4 ** The author disclaims copyright to this source code. In place of
5 ** a legal notice, here is a blessing:
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.
11 *************************************************************************
12 ** This file contains C code routines that used to generate VDBE code
13 ** that implements the ALTER TABLE command.
15 #include "sqliteInt.h"
18 ** The code in this file only exists if we are not omitting the
19 ** ALTER TABLE logic from the build.
21 #ifndef SQLITE_OMIT_ALTERTABLE
25 ** This function is used by SQL generated to implement the
26 ** ALTER TABLE command. The first argument is the text of a CREATE TABLE or
27 ** CREATE INDEX command. The second is a table name. The table name in
28 ** the CREATE TABLE or CREATE INDEX statement is replaced with the third
29 ** argument and the result returned. Examples:
31 ** sqlite_rename_table('CREATE TABLE abc(a, b, c)', 'def')
32 ** -> 'CREATE TABLE def(a, b, c)'
34 ** sqlite_rename_table('CREATE INDEX i ON abc(a)', 'def')
35 ** -> 'CREATE INDEX i ON def(a, b, c)'
37 static void renameTableFunc(
38 sqlite3_context
*context
,
42 unsigned char const *zSql
= sqlite3_value_text(argv
[0]);
43 unsigned char const *zTableName
= sqlite3_value_text(argv
[1]);
47 unsigned char const *zCsr
= zSql
;
51 sqlite3
*db
= sqlite3_context_db_handle(context
);
53 UNUSED_PARAMETER(NotUsed
);
55 /* The principle used to locate the table name in the CREATE TABLE
56 ** statement is that the table name is the first non-space token that
57 ** is immediately followed by a TK_LP or TK_USING token.
62 /* Ran out of input before finding an opening bracket. Return NULL. */
66 /* Store the token that zCsr points to in tname. */
67 tname
.z
= (char*)zCsr
;
70 /* Advance zCsr to the next token. Store that token type in 'token',
71 ** and its length in 'len' (to be used next iteration of this loop).
75 len
= sqlite3GetToken(zCsr
, &token
);
76 } while( token
==TK_SPACE
);
78 } while( token
!=TK_LP
&& token
!=TK_USING
);
80 zRet
= sqlite3MPrintf(db
, "%.*s\"%w\"%s", ((u8
*)tname
.z
) - zSql
, zSql
,
81 zTableName
, tname
.z
+tname
.n
);
82 sqlite3_result_text(context
, zRet
, -1, SQLITE_DYNAMIC
);
87 ** This C function implements an SQL user function that is used by SQL code
88 ** generated by the ALTER TABLE ... RENAME command to modify the definition
89 ** of any foreign key constraints that use the table being renamed as the
90 ** parent table. It is passed three arguments:
92 ** 1) The complete text of the CREATE TABLE statement being modified,
93 ** 2) The old name of the table being renamed, and
94 ** 3) The new name of the table being renamed.
96 ** It returns the new CREATE TABLE statement. For example:
98 ** sqlite_rename_parent('CREATE TABLE t1(a REFERENCES t2)', 't2', 't3')
99 ** -> 'CREATE TABLE t1(a REFERENCES t3)'
101 #ifndef SQLITE_OMIT_FOREIGN_KEY
102 static void renameParentFunc(
103 sqlite3_context
*context
,
107 sqlite3
*db
= sqlite3_context_db_handle(context
);
110 unsigned char const *zInput
= sqlite3_value_text(argv
[0]);
111 unsigned char const *zOld
= sqlite3_value_text(argv
[1]);
112 unsigned char const *zNew
= sqlite3_value_text(argv
[2]);
114 unsigned const char *z
; /* Pointer to token */
115 int n
; /* Length of token z */
116 int token
; /* Type of token */
118 UNUSED_PARAMETER(NotUsed
);
119 for(z
=zInput
; *z
; z
=z
+n
){
120 n
= sqlite3GetToken(z
, &token
);
121 if( token
==TK_REFERENCES
){
125 n
= sqlite3GetToken(z
, &token
);
126 }while( token
==TK_SPACE
);
128 zParent
= sqlite3DbStrNDup(db
, (const char *)z
, n
);
129 if( zParent
==0 ) break;
130 sqlite3Dequote(zParent
);
131 if( 0==sqlite3StrICmp((const char *)zOld
, zParent
) ){
132 char *zOut
= sqlite3MPrintf(db
, "%s%.*s\"%w\"",
133 (zOutput
?zOutput
:""), z
-zInput
, zInput
, (const char *)zNew
135 sqlite3DbFree(db
, zOutput
);
139 sqlite3DbFree(db
, zParent
);
143 zResult
= sqlite3MPrintf(db
, "%s%s", (zOutput
?zOutput
:""), zInput
),
144 sqlite3_result_text(context
, zResult
, -1, SQLITE_DYNAMIC
);
145 sqlite3DbFree(db
, zOutput
);
149 #ifndef SQLITE_OMIT_TRIGGER
150 /* This function is used by SQL generated to implement the
151 ** ALTER TABLE command. The first argument is the text of a CREATE TRIGGER
152 ** statement. The second is a table name. The table name in the CREATE
153 ** TRIGGER statement is replaced with the third argument and the result
154 ** returned. This is analagous to renameTableFunc() above, except for CREATE
155 ** TRIGGER, not CREATE INDEX and CREATE TABLE.
157 static void renameTriggerFunc(
158 sqlite3_context
*context
,
162 unsigned char const *zSql
= sqlite3_value_text(argv
[0]);
163 unsigned char const *zTableName
= sqlite3_value_text(argv
[1]);
168 unsigned char const *zCsr
= zSql
;
171 sqlite3
*db
= sqlite3_context_db_handle(context
);
173 UNUSED_PARAMETER(NotUsed
);
175 /* The principle used to locate the table name in the CREATE TRIGGER
176 ** statement is that the table name is the first token that is immediatedly
177 ** preceded by either TK_ON or TK_DOT and immediatedly followed by one
178 ** of TK_WHEN, TK_BEGIN or TK_FOR.
184 /* Ran out of input before finding the table name. Return NULL. */
188 /* Store the token that zCsr points to in tname. */
189 tname
.z
= (char*)zCsr
;
192 /* Advance zCsr to the next token. Store that token type in 'token',
193 ** and its length in 'len' (to be used next iteration of this loop).
197 len
= sqlite3GetToken(zCsr
, &token
);
198 }while( token
==TK_SPACE
);
201 /* Variable 'dist' stores the number of tokens read since the most
202 ** recent TK_DOT or TK_ON. This means that when a WHEN, FOR or BEGIN
203 ** token is read and 'dist' equals 2, the condition stated above
206 ** Note that ON cannot be a database, table or column name, so
207 ** there is no need to worry about syntax like
208 ** "CREATE TRIGGER ... ON ON.ON BEGIN ..." etc.
211 if( token
==TK_DOT
|| token
==TK_ON
){
214 } while( dist
!=2 || (token
!=TK_WHEN
&& token
!=TK_FOR
&& token
!=TK_BEGIN
) );
216 /* Variable tname now contains the token that is the old table-name
217 ** in the CREATE TRIGGER statement.
219 zRet
= sqlite3MPrintf(db
, "%.*s\"%w\"%s", ((u8
*)tname
.z
) - zSql
, zSql
,
220 zTableName
, tname
.z
+tname
.n
);
221 sqlite3_result_text(context
, zRet
, -1, SQLITE_DYNAMIC
);
224 #endif /* !SQLITE_OMIT_TRIGGER */
227 ** Register built-in functions used to help implement ALTER TABLE
229 void sqlite3AlterFunctions(void){
230 static SQLITE_WSD FuncDef aAlterTableFuncs
[] = {
231 FUNCTION(sqlite_rename_table
, 2, 0, 0, renameTableFunc
),
232 #ifndef SQLITE_OMIT_TRIGGER
233 FUNCTION(sqlite_rename_trigger
, 2, 0, 0, renameTriggerFunc
),
235 #ifndef SQLITE_OMIT_FOREIGN_KEY
236 FUNCTION(sqlite_rename_parent
, 3, 0, 0, renameParentFunc
),
240 FuncDefHash
*pHash
= &GLOBAL(FuncDefHash
, sqlite3GlobalFunctions
);
241 FuncDef
*aFunc
= (FuncDef
*)&GLOBAL(FuncDef
, aAlterTableFuncs
);
243 for(i
=0; i
<ArraySize(aAlterTableFuncs
); i
++){
244 sqlite3FuncDefInsert(pHash
, &aFunc
[i
]);
249 ** This function is used to create the text of expressions of the form:
251 ** name=<constant1> OR name=<constant2> OR ...
253 ** If argument zWhere is NULL, then a pointer string containing the text
254 ** "name=<constant>" is returned, where <constant> is the quoted version
255 ** of the string passed as argument zConstant. The returned buffer is
256 ** allocated using sqlite3DbMalloc(). It is the responsibility of the
257 ** caller to ensure that it is eventually freed.
259 ** If argument zWhere is not NULL, then the string returned is
260 ** "<where> OR name=<constant>", where <where> is the contents of zWhere.
261 ** In this case zWhere is passed to sqlite3DbFree() before returning.
264 static char *whereOrName(sqlite3
*db
, char *zWhere
, char *zConstant
){
267 zNew
= sqlite3MPrintf(db
, "name=%Q", zConstant
);
269 zNew
= sqlite3MPrintf(db
, "%s OR name=%Q", zWhere
, zConstant
);
270 sqlite3DbFree(db
, zWhere
);
275 #if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
277 ** Generate the text of a WHERE expression which can be used to select all
278 ** tables that have foreign key constraints that refer to table pTab (i.e.
279 ** constraints for which pTab is the parent table) from the sqlite_master
282 static char *whereForeignKeys(Parse
*pParse
, Table
*pTab
){
285 for(p
=sqlite3FkReferences(pTab
); p
; p
=p
->pNextTo
){
286 zWhere
= whereOrName(pParse
->db
, zWhere
, p
->pFrom
->zName
);
293 ** Generate the text of a WHERE expression which can be used to select all
294 ** temporary triggers on table pTab from the sqlite_temp_master table. If
295 ** table pTab has no temporary triggers, or is itself stored in the
296 ** temporary database, NULL is returned.
298 static char *whereTempTriggers(Parse
*pParse
, Table
*pTab
){
301 const Schema
*pTempSchema
= pParse
->db
->aDb
[1].pSchema
; /* Temp db schema */
303 /* If the table is not located in the temp-db (in which case NULL is
304 ** returned, loop through the tables list of triggers. For each trigger
305 ** that is not part of the temp-db schema, add a clause to the WHERE
306 ** expression being built up in zWhere.
308 if( pTab
->pSchema
!=pTempSchema
){
309 sqlite3
*db
= pParse
->db
;
310 for(pTrig
=sqlite3TriggerList(pParse
, pTab
); pTrig
; pTrig
=pTrig
->pNext
){
311 if( pTrig
->pSchema
==pTempSchema
){
312 zWhere
= whereOrName(db
, zWhere
, pTrig
->zName
);
317 char *zNew
= sqlite3MPrintf(pParse
->db
, "type='trigger' AND (%s)", zWhere
);
318 sqlite3DbFree(pParse
->db
, zWhere
);
325 ** Generate code to drop and reload the internal representation of table
326 ** pTab from the database, including triggers and temporary triggers.
327 ** Argument zName is the name of the table in the database schema at
328 ** the time the generated code is executed. This can be different from
329 ** pTab->zName if this function is being called to code part of an
330 ** "ALTER TABLE RENAME TO" statement.
332 static void reloadTableSchema(Parse
*pParse
, Table
*pTab
, const char *zName
){
335 int iDb
; /* Index of database containing pTab */
336 #ifndef SQLITE_OMIT_TRIGGER
340 v
= sqlite3GetVdbe(pParse
);
341 if( NEVER(v
==0) ) return;
342 assert( sqlite3BtreeHoldsAllMutexes(pParse
->db
) );
343 iDb
= sqlite3SchemaToIndex(pParse
->db
, pTab
->pSchema
);
346 #ifndef SQLITE_OMIT_TRIGGER
347 /* Drop any table triggers from the internal schema. */
348 for(pTrig
=sqlite3TriggerList(pParse
, pTab
); pTrig
; pTrig
=pTrig
->pNext
){
349 int iTrigDb
= sqlite3SchemaToIndex(pParse
->db
, pTrig
->pSchema
);
350 assert( iTrigDb
==iDb
|| iTrigDb
==1 );
351 sqlite3VdbeAddOp4(v
, OP_DropTrigger
, iTrigDb
, 0, 0, pTrig
->zName
, 0);
355 /* Drop the table and index from the internal schema. */
356 sqlite3VdbeAddOp4(v
, OP_DropTable
, iDb
, 0, 0, pTab
->zName
, 0);
358 /* Reload the table, index and permanent trigger schemas. */
359 zWhere
= sqlite3MPrintf(pParse
->db
, "tbl_name=%Q", zName
);
360 if( !zWhere
) return;
361 sqlite3VdbeAddOp4(v
, OP_ParseSchema
, iDb
, 0, 0, zWhere
, P4_DYNAMIC
);
363 #ifndef SQLITE_OMIT_TRIGGER
364 /* Now, if the table is not stored in the temp database, reload any temp
365 ** triggers. Don't use IN(...) in case SQLITE_OMIT_SUBQUERY is defined.
367 if( (zWhere
=whereTempTriggers(pParse
, pTab
))!=0 ){
368 sqlite3VdbeAddOp4(v
, OP_ParseSchema
, 1, 0, 0, zWhere
, P4_DYNAMIC
);
374 ** Parameter zName is the name of a table that is about to be altered
375 ** (either with ALTER TABLE ... RENAME TO or ALTER TABLE ... ADD COLUMN).
376 ** If the table is a system table, this function leaves an error message
377 ** in pParse->zErr (system tables may not be altered) and returns non-zero.
379 ** Or, if zName is not a system table, zero is returned.
381 static int isSystemTable(Parse
*pParse
, const char *zName
){
382 if( sqlite3Strlen30(zName
)>6 && 0==sqlite3StrNICmp(zName
, "sqlite_", 7) ){
383 sqlite3ErrorMsg(pParse
, "table %s may not be altered", zName
);
390 ** Generate code to implement the "ALTER TABLE xxx RENAME TO yyy"
393 void sqlite3AlterRenameTable(
394 Parse
*pParse
, /* Parser context. */
395 SrcList
*pSrc
, /* The table to rename. */
396 Token
*pName
/* The new table name. */
398 int iDb
; /* Database that contains the table */
399 char *zDb
; /* Name of database iDb */
400 Table
*pTab
; /* Table being renamed */
401 char *zName
= 0; /* NULL-terminated version of pName */
402 sqlite3
*db
= pParse
->db
; /* Database connection */
403 int nTabName
; /* Number of UTF-8 characters in zTabName */
404 const char *zTabName
; /* Original name of the table */
406 #ifndef SQLITE_OMIT_TRIGGER
407 char *zWhere
= 0; /* Where clause to locate temp triggers */
409 VTable
*pVTab
= 0; /* Non-zero if this is a v-tab with an xRename() */
410 int savedDbFlags
; /* Saved value of db->flags */
412 savedDbFlags
= db
->flags
;
413 if( NEVER(db
->mallocFailed
) ) goto exit_rename_table
;
414 assert( pSrc
->nSrc
==1 );
415 assert( sqlite3BtreeHoldsAllMutexes(pParse
->db
) );
417 pTab
= sqlite3LocateTable(pParse
, 0, pSrc
->a
[0].zName
, pSrc
->a
[0].zDatabase
);
418 if( !pTab
) goto exit_rename_table
;
419 iDb
= sqlite3SchemaToIndex(pParse
->db
, pTab
->pSchema
);
420 zDb
= db
->aDb
[iDb
].zName
;
421 db
->flags
|= SQLITE_PreferBuiltin
;
423 /* Get a NULL terminated version of the new table name. */
424 zName
= sqlite3NameFromToken(db
, pName
);
425 if( !zName
) goto exit_rename_table
;
427 /* Check that a table or index named 'zName' does not already exist
428 ** in database iDb. If so, this is an error.
430 if( sqlite3FindTable(db
, zName
, zDb
) || sqlite3FindIndex(db
, zName
, zDb
) ){
431 sqlite3ErrorMsg(pParse
,
432 "there is already another table or index with this name: %s", zName
);
433 goto exit_rename_table
;
436 /* Make sure it is not a system table being altered, or a reserved name
437 ** that the table is being renamed to.
439 if( SQLITE_OK
!=isSystemTable(pParse
, pTab
->zName
) ){
440 goto exit_rename_table
;
442 if( SQLITE_OK
!=sqlite3CheckObjectName(pParse
, zName
) ){ goto
446 #ifndef SQLITE_OMIT_VIEW
448 sqlite3ErrorMsg(pParse
, "view %s may not be altered", pTab
->zName
);
449 goto exit_rename_table
;
453 #ifndef SQLITE_OMIT_AUTHORIZATION
454 /* Invoke the authorization callback. */
455 if( sqlite3AuthCheck(pParse
, SQLITE_ALTER_TABLE
, zDb
, pTab
->zName
, 0) ){
456 goto exit_rename_table
;
460 #ifndef SQLITE_OMIT_VIRTUALTABLE
461 if( sqlite3ViewGetColumnNames(pParse
, pTab
) ){
462 goto exit_rename_table
;
464 if( IsVirtual(pTab
) ){
465 pVTab
= sqlite3GetVTable(db
, pTab
);
466 if( pVTab
->pVtab
->pModule
->xRename
==0 ){
472 /* Begin a transaction and code the VerifyCookie for database iDb.
473 ** Then modify the schema cookie (since the ALTER TABLE modifies the
474 ** schema). Open a statement transaction if the table is a virtual
477 v
= sqlite3GetVdbe(pParse
);
479 goto exit_rename_table
;
481 sqlite3BeginWriteOperation(pParse
, pVTab
!=0, iDb
);
482 sqlite3ChangeCookie(pParse
, iDb
);
484 /* If this is a virtual table, invoke the xRename() function if
485 ** one is defined. The xRename() callback will modify the names
486 ** of any resources used by the v-table implementation (including other
487 ** SQLite tables) that are identified by the name of the virtual table.
489 #ifndef SQLITE_OMIT_VIRTUALTABLE
491 int i
= ++pParse
->nMem
;
492 sqlite3VdbeAddOp4(v
, OP_String8
, 0, i
, 0, zName
, 0);
493 sqlite3VdbeAddOp4(v
, OP_VRename
, i
, 0, 0,(const char*)pVTab
, P4_VTAB
);
494 sqlite3MayAbort(pParse
);
498 /* figure out how many UTF-8 characters are in zName */
499 zTabName
= pTab
->zName
;
500 nTabName
= sqlite3Utf8CharLen(zTabName
, -1);
502 #if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
503 if( db
->flags
&SQLITE_ForeignKeys
){
504 /* If foreign-key support is enabled, rewrite the CREATE TABLE
505 ** statements corresponding to all child tables of foreign key constraints
506 ** for which the renamed table is the parent table. */
507 if( (zWhere
=whereForeignKeys(pParse
, pTab
))!=0 ){
508 sqlite3NestedParse(pParse
,
509 "UPDATE \"%w\".%s SET "
510 "sql = sqlite_rename_parent(sql, %Q, %Q) "
511 "WHERE %s;", zDb
, SCHEMA_TABLE(iDb
), zTabName
, zName
, zWhere
);
512 sqlite3DbFree(db
, zWhere
);
517 /* Modify the sqlite_master table to use the new table name. */
518 sqlite3NestedParse(pParse
,
520 #ifdef SQLITE_OMIT_TRIGGER
521 "sql = sqlite_rename_table(sql, %Q), "
524 "WHEN type = 'trigger' THEN sqlite_rename_trigger(sql, %Q)"
525 "ELSE sqlite_rename_table(sql, %Q) END, "
529 "WHEN type='table' THEN %Q "
530 "WHEN name LIKE 'sqlite_autoindex%%' AND type='index' THEN "
531 "'sqlite_autoindex_' || %Q || substr(name,%d+18) "
533 "WHERE tbl_name=%Q AND "
534 "(type='table' OR type='index' OR type='trigger');",
535 zDb
, SCHEMA_TABLE(iDb
), zName
, zName
, zName
,
536 #ifndef SQLITE_OMIT_TRIGGER
539 zName
, nTabName
, zTabName
542 #ifndef SQLITE_OMIT_AUTOINCREMENT
543 /* If the sqlite_sequence table exists in this database, then update
544 ** it with the new table name.
546 if( sqlite3FindTable(db
, "sqlite_sequence", zDb
) ){
547 sqlite3NestedParse(pParse
,
548 "UPDATE \"%w\".sqlite_sequence set name = %Q WHERE name = %Q",
549 zDb
, zName
, pTab
->zName
);
553 #ifndef SQLITE_OMIT_TRIGGER
554 /* If there are TEMP triggers on this table, modify the sqlite_temp_master
555 ** table. Don't do this if the table being ALTERed is itself located in
556 ** the temp database.
558 if( (zWhere
=whereTempTriggers(pParse
, pTab
))!=0 ){
559 sqlite3NestedParse(pParse
,
560 "UPDATE sqlite_temp_master SET "
561 "sql = sqlite_rename_trigger(sql, %Q), "
563 "WHERE %s;", zName
, zName
, zWhere
);
564 sqlite3DbFree(db
, zWhere
);
568 #if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
569 if( db
->flags
&SQLITE_ForeignKeys
){
571 for(p
=sqlite3FkReferences(pTab
); p
; p
=p
->pNextTo
){
572 Table
*pFrom
= p
->pFrom
;
574 reloadTableSchema(pParse
, p
->pFrom
, pFrom
->zName
);
580 /* Drop and reload the internal table schema. */
581 reloadTableSchema(pParse
, pTab
, zName
);
584 sqlite3SrcListDelete(db
, pSrc
);
585 sqlite3DbFree(db
, zName
);
586 db
->flags
= savedDbFlags
;
591 ** Generate code to make sure the file format number is at least minFormat.
592 ** The generated code will increase the file format number if necessary.
594 void sqlite3MinimumFileFormat(Parse
*pParse
, int iDb
, int minFormat
){
596 v
= sqlite3GetVdbe(pParse
);
597 /* The VDBE should have been allocated before this routine is called.
598 ** If that allocation failed, we would have quit before reaching this
601 int r1
= sqlite3GetTempReg(pParse
);
602 int r2
= sqlite3GetTempReg(pParse
);
604 sqlite3VdbeAddOp3(v
, OP_ReadCookie
, iDb
, r1
, BTREE_FILE_FORMAT
);
605 sqlite3VdbeUsesBtree(v
, iDb
);
606 sqlite3VdbeAddOp2(v
, OP_Integer
, minFormat
, r2
);
607 j1
= sqlite3VdbeAddOp3(v
, OP_Ge
, r2
, 0, r1
);
608 sqlite3VdbeAddOp3(v
, OP_SetCookie
, iDb
, BTREE_FILE_FORMAT
, r2
);
609 sqlite3VdbeJumpHere(v
, j1
);
610 sqlite3ReleaseTempReg(pParse
, r1
);
611 sqlite3ReleaseTempReg(pParse
, r2
);
616 ** This function is called after an "ALTER TABLE ... ADD" statement
617 ** has been parsed. Argument pColDef contains the text of the new
618 ** column definition.
620 ** The Table structure pParse->pNewTable was extended to include
621 ** the new column during parsing.
623 void sqlite3AlterFinishAddColumn(Parse
*pParse
, Token
*pColDef
){
624 Table
*pNew
; /* Copy of pParse->pNewTable */
625 Table
*pTab
; /* Table being altered */
626 int iDb
; /* Database number */
627 const char *zDb
; /* Database name */
628 const char *zTab
; /* Table name */
629 char *zCol
; /* Null-terminated column definition */
630 Column
*pCol
; /* The new column */
631 Expr
*pDflt
; /* Default value for the new column */
632 sqlite3
*db
; /* The database connection; */
635 if( pParse
->nErr
|| db
->mallocFailed
) return;
636 pNew
= pParse
->pNewTable
;
639 assert( sqlite3BtreeHoldsAllMutexes(db
) );
640 iDb
= sqlite3SchemaToIndex(db
, pNew
->pSchema
);
641 zDb
= db
->aDb
[iDb
].zName
;
642 zTab
= &pNew
->zName
[16]; /* Skip the "sqlite_altertab_" prefix on the name */
643 pCol
= &pNew
->aCol
[pNew
->nCol
-1];
645 pTab
= sqlite3FindTable(db
, zTab
, zDb
);
648 #ifndef SQLITE_OMIT_AUTHORIZATION
649 /* Invoke the authorization callback. */
650 if( sqlite3AuthCheck(pParse
, SQLITE_ALTER_TABLE
, zDb
, pTab
->zName
, 0) ){
655 /* If the default value for the new column was specified with a
656 ** literal NULL, then set pDflt to 0. This simplifies checking
657 ** for an SQL NULL default below.
659 if( pDflt
&& pDflt
->op
==TK_NULL
){
663 /* Check that the new column is not specified as PRIMARY KEY or UNIQUE.
664 ** If there is a NOT NULL constraint, then the default value for the
665 ** column must not be NULL.
667 if( pCol
->isPrimKey
){
668 sqlite3ErrorMsg(pParse
, "Cannot add a PRIMARY KEY column");
672 sqlite3ErrorMsg(pParse
, "Cannot add a UNIQUE column");
675 if( (db
->flags
&SQLITE_ForeignKeys
) && pNew
->pFKey
&& pDflt
){
676 sqlite3ErrorMsg(pParse
,
677 "Cannot add a REFERENCES column with non-NULL default value");
680 if( pCol
->notNull
&& !pDflt
){
681 sqlite3ErrorMsg(pParse
,
682 "Cannot add a NOT NULL column with default value NULL");
686 /* Ensure the default expression is something that sqlite3ValueFromExpr()
687 ** can handle (i.e. not CURRENT_TIME etc.)
691 if( sqlite3ValueFromExpr(db
, pDflt
, SQLITE_UTF8
, SQLITE_AFF_NONE
, &pVal
) ){
692 db
->mallocFailed
= 1;
696 sqlite3ErrorMsg(pParse
, "Cannot add a column with non-constant default");
699 sqlite3ValueFree(pVal
);
702 /* Modify the CREATE TABLE statement. */
703 zCol
= sqlite3DbStrNDup(db
, (char*)pColDef
->z
, pColDef
->n
);
705 char *zEnd
= &zCol
[pColDef
->n
-1];
706 int savedDbFlags
= db
->flags
;
707 while( zEnd
>zCol
&& (*zEnd
==';' || sqlite3Isspace(*zEnd
)) ){
710 db
->flags
|= SQLITE_PreferBuiltin
;
711 sqlite3NestedParse(pParse
,
712 "UPDATE \"%w\".%s SET "
713 "sql = substr(sql,1,%d) || ', ' || %Q || substr(sql,%d) "
714 "WHERE type = 'table' AND name = %Q",
715 zDb
, SCHEMA_TABLE(iDb
), pNew
->addColOffset
, zCol
, pNew
->addColOffset
+1,
718 sqlite3DbFree(db
, zCol
);
719 db
->flags
= savedDbFlags
;
722 /* If the default value of the new column is NULL, then set the file
723 ** format to 2. If the default value of the new column is not NULL,
724 ** the file format becomes 3.
726 sqlite3MinimumFileFormat(pParse
, iDb
, pDflt
? 3 : 2);
728 /* Reload the schema of the modified table. */
729 reloadTableSchema(pParse
, pTab
, pTab
->zName
);
733 ** This function is called by the parser after the table-name in
734 ** an "ALTER TABLE <table-name> ADD" statement is parsed. Argument
735 ** pSrc is the full-name of the table being altered.
737 ** This routine makes a (partial) copy of the Table structure
738 ** for the table being altered and sets Parse.pNewTable to point
739 ** to it. Routines called by the parser as the column definition
740 ** is parsed (i.e. sqlite3AddColumn()) add the new Column data to
741 ** the copy. The copy of the Table structure is deleted by tokenize.c
742 ** after parsing is finished.
744 ** Routine sqlite3AlterFinishAddColumn() will be called to complete
745 ** coding the "ALTER TABLE ... ADD" statement.
747 void sqlite3AlterBeginAddColumn(Parse
*pParse
, SrcList
*pSrc
){
754 sqlite3
*db
= pParse
->db
;
756 /* Look up the table being altered. */
757 assert( pParse
->pNewTable
==0 );
758 assert( sqlite3BtreeHoldsAllMutexes(db
) );
759 if( db
->mallocFailed
) goto exit_begin_add_column
;
760 pTab
= sqlite3LocateTable(pParse
, 0, pSrc
->a
[0].zName
, pSrc
->a
[0].zDatabase
);
761 if( !pTab
) goto exit_begin_add_column
;
763 #ifndef SQLITE_OMIT_VIRTUALTABLE
764 if( IsVirtual(pTab
) ){
765 sqlite3ErrorMsg(pParse
, "virtual tables may not be altered");
766 goto exit_begin_add_column
;
770 /* Make sure this is not an attempt to ALTER a view. */
772 sqlite3ErrorMsg(pParse
, "Cannot add a column to a view");
773 goto exit_begin_add_column
;
775 if( SQLITE_OK
!=isSystemTable(pParse
, pTab
->zName
) ){
776 goto exit_begin_add_column
;
779 assert( pTab
->addColOffset
>0 );
780 iDb
= sqlite3SchemaToIndex(db
, pTab
->pSchema
);
782 /* Put a copy of the Table struct in Parse.pNewTable for the
783 ** sqlite3AddColumn() function and friends to modify. But modify
784 ** the name by adding an "sqlite_altertab_" prefix. By adding this
785 ** prefix, we insure that the name will not collide with an existing
786 ** table because user table are not allowed to have the "sqlite_"
787 ** prefix on their name.
789 pNew
= (Table
*)sqlite3DbMallocZero(db
, sizeof(Table
));
790 if( !pNew
) goto exit_begin_add_column
;
791 pParse
->pNewTable
= pNew
;
793 pNew
->nCol
= pTab
->nCol
;
794 assert( pNew
->nCol
>0 );
795 nAlloc
= (((pNew
->nCol
-1)/8)*8)+8;
796 assert( nAlloc
>=pNew
->nCol
&& nAlloc
%8==0 && nAlloc
-pNew
->nCol
<8 );
797 pNew
->aCol
= (Column
*)sqlite3DbMallocZero(db
, sizeof(Column
)*nAlloc
);
798 pNew
->zName
= sqlite3MPrintf(db
, "sqlite_altertab_%s", pTab
->zName
);
799 if( !pNew
->aCol
|| !pNew
->zName
){
800 db
->mallocFailed
= 1;
801 goto exit_begin_add_column
;
803 memcpy(pNew
->aCol
, pTab
->aCol
, sizeof(Column
)*pNew
->nCol
);
804 for(i
=0; i
<pNew
->nCol
; i
++){
805 Column
*pCol
= &pNew
->aCol
[i
];
806 pCol
->zName
= sqlite3DbStrDup(db
, pCol
->zName
);
812 pNew
->pSchema
= db
->aDb
[iDb
].pSchema
;
813 pNew
->addColOffset
= pTab
->addColOffset
;
816 /* Begin a transaction and increment the schema cookie. */
817 sqlite3BeginWriteOperation(pParse
, 0, iDb
);
818 v
= sqlite3GetVdbe(pParse
);
819 if( !v
) goto exit_begin_add_column
;
820 sqlite3ChangeCookie(pParse
, iDb
);
822 exit_begin_add_column
:
823 sqlite3SrcListDelete(db
, pSrc
);
826 #endif /* SQLITE_ALTER_TABLE */