT x,y,z FROM ....)
2048 **
2049 ** For each term of the vector assignment, append new entries to the
2050 ** expression list pList. In the case of a subquery on the RHS, append
2051 ** TK_SELECT_COLUMN expressions.
2052 */
2058 ){
2063 /* pColumns can only be NULL due to an OOM but an OOM will cause an
2064 ** exit prior to this routine being invoked */
2068 /* If the RHS is a vector, then we can immediately check to see that
2069 ** the size of the RHS and LHS match. But if the RHS is a SELECT,
2070 ** wildcards ("*") in the result set of the SELECT must be expanded before
2071 ** we can do the size check, so defer the size check until code generation.
2072 */
2077 }
2088 }
2089 }
2096 /* Store the SELECT statement in pRight so it will be deleted when
2097 ** sqlite3ExprListDelete() is called */
2101 /* Remember the size of the LHS in iTable so that we can check that
2102 ** the RHS and LHS sizes match during code generation. */
2104 }
2106 vector_append_error:
2110 }
2112 /*
2113 ** Set the sort order for the last element on the given ExprList.
2114 */
2124 );
2128 );
2134 }
2141 }
2142 }
2143 }
2145 /*
2146 ** Set the ExprList.a[].zEName element of the most recently added item
2147 ** on the expression list.
2148 **
2149 ** pList might be NULL following an OOM error. But pName should never be
2150 ** NULL. If a memory allocation fails, the pParse->db->mallocFailed flag
2151 ** is set.
2152 */
2158 ){
2169 /* If dequote==0, then pName->z does not point to part of a DDL
2170 ** statement handled by the parser. And so no token need be added
2171 ** to the token-map. */
2175 }
2176 }
2177 }
2178 }
2180 /*
2181 ** Set the ExprList.a[].zSpan element of the most recently added item
2182 ** on the expression list.
2183 **
2184 ** pList might be NULL following an OOM error. But pSpan should never be
2185 ** NULL. If a memory allocation fails, the pParse->db->mallocFailed flag
2186 ** is set.
2187 */
2193 ){
2202 }
2203 }
2204 }
2206 /*
2207 ** If the expression list pEList contains more than iLimit elements,
2208 ** leave an error message in pParse.
2209 */
2214 ){
2220 }
2221 }
2223 /*
2224 ** Delete an entire expression list.
2225 */
2234 pItem++;
2237 }
2240 }
2243 }
2245 /*
2246 ** Return the bitwise-OR of all Expr.flags fields in the given
2247 ** ExprList.
2248 */
2257 }
2259 }
2261 /*
2262 ** This is a SELECT-node callback for the expression walker that
2263 ** always "fails". By "fail" in this case, we mean set
2264 ** pWalker->eCode to zero and abort.
2265 **
2266 ** This callback is used by multiple expression walkers.
2267 */
2272 }
2274 /*
2275 ** Check the input string to see if it is "true" or "false" (in any case).
2276 **
2277 ** If the string is.... Return
2278 ** "true" EP_IsTrue
2279 ** "false" EP_IsFalse
2280 ** anything else 0
2281 */
2286 }
2289 /*
2290 ** If the input expression is an ID with the name "true" or "false"
2291 ** then convert it into an TK_TRUEFALSE term. Return non-zero if
2292 ** the conversion happened, and zero if the expression is unaltered.
2293 */
2295 u32 v;
2299 ){
2303 }
2305 }
2307 /*
2308 ** The argument must be a TK_TRUEFALSE Expr node. Return 1 if it is TRUE
2309 ** and 0 if it is FALSE.
2310 */
2318 }
2320 /*
2321 ** If pExpr is an AND or OR expression, try to simplify it by eliminating
2322 ** terms that are always true or false. Return the simplified expression.
2323 ** Or return the original expression if no simplification is possible.
2324 **
2325 ** Examples:
2326 **
2327 ** (x<10) AND true => (x<10)
2328 ** (x<10) AND false => false
2329 ** (x<10) AND (y=22 OR false) => (x<10) AND (y=22)
2330 ** (x<10) AND (y=22 OR true) => (x<10)
2331 ** (y=22) OR true => true
2332 */
2342 }
2343 }
2345 }
2348 /*
2349 ** These routines are Walker callbacks used to check expressions to
2350 ** see if they are "constant" for some definition of constant. The
2351 ** Walker.eCode value determines the type of "constant" we are looking
2352 ** for.
2353 **
2354 ** These callback routines are used to implement the following:
2355 **
2356 ** sqlite3ExprIsConstant() pWalker->eCode==1
2357 ** sqlite3ExprIsConstantNotJoin() pWalker->eCode==2
2358 ** sqlite3ExprIsTableConstant() pWalker->eCode==3
2359 ** sqlite3ExprIsConstantOrFunction() pWalker->eCode==4 or 5
2360 **
2361 ** In all cases, the callbacks set Walker.eCode=0 and abort if the expression
2362 ** is found to not be a constant.
2363 **
2364 ** The sqlite3ExprIsConstantOrFunction() is used for evaluating DEFAULT
2365 ** expressions in a CREATE TABLE statement. The Walker.eCode value is 5
2366 ** when parsing an existing schema out of the sqlite_schema table and 4
2367 ** when processing a new CREATE TABLE statement. A bound parameter raises
2368 ** an error for new statements, but is silently converted
2369 ** to NULL for existing schemas. This allows sqlite_schema tables that
2370 ** contain a bound parameter because they were generated by older versions
2371 ** of SQLite to be parsed by newer versions of SQLite without raising a
2372 ** malformed schema error.
2373 */
2376 /* If pWalker->eCode is 2 then any term of the expression that comes from
2377 ** the ON or USING clauses of an outer join disqualifies the expression
2378 ** from being considered constant. */
2382 }
2385 /* Consider functions to be constant if all their arguments are constant
2386 ** and either pWalker->eCode==4 or 5 or the function has the
2387 ** SQLITE_FUNC_CONST flag. */
2391 ){
2397 }
2399 /* Convert "true" or "false" in a DEFAULT clause into the
2400 ** appropriate TK_TRUEFALSE operator */
2403 }
2404 /* no break */ deliberate_fall_through
2414 }
2417 }
2418 /* no break */ deliberate_fall_through
2429 /* Silently convert bound parameters that appear inside of CREATE
2430 ** statements into a NULL when parsing the CREATE statement text out
2431 ** of the sqlite_schema table */
2434 /* A bound parameter in a CREATE statement that originates from
2435 ** sqlite3_prepare() causes an error */
2438 }
2439 /* no break */ deliberate_fall_through
2444 }
2445 }
2447 Walker w;
2451 #ifdef SQLITE_DEBUG
2453 #endif
2457 }
2459 /*
2460 ** Walk an expression tree. Return non-zero if the expression is constant
2461 ** and 0 if it involves variables or function calls.
2462 **
2463 ** For the purposes of this function, a double-quoted string (ex: "abc")
2464 ** is considered a variable but a single-quoted string (ex: 'abc') is
2465 ** a constant.
2466 */
2469 }
2471 /*
2472 ** Walk an expression tree. Return non-zero if
2473 **
2474 ** (1) the expression is constant, and
2475 ** (2) the expression does originate in the ON or USING clause
2476 ** of a LEFT JOIN, and
2477 ** (3) the expression does not contain any EP_FixedCol TK_COLUMN
2478 ** operands created by the constant propagation optimization.
2479 **
2480 ** When this routine returns true, it indicates that the expression
2481 ** can be added to the pParse->pConstExpr list and evaluated once when
2482 ** the prepared statement starts up. See sqlite3ExprCodeRunJustOnce().
2483 */
2486 }
2488 /*
2489 ** Walk an expression tree. Return non-zero if the expression is constant
2490 ** for any single row of the table with cursor iCur. In other words, the
2491 ** expression must not refer to any non-deterministic function nor any
2492 ** table other than iCur.
2493 */
2496 }
2498 /*
2499 ** Check pExpr to see if it is an constraint on the single data source
2500 ** pSrc = &pSrcList->a[iSrc]. In other words, check to see if pExpr
2501 ** constrains pSrc but does not depend on any other tables or data
2502 ** sources anywhere else in the query. Return true (non-zero) if pExpr
2503 ** is a constraint on pSrc only.
2504 **
2505 ** This is an optimization. False negatives will perhaps cause slower
2506 ** queries, but false positives will yield incorrect answers. So when in
2507 ** doubt, return 0.
2508 **
2509 ** To be an single-source constraint, the following must be true:
2510 **
2511 ** (1) pExpr cannot refer to any table other than pSrc->iCursor.
2512 **
2513 ** (2) pExpr cannot use subqueries or non-deterministic functions.
2514 **
2515 ** (3) pSrc cannot be part of the left operand for a RIGHT JOIN.
2516 ** (Is there some way to relax this constraint?)
2517 **
2518 ** (4) If pSrc is the right operand of a LEFT JOIN, then...
2519 ** (4a) pExpr must come from an ON clause..
2520 ** (4b) and specifically the ON clause associated with the LEFT JOIN.
2521 **
2522 ** (5) If pSrc is not the right operand of a LEFT JOIN or the left
2523 ** operand of a RIGHT JOIN, then pExpr must be from the WHERE
2524 ** clause, not an ON clause.
2525 **
2526 ** (6) Either:
2527 **
2528 ** (6a) pExpr does not originate in an ON or USING clause, or
2529 **
2530 ** (6b) The ON or USING clause from which pExpr is derived is
2531 ** not to the left of a RIGHT JOIN (or FULL JOIN).
2532 **
2533 ** Without this restriction, accepting pExpr as a single-table
2534 ** constraint might move the the ON/USING filter expression
2535 ** from the left side of a RIGHT JOIN over to the right side,
2536 ** which leads to incorrect answers. See also restriction (9)
2537 ** on push-down.
2538 */
2543 ){
2547 }
2553 }
2556 ){
2562 }
2564 }
2565 }
2566 }
2568 }
2571 /*
2572 ** sqlite3WalkExpr() callback used by sqlite3ExprIsConstantOrGroupBy().
2573 */
2578 /* Check if pExpr is identical to any GROUP BY term. If so, consider
2579 ** it constant. */
2586 }
2587 }
2588 }
2590 /* Check if pExpr is a sub-select. If so, consider it variable. */
2594 }
2597 }
2599 /*
2600 ** Walk the expression tree passed as the first argument. Return non-zero
2601 ** if the expression consists entirely of constants or copies of terms
2602 ** in pGroupBy that sort with the BINARY collation sequence.
2603 **
2604 ** This routine is used to determine if a term of the HAVING clause can
2605 ** be promoted into the WHERE clause. In order for such a promotion to work,
2606 ** the value of the HAVING clause term must be the same for all members of
2607 ** a "group". The requirement that the GROUP BY term must be BINARY
2608 ** assumes that no other collating sequence will have a finer-grained
2609 ** grouping than binary. In other words (A=B COLLATE binary) implies
2610 ** A=B in every other collating sequence. The requirement that the
2611 ** GROUP BY be BINARY is stricter than necessary. It would also work
2612 ** to promote HAVING clauses that use the same alternative collating
2613 ** sequence as the GROUP BY term, but that is much harder to check,
2614 ** alternative collating sequences are uncommon, and this is only an
2615 ** optimization, so we take the easy way out and simply require the
2616 ** GROUP BY to use the BINARY collating sequence.
2617 */
2619 Walker w;
2627 }
2629 /*
2630 ** Walk an expression tree for the DEFAULT field of a column definition
2631 ** in a CREATE TABLE statement. Return non-zero if the expression is
2632 ** acceptable for use as a DEFAULT. That is to say, return non-zero if
2633 ** the expression is constant or a function call with constant arguments.
2634 ** Return and 0 if there are any variables.
2635 **
2636 ** isInit is true when parsing from sqlite_schema. isInit is false when
2637 ** processing a new CREATE TABLE statement. When isInit is true, parameters
2638 ** (such as ? or $abc) in the expression are converted into NULL. When
2639 ** isInit is false, parameters raise an error. Parameters should not be
2640 ** allowed in a CREATE TABLE statement, but some legacy versions of SQLite
2641 ** allowed it, so we need to support it when reading sqlite_schema for
2642 ** backwards compatibility.
2643 **
2644 ** If isInit is true, set EP_FromDDL on every TK_FUNCTION node.
2645 **
2646 ** For the purposes of this function, a double-quoted string (ex: "abc")
2647 ** is considered a variable but a single-quoted string (ex: 'abc') is
2648 ** a constant.
2649 */
2653 }
2655 #ifdef SQLITE_ENABLE_CURSOR_HINTS
2656 /*
2657 ** Walk an expression tree. Return 1 if the expression contains a
2658 ** subquery of some kind. Return 0 if there are no subqueries.
2659 */
2661 Walker w;
2665 #ifdef SQLITE_DEBUG
2667 #endif
2670 }
2671 #endif
2673 /*
2674 ** If the expression p codes a constant integer that is small enough
2675 ** to fit in a 32-bit integer, return 1 and put the value of the integer
2676 ** in *pValue. If the expression is not an integer or if it is too big
2677 ** to fit in a signed 32-bit integer, return 0 and leave *pValue unchanged.
2678 */
2683 /* If an expression is an integer literal that fits in a signed 32-bit
2684 ** integer, then the EP_IntValue flag will have already been set */
2691 }
2696 }
2703 }
2705 }
2707 }
2709 }
2711 /*
2712 ** Return FALSE if there is no chance that the expression can be NULL.
2713 **
2714 ** If the expression might be NULL or if the expression is too complex
2715 ** to tell return TRUE.
2716 **
2717 ** This routine is used as an optimization, to skip OP_IsNull opcodes
2718 ** when we know that a value cannot be NULL. Hence, a false positive
2719 ** (returning TRUE when in fact the expression can never be NULL) might
2720 ** be a small performance hit but is otherwise harmless. On the other
2721 ** hand, a false negative (returning FALSE when the result could be NULL)
2722 ** will likely result in an incorrect answer. So when in doubt, return
2723 ** TRUE.
2724 */
2726 u8 op;
2731 }
2750 }
2751 }
2753 /*
2754 ** Return TRUE if the given expression is a constant which would be
2755 ** unchanged by OP_Affinity with the affinity given in the second
2756 ** argument.
2757 **
2758 ** This routine is used to determine if the OP_Affinity operation
2759 ** can be omitted. When in doubt return FALSE. A false negative
2760 ** is harmless. A false positive, however, can result in the wrong
2761 ** answer.
2762 */
2764 u8 op;
2770 }
2776 }
2779 }
2782 }
2785 }
2789 }
2792 }
2793 }
2794 }
2796 /*
2797 ** Return TRUE if the given string is a row-id column name.
2798 */
2804 }
2806 /*
2807 ** Return a pointer to a buffer containing a usable rowid alias for table
2808 ** pTab. An alias is usable if there is not an explicit user-defined column
2809 ** of the same name.
2810 */
2819 }
2822 }
2823 }
2825 }
2827 /*
2828 ** pX is the RHS of an IN operator. If pX is a SELECT statement
2829 ** that can be simplified to a direct table access, then return
2830 ** a pointer to the SELECT statement. If pX is not a SELECT statement,
2831 ** or if the SELECT statement needs to be materialized into a transient
2832 ** table, then return NULL.
2833 */
2834 #ifndef SQLITE_OMIT_SUBQUERY
2849 }
2863 /* All SELECT results must be columns. */
2868 }
2870 }
2873 #ifndef SQLITE_OMIT_SUBQUERY
2874 /*
2875 ** Generate code that checks the left-most column of index table iCur to see if
2876 ** it contains any NULL entries. Cause the register at regHasNull to be set
2877 ** to a non-NULL value if iCur contains no NULLs. Cause register regHasNull
2878 ** to be set to NULL if iCur contains one or more NULL values.
2879 */
2888 }
2889 #endif
2892 #ifndef SQLITE_OMIT_SUBQUERY
2893 /*
2894 ** The argument is an IN operator with a list (not a subquery) on the
2895 ** right-hand side. Return TRUE if that list is constant.
2896 */
2906 }
2907 #endif
2909 /*
2910 ** This function is used by the implementation of the IN (...) operator.
2911 ** The pX parameter is the expression on the RHS of the IN operator, which
2912 ** might be either a list of expressions or a subquery.
2913 **
2914 ** The job of this routine is to find or create a b-tree object that can
2915 ** be used either to test for membership in the RHS set or to iterate through
2916 ** all members of the RHS set, skipping duplicates.
2917 **
2918 ** A cursor is opened on the b-tree object that is the RHS of the IN operator
2919 ** and the *piTab parameter is set to the index of that cursor.
2920 **
2921 ** The returned value of this function indicates the b-tree type, as follows:
2922 **
2923 ** IN_INDEX_ROWID - The cursor was opened on a database table.
2924 ** IN_INDEX_INDEX_ASC - The cursor was opened on an ascending index.
2925 ** IN_INDEX_INDEX_DESC - The cursor was opened on a descending index.
2926 ** IN_INDEX_EPH - The cursor was opened on a specially created and
2927 ** populated ephemeral table.
2928 ** IN_INDEX_NOOP - No cursor was allocated. The IN operator must be
2929 ** implemented as a sequence of comparisons.
2930 **
2931 ** An existing b-tree might be used if the RHS expression pX is a simple
2932 ** subquery such as:
2933 **
2934 ** SELECT <column1>, <column2>... FROM <table>
2935 **
2936 ** If the RHS of the IN operator is a list or a more complex subquery, then
2937 ** an ephemeral table might need to be generated from the RHS and then
2938 ** pX->iTable made to point to the ephemeral table instead of an
2939 ** existing table. In this case, the creation and initialization of the
2940 ** ephemeral table might be put inside of a subroutine, the EP_Subrtn flag
2941 ** will be set on pX and the pX->y.sub fields will be set to show where
2942 ** the subroutine is coded.
2943 **
2944 ** The inFlags parameter must contain, at a minimum, one of the bits
2945 ** IN_INDEX_MEMBERSHIP or IN_INDEX_LOOP but not both. If inFlags contains
2946 ** IN_INDEX_MEMBERSHIP, then the generated table will be used for a fast
2947 ** membership test. When the IN_INDEX_LOOP bit is set, the IN index will
2948 ** be used to loop over all values of the RHS of the IN operator.
2949 **
2950 ** When IN_INDEX_LOOP is used (and the b-tree will be used to iterate
2951 ** through the set members) then the b-tree must not contain duplicates.
2952 ** An ephemeral table will be created unless the selected columns are guaranteed
2953 ** to be unique - either because it is an INTEGER PRIMARY KEY or due to
2954 ** a UNIQUE constraint or index.
2955 **
2956 ** When IN_INDEX_MEMBERSHIP is used (and the b-tree will be used
2957 ** for fast set membership tests) then an ephemeral table must
2958 ** be used unless <columns> is a single INTEGER PRIMARY KEY column or an
2959 ** index can be found with the specified <columns> as its left-most.
2960 **
2961 ** If the IN_INDEX_NOOP_OK and IN_INDEX_MEMBERSHIP are both set and
2962 ** if the RHS of the IN operator is a list (not a subquery) then this
2963 ** routine might decide that creating an ephemeral b-tree for membership
2964 ** testing is too expensive and return IN_INDEX_NOOP. In that case, the
2965 ** calling routine should implement the IN operator using a sequence
2966 ** of Eq or Ne comparison operations.
2967 **
2968 ** When the b-tree is being used for membership tests, the calling function
2969 ** might need to know whether or not the RHS side of the IN operator
2970 ** contains a NULL. If prRhsHasNull is not a NULL pointer and
2971 ** if there is any chance that the (...) might contain a NULL value at
2972 ** runtime, then a register is allocated and the register number written
2973 ** to *prRhsHasNull. If there is no chance that the (...) contains a
2974 ** NULL value, then *prRhsHasNull is left unchanged.
2975 **
2976 ** If a register is allocated and its location stored in *prRhsHasNull, then
2977 ** the value in that register will be NULL if the b-tree contains one or more
2978 ** NULL values, and it will be some non-NULL value if the b-tree contains no
2979 ** NULL values.
2980 **
2981 ** If the aiMap parameter is not NULL, it must point to an array containing
2982 ** one element for each column returned by the SELECT statement on the RHS
2983 ** of the IN(...) operator. The i'th entry of the array is populated with the
2984 ** offset of the index column that matches the i'th column returned by the
2985 ** SELECT. For example, if the expression and selected index are:
2986 **
2987 ** (?,?,?) IN (SELECT a, b, c FROM t1)
2988 ** CREATE INDEX i1 ON t1(b, c, a);
2989 **
2990 ** then aiMap[] is populated with {2, 0, 1}.
2991 */
2992 #ifndef SQLITE_OMIT_SUBQUERY
3000 ){
3011 /* If the RHS of this IN(...) operator is a SELECT, and if it matters
3012 ** whether or not the SELECT result contains NULL values, check whether
3013 ** or not NULL is actually possible (it may not be, for example, due
3014 ** to NOT NULL constraints in the schema). If no NULL values are possible,
3015 ** set prRhsHasNull to 0 before continuing. */
3021 }
3024 }
3025 }
3027 /* Check to see if an existing table or index can be used to
3028 ** satisfy the query. This is preferable to generating a new
3029 ** ephemeral table. */
3042 /* Code an OP_Transaction and OP_TableLock for <table>. */
3050 /* The "x IN (SELECT rowid FROM table)" case */
3064 /* Check that the affinity that will be used to perform each
3065 ** comparison is the same as the affinity of each column in table
3066 ** on the RHS of the IN operator. If it not, it is not possible to
3067 ** use any index of the RHS table. */
3079 /* sqlite3CompareAffinity() only returns TEXT if one side or the
3080 ** other has no affinity and the other side is TEXT. Hence,
3081 ** the only way for cmpaff to be TEXT is for idxaff to be TEXT
3082 ** and for the term on the LHS of the IN to have no affinity. */
3087 }
3088 }
3091 /* Search for an existing index that will work for this IN operator */
3097 /* Maximum nColumn is BMS-2, not BMS-1, so that we can compute
3098 ** BITMASK(nExpr) without overflowing */
3105 ){
3107 }
3108 }
3122 }
3124 }
3130 }
3134 /* If we reach this point, that means the index pIdx is usable */
3145 #ifdef SQLITE_ENABLE_COLUMN_USED_MASK
3149 #endif
3153 }
3154 }
3156 }
3162 /* If no preexisting index is available for the IN clause
3163 ** and IN_INDEX_NOOP is an allowed reply
3164 ** and the RHS of the IN operator is a list, not a subquery
3165 ** and the RHS is not constant or has two or fewer terms,
3166 ** then it is not worth creating an ephemeral table to evaluate
3167 ** the IN operator so return IN_INDEX_NOOP.
3168 */
3173 ){
3177 }
3180 /* Could not find an existing table or index to use as the RHS b-tree.
3181 ** We will have to generate an ephemeral table to do the job.
3182 */
3190 }
3195 }
3197 }
3203 }
3206 }
3207 #endif
3209 #ifndef SQLITE_OMIT_SUBQUERY
3210 /*
3211 ** Argument pExpr is an (?, ?...) IN(...) expression. This
3212 ** function allocates and returns a nul-terminated string containing
3213 ** the affinities to be used for each column of the comparison.
3214 **
3215 ** It is the responsibility of the caller to ensure that the returned
3216 ** string is eventually freed using sqlite3DbFree().
3217 */
3235 }
3236 }
3238 }
3240 }
3241 #endif
3243 #ifndef SQLITE_OMIT_SUBQUERY
3244 /*
3245 ** Load the Parse object passed as the first argument with an error
3246 ** message of the form:
3247 **
3248 ** "sub-select returns N columns - expected M"
3249 */
3254 }
3255 }
3256 #endif
3258 /*
3259 ** Expression pExpr is a vector that has been used in a context where
3260 ** it is not permitted. If pExpr is a sub-select vector, this routine
3261 ** loads the Parse object with a message of the form:
3262 **
3263 ** "sub-select returns N columns - expected 1"
3264 **
3265 ** Or, if it is a regular scalar vector:
3266 **
3267 ** "row value misused"
3268 */
3270 #ifndef SQLITE_OMIT_SUBQUERY
3274 #endif
3275 {
3277 }
3278 }
3280 #ifndef SQLITE_OMIT_SUBQUERY
3281 /*
3282 ** Generate code that will construct an ephemeral table containing all terms
3283 ** in the RHS of an IN operator. The IN operator can be in either of two
3284 ** forms:
3285 **
3286 ** x IN (4,5,11) -- IN operator with list on right-hand side
3287 ** x IN (SELECT a FROM b) -- IN operator with subquery on the right
3288 **
3289 ** The pExpr parameter is the IN operator. The cursor number for the
3290 ** constructed ephemeral table is returned. The first time the ephemeral
3291 ** table is computed, the cursor number is also stored in pExpr->iTable,
3292 ** however the cursor number returned might not be the same, as it might
3293 ** have been duplicated using OP_OpenDup.
3294 **
3295 ** If the LHS expression ("x" in the examples) is a column value, or
3296 ** the SELECT statement returns a column value, then the affinity of that
3297 ** column is used to build the index keys. If both 'x' and the
3298 ** SELECT... statement are columns, then numeric affinity is used
3299 ** if either column has NUMERIC or INTEGER affinity. If neither
3300 ** 'x' nor the SELECT... statement are columns, then numeric affinity
3301 ** is used.
3302 */
3307 ){
3318 /* The evaluation of the IN must be repeated every time it
3319 ** is encountered if any of the following is true:
3320 **
3321 ** * The right-hand side is a correlated subquery
3322 ** * The right-hand side is an expression list containing variables
3323 ** * We are inside a trigger
3324 **
3325 ** If all of the above are false, then we can compute the RHS just once
3326 ** and reuse it many names.
3327 */
3329 /* Reuse of the RHS is allowed */
3330 /* If this routine has already been coded, but the previous code
3331 ** might not have been invoked yet, so invoke it now as a subroutine.
3332 */
3338 }
3346 }
3348 /* Begin coding the subroutine */
3357 }
3359 /* Check to see if this is a vector IN operator */
3363 /* Construct the ephemeral table that will contain the content of
3364 ** RHS of the IN operator.
3365 */
3368 #ifdef SQLITE_ENABLE_EXPLAIN_COMMENTS
3373 }
3374 #endif
3378 /* Case 1: expr IN (SELECT ...)
3379 **
3380 ** Generate code to write the results of the select into the temporary
3381 ** table allocated and opened above.
3382 */
3388 ));
3389 /* If the LHS and RHS of the IN operator do not match, that
3390 ** error will have been caught long before we reach this point. */
3393 SelectDest dest;
3408 }
3417 );
3418 }
3419 }
3421 /* Case 2: expr IN (exprlist)
3422 **
3423 ** For each expression, build an index key from the evaluation and
3424 ** store it in the temporary table. If <expr> is a column, then use
3425 ** that columns affinity when building index keys. If <expr> is not
3426 ** a column, use numeric affinity.
3427 */
3438 }
3442 }
3444 /* Loop through each expression in <exprlist>. */
3450 /* If the expression is not constant then we will need to
3451 ** disable the test that was generated above that makes sure
3452 ** this code only executes once. Because for a non-constant
3453 ** expression we need to rerun this code each time.
3454 */
3460 }
3462 /* Evaluate the expression and insert it into the temp table */
3466 }
3469 }
3472 }
3476 /* Subroutine return */
3484 }
3485 }
3488 /*
3489 ** Generate code for scalar subqueries used as a subquery expression
3490 ** or EXISTS operator:
3491 **
3492 ** (SELECT a FROM b) -- subquery
3493 ** EXISTS (SELECT a FROM b) -- EXISTS subquery
3494 **
3495 ** The pExpr parameter is the SELECT or EXISTS operator to be coded.
3496 **
3497 ** Return the register that holds the result. For a multi-column SELECT,
3498 ** the result is stored in a contiguous array of registers and the
3499 ** return value is the register of the left-most result column.
3500 ** Return 0 if an error occurs.
3501 */
3502 #ifndef SQLITE_OMIT_SUBQUERY
3510 #ifdef SQLITE_ENABLE_STMT_SCANSTATUS
3512 #endif
3523 /* If this routine has already been coded, then invoke it as a
3524 ** subroutine. */
3531 }
3533 /* Begin coding the subroutine */
3541 /* The evaluation of the EXISTS/SELECT must be repeated every time it
3542 ** is encountered if any of the following is true:
3543 **
3544 ** * The right-hand side is a correlated subquery
3545 ** * The right-hand side is an expression list containing variables
3546 ** * We are inside a trigger
3547 **
3548 ** If all of the above are false, then we can run this code just once
3549 ** save the results, and reuse the same result on subsequent invocations.
3550 */
3553 }
3555 /* For a SELECT, generate code to put the values for all columns of
3556 ** the first row into an array of registers and return the index of
3557 ** the first register.
3558 **
3559 ** If this is an EXISTS, write an integer 0 (not exists) or 1 (exists)
3560 ** into a register and return that register number.
3561 **
3562 ** In both cases, the query is augmented with "LIMIT 1". Any
3563 ** preexisting limit is discarded in place of the new LIMIT 1.
3564 */
3581 }
3583 /* The subquery already has a limit. If the pre-existing limit is X
3584 ** then make the new limit X<>0 so that the new limit is either 1 or 0 */
3591 }
3595 /* If there is no pre-existing limit add a limit of 1 */
3598 }
3604 }
3609 }
3612 /* Subroutine return */
3621 }
3624 #ifndef SQLITE_OMIT_SUBQUERY
3625 /*
3626 ** Expr pIn is an IN(...) expression. This function checks that the
3627 ** sub-select on the RHS of the IN() operator has the same number of
3628 ** columns as the vector on the LHS. Or, if the RHS of the IN() is not
3629 ** a sub-query, that the LHS is a vector of size 1.
3630 */
3637 }
3641 }
3643 }
3644 #endif
3646 #ifndef SQLITE_OMIT_SUBQUERY
3647 /*
3648 ** Generate code for an IN expression.
3649 **
3650 ** x IN (SELECT ...)
3651 ** x IN (value, value, ...)
3652 **
3653 ** The left-hand side (LHS) is a scalar or vector expression. The
3654 ** right-hand side (RHS) is an array of zero or more scalar values, or a
3655 ** subquery. If the RHS is a subquery, the number of result columns must
3656 ** match the number of columns in the vector on the LHS. If the RHS is
3657 ** a list of values, the LHS must be a scalar.
3658 **
3659 ** The IN operator is true if the LHS value is contained within the RHS.
3660 ** The result is false if the LHS is definitely not in the RHS. The
3661 ** result is NULL if the presence of the LHS in the RHS cannot be
3662 ** determined due to NULLs.
3663 **
3664 ** This routine generates code that jumps to destIfFalse if the LHS is not
3665 ** contained within the RHS. If due to NULLs we cannot determine if the LHS
3666 ** is contained in the RHS then jump to destIfNull. If the LHS is contained
3667 ** within the RHS then fall through.
3668 **
3669 ** See the separate in-operator.md documentation file in the canonical
3670 ** SQLite source tree for additional information.
3671 */
3677 ){
3704 );
3707 /* Attempt to compute the RHS. After this step, if anything other than
3708 ** IN_INDEX_NOOP is returned, the table opened with cursor iTab
3709 ** contains the values that make up the RHS. If IN_INDEX_NOOP is returned,
3710 ** the RHS has not yet been coded. */
3721 );
3722 #ifdef SQLITE_DEBUG
3723 /* Confirm that aiMap[] contains nVector integer values between 0 and
3724 ** nVector-1. */
3729 }
3730 #endif
3732 /* Code the LHS, the <expr> from "<expr> IN (...)". If the LHS is a
3733 ** vector, then it is stored in an array of nVector registers starting
3734 ** at r1.
3735 **
3736 ** sqlite3FindInIndex() might have reordered the fields of the LHS vector
3737 ** so that the fields are in the same order as an existing index. The
3738 ** aiMap[] array contains a mapping from the original LHS field order to
3739 ** the field order that matches the RHS index.
3740 **
3741 ** Avoid factoring the LHS of the IN(...) expression out of the loop,
3742 ** even if it is constant, as OP_Affinity may be used on the register
3743 ** by code generated below. */
3750 /* LHS fields are not reordered */
3753 /* Need to reorder the LHS fields according to aiMap */
3757 }
3758 }
3760 /* If sqlite3FindInIndex() did not find or create an index that is
3761 ** suitable for evaluating the IN operator, then evaluate using a
3762 ** sequence of comparisons.
3763 **
3764 ** This is step (1) in the in-operator.md optimized algorithm.
3765 */
3779 }
3784 }
3803 }
3804 }
3808 }
3812 }
3814 /* Step 2: Check to see if the LHS contains any NULL columns. If the
3815 ** LHS does contain NULLs then the result must be either FALSE or NULL.
3816 ** We will then skip the binary search of the RHS.
3817 */
3822 }
3829 }
3830 }
3832 /* Step 3. The LHS is now known to be non-NULL. Do the binary search
3833 ** of the RHS using the LHS as a probe. If found, the result is
3834 ** true.
3835 */
3837 /* In this case, the RHS is the ROWID of table b-tree and so we also
3838 ** know that the RHS is non-NULL. Hence, we combine steps 3 and 4
3839 ** into a single opcode. */
3846 /* Combine Step 3 and Step 5 into a single opcode */
3850 }
3851 /* Ordinary Step 3, for the case where FALSE and NULL are distinct */
3854 }
3856 /* Step 4. If the RHS is known to be non-NULL and we did not find
3857 ** an match on the search above, then the result must be FALSE.
3858 */
3862 }
3864 /* Step 5. If we do not care about the difference between NULL and
3865 ** FALSE, then just return false.
3866 */
3869 /* Step 6: Loop through rows of the RHS. Compare each row to the LHS.
3870 ** If any comparison is NULL, then the result is NULL. If all
3871 ** comparisons are FALSE then the final result is FALSE.
3872 **
3873 ** For a scalar LHS, it is sufficient to check just the first row
3874 ** of the RHS.
3875 */
3882 /* For nVector==1, combine steps 6 and 7 by immediately returning
3883 ** FALSE if the first comparison is not NULL */
3885 }
3897 }
3904 /* Step 7: If we reach this point, we know that the result must
3905 ** be false. */
3907 }
3909 /* Jumps here in order to return true. */
3912 sqlite3ExprCodeIN_finished:
3915 sqlite3ExprCodeIN_oom_error:
3918 }
3921 #ifndef SQLITE_OMIT_FLOATING_POINT
3922 /*
3923 ** Generate an instruction that will put the floating point
3924 ** value described by z[0..n-1] into register iMem.
3925 **
3926 ** The z[] string will probably not be zero-terminated. But the
3927 ** z[n] character is guaranteed to be something that does not look
3928 ** like the continuation of the number.
3929 */
3937 }
3938 }
3939 #endif
3942 /*
3943 ** Generate an instruction that will put the integer describe by
3944 ** text z[0..n-1] into register iMem.
3945 **
3946 ** Expr.u.zToken is always UTF8 and zero-terminated.
3947 */
3957 i64 value;
3962 #ifdef SQLITE_OMIT_FLOATING_POINT
3964 #else
3965 #ifndef SQLITE_OMIT_HEX_INTEGER
3970 #endif
3971 {
3973 }
3974 #endif
3978 }
3979 }
3980 }
3983 /* Generate code that will load into register regOut a value that is
3984 ** appropriate for the iIdxCol-th column of index pIdx.
3985 */
3992 ){
4003 }
4004 }
4006 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
4007 /*
4008 ** Generate code that will compute the value of generated column pCol
4009 ** and store the result in register regOut
4010 */
4016 ){
4026 }
4030 }
4033 }
4036 /*
4037 ** Generate code to extract the value of the iCol-th column of a table.
4038 */
4045 ){
4059 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
4072 }
4074 #endif
4083 }
4086 }
4087 }
4089 /*
4090 ** Generate code that will extract the iColumn-th column from
4091 ** table pTab and store the column value in register iReg.
4092 **
4093 ** There must be an open cursor to pTab in iTable when this routine
4094 ** is called. If iColumn<0 then code is generated that extracts the rowid.
4095 */
4102 u8 p5 /* P5 value for OP_Column + FLAGS */
4103 ){
4112 }
4114 }
4116 /*
4117 ** Generate code to move content from registers iFrom...iFrom+nReg-1
4118 ** over to iTo..iTo+nReg-1.
4119 */
4122 }
4124 /*
4125 ** Convert a scalar expression node to a TK_REGISTER referencing
4126 ** register iReg. The caller must ensure that iReg already contains
4127 ** the correct value for the expression.
4128 */
4136 }
4138 /*
4139 ** Evaluate an expression (either a vector or a scalar expression) and store
4140 ** the result in contiguous temporary registers. Return the index of
4141 ** the first register used to store the result.
4142 **
4143 ** If the returned result register is a temporary scalar, then also write
4144 ** that register number into *piFreeable. If the returned result register
4145 ** is not a temporary or if the expression is a vector set *piFreeable
4146 ** to 0.
4147 */
4156 #if SQLITE_OMIT_SUBQUERY
4158 #else
4160 #endif
4168 }
4169 }
4170 }
4172 }
4174 /*
4175 ** If the last opcode is a OP_Copy, then set the do-not-merge flag (p5)
4176 ** so that a subsequent copy will not be merged into this one.
4177 */
4181 }
4182 }
4184 /*
4185 ** Generate code to implement special SQL functions that are implemented
4186 ** in-line rather than by using the usual callbacks.
4187 */
4193 ){
4202 /* Attempt a direct implementation of the built-in COALESCE() and
4203 ** IFNULL() functions. This avoids unnecessary evaluation of
4204 ** arguments past the first non-NULL argument.
4205 */
4214 }
4218 }
4220 Expr caseExpr;
4225 }
4226 #ifdef SQLITE_ENABLE_OFFSET_SQL_FUNC
4233 }
4235 }
4236 #endif
4238 /* The UNLIKELY() function is a no-op. The result is the value
4239 ** of the first argument.
4240 */
4244 }
4246 /***********************************************************************
4247 ** Test-only SQL functions that are only usable if enabled
4248 ** via SQLITE_TESTCTRL_INTERNAL_FUNCTIONS
4249 */
4250 #if !defined(SQLITE_UNTESTABLE)
4252 /* Compare two expressions using sqlite3ExprCompare() */
4256 target);
4258 }
4261 /* Compare two expressions using sqlite3ExprImpliesExpr() */
4265 target);
4267 }
4270 /* Result of sqlite3ExprImpliesNonNullRow() */
4277 target);
4280 }
4282 }
4285 /* The AFFINITY() function evaluates to a string that describes
4286 ** the type affinity of the argument. This is used for testing of
4287 ** the SQLite type logic.
4288 */
4299 }
4301 }
4303 }
4305 /*
4306 ** Check to see if pExpr is one of the indexed expressions on pParse->pIdxEpr.
4307 ** If it is, then resolve the expression by reading from the index and
4308 ** return the register into which the value has been read. If pExpr is
4309 ** not an indexed expression, then return negative.
4310 */
4315 ){
4319 u8 exprAff;
4325 }
4332 ){
4333 /* Affinity mismatch on a generated column */
4335 }
4340 /* If the index is on a NULL row due to an outer join, then we
4341 ** cannot extract the value from the index. The value must be
4342 ** computed using the original expression. */
4357 }
4359 }
4361 }
4364 /*
4365 ** Expresion pExpr is guaranteed to be a TK_COLUMN or equivalent. This
4366 ** function checks the Parse.pIdxPartExpr list to see if this column
4367 ** can be replaced with a constant value. If so, it generates code to
4368 ** put the constant value in a register (ideally, but not necessarily,
4369 ** register iTarget) and returns the register number.
4370 **
4371 ** Or, if the TK_COLUMN cannot be replaced by a constant, zero is
4372 ** returned.
4373 */
4384 }
4391 }
4393 }
4394 }
4396 }
4399 /*
4400 ** Generate code into the current Vdbe to evaluate the given
4401 ** expression. Attempt to store the results in register "target".
4402 ** Return the register where results are stored.
4403 **
4404 ** With this routine, there is no guarantee that results will
4405 ** be stored in target. The result might be stored in some other
4406 ** register if it is convenient to do so. The calling function
4407 ** must check the return code and move the results to the desired
4408 ** register.
4409 */
4423 expr_code_doover:
4429 ){
4434 }
4443 /* Happens when the left table of a RIGHT JOIN is null and
4444 ** is using an expression index */
4446 #ifdef SQLITE_VDBE_COVERAGE
4447 /* Verify that the OP_Null above is exercised by tests
4448 ** tag-20230325-2 */
4451 #endif
4453 }
4462 /* No comment added */
4470 }
4471 }
4474 /* This case happens when the argument to an aggregate function
4475 ** is rewritten by aggregateConvertIndexedExprRefToColumn() */
4478 }
4479 /* Otherwise, fall thru into the TK_COLUMN case */
4480 /* no break */ deliberate_fall_through
4481 }
4486 /* This COLUMN expression is really a constant due to WHERE clause
4487 ** constraints, and that constant is coded by the pExpr->pLeft
4488 ** expression. However, make sure the constant has the correct
4489 ** datatype by applying the Affinity of the table column to the
4490 ** constant.
4491 */
4503 }
4505 }
4508 /* Other columns in the same row for CHECK constraints or
4509 ** generated columns or for inserting into partial index.
4510 ** The row is unpacked into registers beginning at
4511 ** 0-(pParse->iSelfTab). The rowid (if any) is in a register
4512 ** immediately prior to the first column.
4513 */
4525 }
4529 #ifndef SQLITE_OMIT_GENERATED_COLUMNS
4535 }
4539 }
4550 }
4552 /* Coding an expression that is part of an index where column names
4553 ** in the index refer to the table to which the index belongs */
4555 }
4556 }
4559 ){
4561 }
4568 }
4572 }
4576 }
4577 #ifndef SQLITE_OMIT_FLOATING_POINT
4582 }
4583 #endif
4588 }
4590 /* Make NULL the default case so that if a bug causes an illegal
4591 ** Expr node to be passed into this function, it will be handled
4592 ** sanely and not crash. But keep the assert() to bring the problem
4593 ** to the attention of the developers. */
4597 }
4598 #ifndef SQLITE_OMIT_BLOB_LITERAL
4612 }
4613 #endif
4624 }
4626 }
4629 }
4630 #ifndef SQLITE_OMIT_CAST
4632 /* Expressions of the form: CAST(pLeft AS token) */
4639 }
4645 /* fall-through */
4672 }
4675 }
4677 }
4707 }
4714 #ifndef SQLITE_OMIT_FLOATING_POINT
4719 #endif
4729 }
4731 }
4740 }
4752 }
4767 }
4773 ){
4778 }
4780 }
4792 #ifndef SQLITE_OMIT_WINDOWFUNC
4795 }
4796 #endif
4799 /* SQL functions can be expensive. So try to avoid running them
4800 ** multiple times if we know they always give the same result */
4802 }
4810 #ifdef SQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
4813 }
4814 #endif
4818 }
4826 }
4832 }
4835 }
4836 }
4843 }
4845 /* For length() and typeof() and octet_length() functions,
4846 ** set the P5 parameter to the OP_Column opcode to OPFLAG_LENGTHARG
4847 ** or OPFLAG_TYPEOFARG or OPFLAG_BYTELENARG respectively, to avoid
4848 ** unnecessary data loading.
4849 */
4851 u8 exprOp;
4864 }
4865 }
4870 }
4871 #ifndef SQLITE_OMIT_VIRTUALTABLE
4872 /* Possibly overload the function if the first argument is
4873 ** a virtual table column.
4874 **
4875 ** For infix functions (LIKE, GLOB, REGEXP, and MATCH) use the
4876 ** second argument, not the first, as the argument to test to
4877 ** see if it is a column in a virtual table. This is done because
4878 ** the left operand of infix functions (the operand we want to
4879 ** control overloading) ends up as the second argument to the
4880 ** function. The expression "A glob B" is equivalent to
4881 ** "glob(B,A). We want to use the A in "A glob B" to test
4882 ** for function overloading. But we use the B term in "glob(B,A)".
4883 */
4888 }
4889 #endif
4893 }
4901 }
4902 }
4904 }
4905 #ifndef SQLITE_OMIT_SUBQUERY
4916 ){
4920 }
4922 }
4929 }
4935 }
4937 }
4948 }
4952 /*
4953 ** x BETWEEN y AND z
4954 **
4955 ** This is equivalent to
4956 **
4957 ** x>=y AND x<=z
4958 **
4959 ** X is stored in pExpr->pLeft.
4960 ** Y is stored in pExpr->pList->a[0].pExpr.
4961 ** Z is stored in pExpr->pList->a[1].pExpr.
4962 */
4966 }
4969 /* A TK_COLLATE Expr node without the EP_Collate tag is a so-called
4970 ** "SOFT-COLLATE" that is added to constraints that are pushed down
4971 ** from outer queries into sub-queries by the push-down optimization.
4972 ** Clear subtypes as subtypes may not cross a subquery boundary.
4973 */
4981 }
4982 }
4987 }
4990 /* If the opcode is TK_TRIGGER, then the expression is a reference
4991 ** to a column in the new.* or old.* pseudo-tables available to
4992 ** trigger programs. In this case Expr.iTable is set to 1 for the
4993 ** new.* pseudo-table, or 0 for the old.* pseudo-table. Expr.iColumn
4994 ** is set to the column of the pseudo-table to read, or to -1 to
4995 ** read the rowid field.
4996 **
4997 ** The expression is implemented using an OP_Param opcode. The p1
4998 ** parameter is set to 0 for an old.rowid reference, or to (i+1)
4999 ** to reference another column of the old.* pseudo-table, where
5000 ** i is the index of the column. For a new.rowid reference, p1 is
5001 ** set to (n+1), where n is the number of columns in each pseudo-table.
5002 ** For a reference to any other column in the new.* pseudo-table, p1
5003 ** is set to (n+2+i), where n and i are as defined previously. For
5004 ** example, if the table on which triggers are being fired is
5005 ** declared as:
5006 **
5007 ** CREATE TABLE t1(a, b);
5008 **
5009 ** Then p1 is interpreted as follows:
5010 **
5011 ** p1==0 -> old.rowid p1==3 -> new.rowid
5012 ** p1==1 -> old.a p1==4 -> new.a
5013 ** p1==2 -> old.b p1==5 -> new.b
5014 */
5034 ));
5036 #ifndef SQLITE_OMIT_FLOATING_POINT
5037 /* If the column has REAL affinity, it may currently be stored as an
5038 ** integer. Use OP_RealAffinity to make sure it is really real.
5039 **
5040 ** EVIDENCE-OF: R-60985-57662 SQLite will convert the value back to
5041 ** floating point when extracting it from the record. */
5044 }
5045 #endif
5047 }
5052 }
5054 /* TK_IF_NULL_ROW Expr nodes are inserted ahead of expressions
5055 ** that derive from the right-hand table of a LEFT JOIN. The
5056 ** Expr.iTable value is the table number for the right-hand table.
5057 ** The expression is only evaluated if that table is not currently
5058 ** on a LEFT JOIN NULL row.
5059 */
5069 }
5073 target);
5076 }
5077 }
5079 /* The OP_IfNullRow opcode above can overwrite the result register with
5080 ** NULL. So we have to ensure that the result register is not a value
5081 ** that is suppose to be a constant. Two defenses are needed:
5082 ** (1) Temporarily disable factoring of constant expressions
5083 ** (2) Make sure the computed value really is stored in register
5084 ** "target" and not someplace else.
5085 */
5092 }
5094 /*
5095 ** Form A:
5096 ** CASE x WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
5097 **
5098 ** Form B:
5099 ** CASE WHEN e1 THEN r1 WHEN e2 THEN r2 ... WHEN eN THEN rN ELSE y END
5100 **
5101 ** Form A is can be transformed into the equivalent form B as follows:
5102 ** CASE WHEN x=e1 THEN r1 WHEN x=e2 THEN r2 ...
5103 ** WHEN x=eN THEN rN ELSE y END
5104 **
5105 ** X (if it exists) is in pExpr->pLeft.
5106 ** Y is in the last element of pExpr->x.pList if pExpr->x.pList->nExpr is
5107 ** odd. The Y is also optional. If the number of elements in x.pList
5108 ** is even, then Y is omitted and the "otherwise" result is NULL.
5109 ** Ei is in pExpr->pList->a[i*2] and Ri is pExpr->pList->a[i*2+1].
5110 **
5111 ** The result of the expression is the Ri for the first matching Ei,
5112 ** or if there is no matching Ei, the ELSE term Y, or if there is
5113 ** no ELSE term, NULL.
5114 */
5139 }
5147 /* Ticket b351d95f9cd5ef17e9d9dbae18f5ca8611190001:
5148 ** The value in regFree1 might get SCopy-ed into the file result.
5149 ** So make sure that the regFree1 register is not reused for other
5150 ** purposes and possibly overwritten. */
5152 }
5159 }
5167 }
5172 }
5177 }
5178 #ifndef SQLITE_OMIT_TRIGGER
5184 );
5189 }
5192 }
5202 }
5205 }
5206 #endif
5207 }
5211 }
5213 /*
5214 ** Generate code that will evaluate expression pExpr just one time
5215 ** per prepared statement execution.
5216 **
5217 ** If the expression uses functions (that might throw an exception) then
5218 ** guard them with an OP_Once opcode to ensure that the code is only executed
5219 ** once. If no functions are involved, then factor the code out and put it at
5220 ** the end of the prepared statement in the initialization section.
5221 **
5222 ** If regDest>0 then the result is always stored in that register and the
5223 ** result is not reusable. If regDest<0 then this routine is free to
5224 ** store the value wherever it wants. The register where the expression
5225 ** is stored is returned. When regDest<0, two identical expressions might
5226 ** code to the same register, if they do not contain function calls and hence
5227 ** are factored out into the initialization section at the end of the
5228 ** prepared statement.
5229 */
5234 ){
5245 ){
5247 }
5248 }
5249 }
5260 }
5271 }
5273 }
5275 }
5277 /*
5278 ** Generate code to evaluate an expression and store the results
5279 ** into a register. Return the register number where the results
5280 ** are stored.
5281 **
5282 ** If the register is a temporary register that can be deallocated,
5283 ** then write its number into *pReg. If the result register is not
5284 ** a temporary, then set *pReg to zero.
5285 **
5286 ** If pExpr is a constant, then this routine might generate this
5287 ** code to fill the register in the initialization section of the
5288 ** VDBE program, in order to factor it out of the evaluation loop.
5289 */
5297 ){
5308 }
5309 }
5311 }
5313 /*
5314 ** Generate code that will evaluate expression pExpr and store the
5315 ** results in register target. The results are guaranteed to appear
5316 ** in register target.
5317 */
5327 u8 op;
5332 ){
5336 }
5338 }
5339 }
5341 /*
5342 ** Make a transient copy of expression pExpr and then code it using
5343 ** sqlite3ExprCode(). This routine works just like sqlite3ExprCode()
5344 ** except that the input expression is guaranteed to be unchanged.
5345 */
5351 }
5353 /*
5354 ** Generate code that will evaluate expression pExpr and store the
5355 ** results in register target. The results are guaranteed to appear
5356 ** in register target. If the expression is constant, then this routine
5357 ** might choose to code the expression at initialization time.
5358 */
5364 }
5365 }
5367 /*
5368 ** Generate code that pushes the value of every element of the given
5369 ** expression list into a sequence of registers beginning at target.
5370 **
5371 ** Return the number of elements evaluated. The number returned will
5372 ** usually be pList->nExpr but might be reduced if SQLITE_ECEL_OMITREF
5373 ** is defined.
5374 **
5375 ** The SQLITE_ECEL_DUP flag prevents the arguments from being
5376 ** filled using OP_SCopy. OP_Copy must be used instead.
5377 **
5378 ** The SQLITE_ECEL_FACTOR argument allows constant arguments to be
5379 ** factored out into initialization code.
5380 **
5381 ** The SQLITE_ECEL_REF flag means that expressions in the list with
5382 ** ExprList.a[].u.x.iOrderByCol>0 have already been evaluated and stored
5383 ** in registers at srcReg, and so the value can be copied from there.
5384 ** If SQLITE_ECEL_OMITREF is also set, then the values with u.x.iOrderByCol>0
5385 ** are simply omitted rather than being copied from srcReg.
5386 */
5392 u8 flags /* SQLITE_ECEL_* flags */
5393 ){
5405 #ifdef SQLITE_ENABLE_SORTER_REFERENCES
5407 i--;
5408 n--;
5410 #endif
5413 i--;
5414 n--;
5417 }
5420 ){
5431 ){
5435 }
5436 }
5437 }
5438 }
5440 }
5442 /*
5443 ** Generate code for a BETWEEN operator.
5444 **
5445 ** x BETWEEN y AND z
5446 **
5447 ** The above is equivalent to
5448 **
5449 ** x>=y AND x<=z
5450 **
5451 ** Code it as such, taking care to do the common subexpression
5452 ** elimination of x.
5453 **
5454 ** The xJumpIf parameter determines details:
5455 **
5456 ** NULL: Store the boolean result in reg[dest]
5457 ** sqlite3ExprIfTrue: Jump to dest if true
5458 ** sqlite3ExprIfFalse: Jump to dest if false
5459 **
5460 ** The jumpIfNull parameter is ignored if xJumpIf is NULL.
5461 */
5468 ){
5496 /* Mark the expression is being from the ON or USING clause of a join
5497 ** so that the sqlite3ExprCodeTarget() routine will not attempt to move
5498 ** it into the Parse.pConstExpr list. We should use a new bit for this,
5499 ** for clarity, but we are out of bits in the Expr.flags field so we
5500 ** have to reuse the EP_OuterON bit. Bummer. */
5503 }
5505 }
5508 /* Ensure adequate test coverage */
5518 }
5520 /*
5521 ** Generate code for a boolean expression such that a jump is made
5522 ** to the label "dest" if the expression is true but execution
5523 ** continues straight thru if the expression is false.
5524 **
5525 ** If the expression evaluates to NULL (neither true nor false), then
5526 ** take the jump if the jumpIfNull flag is SQLITE_JUMPIFNULL.
5527 **
5528 ** This code depends on the fact that certain token values (ex: TK_EQ)
5529 ** are the same as opcode values (ex: OP_Eq) that implement the corresponding
5530 ** operation. Special comments in vdbe.c and the mkopcodeh.awk script in
5531 ** the make process cause these values to align. Assert()s in the code
5532 ** below verify that the numbers are aligned correctly.
5533 */
5563 }
5565 }
5570 }
5585 }
5587 }
5594 /* no break */ deliberate_fall_through
5620 }
5632 }
5637 }
5638 #ifndef SQLITE_OMIT_SUBQUERY
5646 }
5647 #endif
5649 default_expr:
5653 /* No-op */
5660 }
5662 }
5663 }
5666 }
5668 /*
5669 ** Generate code for a boolean expression such that a jump is made
5670 ** to the label "dest" if the expression is false but execution
5671 ** continues straight thru if the expression is true.
5672 **
5673 ** If the expression evaluates to NULL (neither true nor false) then
5674 ** jump if jumpIfNull is SQLITE_JUMPIFNULL or fall through if jumpIfNull
5675 ** is 0.
5676 */
5689 /* The value of pExpr->op and op are related as follows:
5690 **
5691 ** pExpr->op op
5692 ** --------- ----------
5693 ** TK_ISNULL OP_NotNull
5694 ** TK_NOTNULL OP_IsNull
5695 ** TK_NE OP_Eq
5696 ** TK_EQ OP_Ne
5697 ** TK_GT OP_Le
5698 ** TK_LE OP_Gt
5699 ** TK_GE OP_Lt
5700 ** TK_LT OP_Ge
5701 **
5702 ** For other values of pExpr->op, op is undefined and unused.
5703 ** The value of TK_ and OP_ constants are arranged such that we
5704 ** can compute the mapping above using the following expression.
5705 ** Assert()s verify that the computation is correct.
5706 */
5709 /* Verify correct alignment of TK_ and OP_ constants
5710 */
5737 }
5739 }
5744 }
5754 /* IS TRUE and IS NOT FALSE */
5759 /* IS FALSE and IS NOT TRUE */
5762 }
5764 }
5771 /* no break */ deliberate_fall_through
5797 }
5807 }
5812 }
5813 #ifndef SQLITE_OMIT_SUBQUERY
5821 }
5823 }
5824 #endif
5826 default_expr:
5830 /* no-op */
5837 }
5839 }
5840 }
5843 }
5845 /*
5846 ** Like sqlite3ExprIfFalse() except that a copy is made of pExpr before
5847 ** code generation, and that copy is deleted after code generation. This
5848 ** ensures that the original pExpr is unchanged.
5849 */
5855 }
5857 }
5859 /*
5860 ** Expression pVar is guaranteed to be an SQL variable. pExpr may be any
5861 ** type of expression.
5862 **
5863 ** If pExpr is a simple SQL value - an integer, real, string, blob
5864 ** or NULL value - then the VDBE currently being prepared is configured
5865 ** to re-prepare each time a new value is bound to variable pVar.
5866 **
5867 ** Additionally, if pExpr is a simple SQL value and the value is the
5868 ** same as that currently bound to variable pVar, non-zero is returned.
5869 ** Otherwise, if the values are not the same or if pExpr is not a simple
5870 ** SQL value, zero is returned.
5871 */
5876 ){
5889 }
5891 }
5894 }
5897 }
5899 /*
5900 ** Do a deep comparison of two expression trees. Return 0 if the two
5901 ** expressions are completely identical. Return 1 if they differ only
5902 ** by a COLLATE operator at the top level. Return 2 if there are differences
5903 ** other than the top-level COLLATE operator.
5904 **
5905 ** If any subelement of pB has Expr.iTable==(-1) then it is allowed
5906 ** to compare equal to an equivalent element in pA with Expr.iTable==iTab.
5907 **
5908 ** The pA side might be using TK_REGISTER. If that is the case and pB is
5909 ** not using TK_REGISTER but is otherwise equivalent, then still return 0.
5910 **
5911 ** Sometimes this routine will return 2 even if the two expressions
5912 ** really are equivalent. If we cannot prove that the expressions are
5913 ** identical, we return 2 just to be safe. So if this routine
5914 ** returns 2, then you do not really know for certain if the two
5915 ** expressions are the same. But if you get a 0 or 1 return, then you
5916 ** can be sure the expressions are the same. In the places where
5917 ** this routine is used, it does not hurt to get an extra 2 - that
5918 ** just might result in some slightly slower code. But returning
5919 ** an incorrect 0 or 1 could lead to a malfunction.
5920 **
5921 ** If pParse is not NULL then TK_VARIABLE terms in pA with bindings in
5922 ** pParse->pReprepare can be matched against literals in pB. The
5923 ** pParse->pVdbe->expmask bitmask is updated for each variable referenced.
5924 ** If pParse is NULL (the normal case) then any TK_VARIABLE term in
5925 ** Argument pParse should normally be NULL. If it is not NULL and pA or
5926 ** pB causes a return value of 2.
5927 */
5932 int iTab
5933 ){
5934 u32 combinedFlags;
5937 }
5940 }
5945 }
5947 }
5951 }
5954 }
5957 ){
5958 /* fall through */
5961 }
5962 }
5968 #ifndef SQLITE_OMIT_WINDOWFUNC
5972 }
5976 }
5977 }
5978 #endif
5988 ){
5990 }
5991 }
6003 ){
6008 }
6009 }
6010 }
6012 }
6014 /*
6015 ** Compare two ExprList objects. Return 0 if they are identical, 1
6016 ** if they are certainly different, or 2 if it is not possible to
6017 ** determine if they are identical or not.
6018 **
6019 ** If any subelement of pB has Expr.iTable==(-1) then it is allowed
6020 ** to compare equal to an equivalent element in pA with Expr.iTable==iTab.
6021 **
6022 ** This routine might return non-zero for equivalent ExprLists. The
6023 ** only consequence will be disabled optimizations. But this routine
6024 ** must never return 0 if the two ExprList objects are different, or
6025 ** a malfunction will result.
6026 **
6027 ** Two NULL pointers are considered to be the same. But a NULL pointer
6028 ** always differs from a non-NULL pointer.
6029 */
6041 }
6043 }
6045 /*
6046 ** Like sqlite3ExprCompare() except COLLATE operators at the top-level
6047 ** are ignored.
6048 */
6053 iTab);
6054 }
6056 /*
6057 ** Return non-zero if Expr p can only be true if pNN is not NULL.
6058 **
6059 ** Or if seenNot is true, return non-zero if Expr p can only be
6060 ** non-NULL if pNN is not NULL
6061 */
6068 ){
6073 }
6079 }
6089 ){
6091 }
6093 }
6107 /* no break */ deliberate_fall_through
6113 /* no break */ deliberate_fall_through
6114 }
6120 }
6125 }
6129 }
6130 }
6132 }
6134 /*
6135 ** Return true if we can prove the pE2 will always be true if pE1 is
6136 ** true. Return false if we cannot complete the proof or if pE2 might
6137 ** be false. Examples:
6138 **
6139 ** pE1: x==5 pE2: x==5 Result: true
6140 ** pE1: x>0 pE2: x==5 Result: false
6141 ** pE1: x=21 pE2: x=21 OR y=43 Result: true
6142 ** pE1: x!=123 pE2: x IS NOT NULL Result: true
6143 ** pE1: x!=?1 pE2: x IS NOT NULL Result: true
6144 ** pE1: x IS NULL pE2: x IS NOT NULL Result: false
6145 ** pE1: x IS ?2 pE2: x IS NOT NULL Result: false
6146 **
6147 ** When comparing TK_COLUMN nodes between pE1 and pE2, if pE2 has
6148 ** Expr.iTable<0 then assume a table number given by iTab.
6149 **
6150 ** If pParse is not NULL, then the values of bound variables in pE1 are
6151 ** compared against literal values in pE2 and pParse->pVdbe->expmask is
6152 ** modified to record which bound variables are referenced. If pParse
6153 ** is NULL, then false will be returned if pE1 contains any bound variables.
6154 **
6155 ** When in doubt, return false. Returning true might give a performance
6156 ** improvement. Returning false might cause a performance reduction, but
6157 ** it will always give the correct answer and is hence always safe.
6158 */
6163 int iTab
6164 ){
6167 }
6171 ){
6173 }
6176 ){
6178 }
6180 }
6182 /* This is a helper function to impliesNotNullRow(). In this routine,
6183 ** set pWalker->eCode to one only if *both* of the input expressions
6184 ** separately have the implies-not-null-row property.
6185 */
6192 }
6193 }
6194 }
6196 /*
6197 ** This is the Expr node callback for sqlite3ExprImpliesNonNullRow().
6198 ** If the expression node requires that the table at pWalker->iCur
6199 ** have one or more non-NULL column, then set pWalker->eCode to 1 and abort.
6200 **
6201 ** pWalker->mWFlags is non-zero if this inquiry is being undertaking on
6202 ** behalf of a RIGHT JOIN (or FULL JOIN). That makes a difference when
6203 ** evaluating terms in the ON clause of an inner join.
6204 **
6205 ** This routine controls an optimization. False positives (setting
6206 ** pWalker->eCode to 1 when it should not be) are deadly, but false-negatives
6207 ** (never setting pWalker->eCode) is a harmless missed optimization.
6208 */
6214 /* If iCur is used in an inner-join ON clause to the left of a
6215 ** RIGHT JOIN, that does *not* mean that the table must be non-null.
6216 ** But it is difficult to check for that condition precisely.
6217 ** To keep things simple, any use of iCur from any inner-join is
6218 ** ignored while attempting to simplify a RIGHT JOIN. */
6220 }
6244 }
6249 /* Both sides of an AND or OR must separately imply non-null-row.
6250 ** Consider these cases:
6251 ** 1. NOT (x AND y)
6252 ** 2. x OR y
6253 ** If only one of x or y is non-null-row, then the overall expression
6254 ** can be true if the other arm is false (case 1) or true (case 2).
6255 */
6262 /* Beware of "x NOT IN ()" and "x NOT IN (SELECT 1 WHERE false)",
6263 ** both of which can be true. But apart from these cases, if
6264 ** the left-hand side of the IN is NULL then the IN itself will be
6265 ** NULL. */
6268 }
6272 /* In "x NOT BETWEEN y AND z" either x must be non-null-row or else
6273 ** both y and z must be non-null row */
6281 /* Virtual tables are allowed to use constraints like x=NULL. So
6282 ** a term of the form x=y does not prove that y is not null if x
6283 ** is the column of a virtual table */
6298 /* The y.pTab=0 assignment in wherecode.c always happens after the
6299 ** impliesNotNullRow() test */
6308 ){
6310 }
6311 /* no break */ deliberate_fall_through
6312 }
6315 }
6316 }
6318 /*
6319 ** Return true (non-zero) if expression p can only be true if at least
6320 ** one column of table iTab is non-null. In other words, return true
6321 ** if expression p will always be NULL or false if every column of iTab
6322 ** is NULL.
6323 **
6324 ** False negatives are acceptable. In other words, it is ok to return
6325 ** zero even if expression p will never be true of every column of iTab
6326 ** is NULL. A false negative is merely a missed optimization opportunity.
6327 **
6328 ** False positives are not allowed, however. A false positive may result
6329 ** in an incorrect answer.
6330 **
6331 ** Terms of p that are marked with EP_OuterON (and hence that come from
6332 ** the ON or USING clauses of OUTER JOINS) are excluded from the analysis.
6333 **
6334 ** This routine is used to check if a LEFT JOIN can be converted into
6335 ** an ordinary JOIN. The p argument is the WHERE clause. If the WHERE
6336 ** clause requires that some column of the right table of the LEFT JOIN
6337 ** be non-NULL, then the LEFT JOIN can be safely converted into an
6338 ** ordinary join.
6339 */
6341 Walker w;
6350 }
6351 }
6360 }
6362 /*
6363 ** An instance of the following structure is used by the tree walker
6364 ** to determine if an expression can be evaluated by reference to the
6365 ** index only, without having to do a search for the corresponding
6366 ** table entry. The IdxCover.pIdx field is the index. IdxCover.iCur
6367 ** is the cursor for the table.
6368 */
6372 };
6374 /*
6375 ** Check to see if there are references to columns in table
6376 ** pWalker->u.pIdxCover->iCur can be satisfied using the index
6377 ** pWalker->u.pIdxCover->pIdx.
6378 */
6383 ){
6386 }
6388 }
6390 /*
6391 ** Determine if an index pIdx on table with cursor iCur contains will
6392 ** the expression pExpr. Return true if the index does cover the
6393 ** expression and false if the pExpr expression references table columns
6394 ** that are not found in the index pIdx.
6395 **
6396 ** An index covering an expression means that the expression can be
6397 ** evaluated using only the index and without having to lookup the
6398 ** corresponding table entry.
6399 */
6404 ){
6405 Walker w;
6414 }
6417 /* Structure used to pass information throughout the Walker in order to
6418 ** implement sqlite3ReferencesSrcList().
6419 */
6425 };
6427 /*
6428 ** Walker SELECT callbacks for sqlite3ReferencesSrcList().
6429 **
6430 ** When entering a new subquery on the pExpr argument, add all FROM clause
6431 ** entries for that subquery to the exclude list.
6432 **
6433 ** When leaving the subquery, remove those entries from the exclude list.
6434 */
6449 }
6452 }
6454 }
6461 }
6462 }
6464 /* This is the Walker EXPR callback for sqlite3ReferencesSrcList().
6465 **
6466 ** Set the 0x01 bit of pWalker->eCode if there is a reference to any
6467 ** of the tables shown in RefSrcList.pRef.
6468 **
6469 ** Set the 0x02 bit of pWalker->eCode if there is a reference to a
6470 ** table is in neither RefSrcList.pRef nor RefSrcList.aiExclude.
6471 */
6475 ){
6484 }
6485 }
6489 }
6490 }
6492 }
6494 /*
6495 ** Check to see if pExpr references any tables in pSrcList.
6496 ** Possible return values:
6497 **
6498 ** 1 pExpr does references a table in pSrcList.
6499 **
6500 ** 0 pExpr references some table that is not defined in either
6501 ** pSrcList or in subqueries of pExpr itself.
6502 **
6503 ** -1 pExpr only references no tables at all, or it only
6504 ** references tables defined in subqueries of pExpr itself.
6505 **
6506 ** As currently used, pExpr is always an aggregate function call. That
6507 ** fact is exploited for efficiency.
6508 */
6510 Walker w;
6529 }
6530 #ifndef SQLITE_OMIT_WINDOWFUNC
6533 }
6534 #endif
6542 }
6543 }
6545 /*
6546 ** This is a Walker expression node callback.
6547 **
6548 ** For Expr nodes that contain pAggInfo pointers, make sure the AggInfo
6549 ** object that is referenced does not refer directly to the Expr. If
6550 ** it does, make a copy. This is done because the pExpr argument is
6551 ** subject to change.
6552 **
6553 ** The copy is scheduled for deletion using the sqlite3ExprDeferredDelete()
6554 ** which builds on the sqlite3ParserAddCleanup() mechanism.
6555 */
6559 ){
6568 ){
6573 }
6574 }
6579 ){
6584 }
6585 }
6586 }
6587 }
6589 }
6591 /*
6592 ** Initialize a Walker object so that will persist AggInfo entries referenced
6593 ** by the tree that is walked.
6594 */
6600 }
6602 /*
6603 ** Add a new element to the pAggInfo->aCol[] array. Return the index of
6604 ** the new element. Return a negative number if malloc fails.
6605 */
6609 db,
6613 &i
6614 );
6616 }
6618 /*
6619 ** Add a new element to the pAggInfo->aFunc[] array. Return the index of
6620 ** the new element. Return a negative number if malloc fails.
6621 */
6625 db,
6629 &i
6630 );
6632 }
6634 /*
6635 ** Search the AggInfo object for an aCol[] entry that has iTable and iColumn.
6636 ** Return the index in aCol[] of the entry that describes that column.
6637 **
6638 ** If no prior entry is found, create a new one and return -1. The
6639 ** new column will have an index of pAggInfo->nColumn-1.
6640 */
6645 ){
6656 ){
6658 }
6659 }
6662 /* OOM on resize */
6665 }
6683 ){
6686 }
6687 }
6688 }
6691 }
6692 fix_up_expr:
6698 }
6700 }
6702 /*
6703 ** This is the xExprCallback for a tree walker. It is used to
6704 ** implement sqlite3ExprAnalyzeAggregates(). See sqlite3ExprAnalyzeAggregates
6705 ** for additional information.
6706 */
6719 Expr tmp;
6727 }
6732 }
6737 /* If we reach this point, it means that expression pExpr can be
6738 ** translated into a reference to an index column as described by
6739 ** pIEpr.
6740 */
6753 }
6760 /* Check to see if the column is in one of the tables in the FROM
6761 ** clause of the aggregate query */
6771 }
6773 }
6778 ){
6779 /* Check to see if pExpr is a duplicate of another aggregate
6780 ** function that is already in the pAggInfo structure
6781 */
6787 }
6788 }
6790 /* pExpr is original. Make a new entry in pAggInfo->aFunc[]
6791 */
6806 ){
6807 /* The NEEDCOLL test above causes any ORDER BY clause on
6808 ** aggregate min() or max() to be ignored. */
6821 ){
6826 }
6831 }
6836 }
6837 }
6838 }
6839 /* Make pExpr point to the appropriate pAggInfo->aFunc[] entry
6840 */
6848 }
6849 }
6850 }
6852 }
6854 /*
6855 ** Analyze the pExpr expression looking for aggregate functions and
6856 ** for variables that need to be added to AggInfo object that pNC->pAggInfo
6857 ** points to. Additional entries are made on the AggInfo object as
6858 ** necessary.
6859 **
6860 ** This routine should only be called after the expression has been
6861 ** analyzed by sqlite3ResolveExprNames().
6862 */
6864 Walker w;
6873 }
6875 /*
6876 ** Call sqlite3ExprAnalyzeAggregates() for every expression in an
6877 ** expression list. Return the number of errors.
6878 **
6879 ** If an error is found, the analysis is cut short.
6880 */
6887 }
6888 }
6889 }
6891 /*
6892 ** Allocate a single new register for use to hold some intermediate result.
6893 */
6897 }
6899 }
6901 /*
6902 ** Deallocate a register, making available for reuse for some other
6903 ** purpose.
6904 */
6910 }
6911 }
6912 }
6914 /*
6915 ** Allocate or deallocate a block of nReg consecutive registers.
6916 */
6928 }
6930 }
6935 }
6940 }
6941 }
6943 /*
6944 ** Mark all temporary registers as being unavailable for reuse.
6945 **
6946 ** Always invoke this procedure after coding a subroutine or co-routine
6947 ** that might be invoked from other parts of the code, to ensure that
6948 ** the sub/co-routine does not use registers in common with the code that
6949 ** invokes the sub/co-routine.
6950 */
6954 }
6956 /*
6957 ** Make sure sufficient registers have been allocated so that
6958 ** iReg is a valid register number.
6959 */
6962 }
6964 #if defined(SQLITE_ENABLE_STAT4) || defined(SQLITE_DEBUG)
6965 /*
6966 ** Return the latest reusable register in the set of all registers.
6967 ** The value returned is no less than iMin. If any register iMin or
6968 ** greater is in permanent use, then return one more than that last
6969 ** permanent register.
6970 */
6978 }
6979 }
6980 }
6984 }
6987 /*
6988 ** Validate that no temporary register falls within the range of
6989 ** iFirst..iLast, inclusive. This routine is only call from within assert()
6990 ** statements.
6991 */
6992 #ifdef SQLITE_DEBUG
6998 ){
7000 }
7004 }
7005 }
7012 }
7013 }
7015 }