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1 /* | |
2 ** 2005 February 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 C code routines that used to generate VDBE code | |
13 ** that implements the ALTER TABLE command. | |
14 */ | |
15 #include "sqliteInt.h" | |
16 | |
17 /* | |
18 ** The code in this file only exists if we are not omitting the | |
19 ** ALTER TABLE logic from the build. | |
20 */ | |
21 #ifndef SQLITE_OMIT_ALTERTABLE | |
22 | |
23 | |
24 /* | |
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: | |
30 ** | |
31 ** sqlite_rename_table('CREATE TABLE abc(a, b, c)', 'def') | |
32 ** -> 'CREATE TABLE def(a, b, c)' | |
33 ** | |
34 ** sqlite_rename_table('CREATE INDEX i ON abc(a)', 'def') | |
35 ** -> 'CREATE INDEX i ON def(a, b, c)' | |
36 */ | |
37 static void renameTableFunc( | |
38 sqlite3_context *context, | |
39 int NotUsed, | |
40 sqlite3_value **argv | |
41 ){ | |
42 unsigned char const *zSql = sqlite3_value_text(argv[0]); | |
43 unsigned char const *zTableName = sqlite3_value_text(argv[1]); | |
44 | |
45 int token; | |
46 Token tname; | |
47 unsigned char const *zCsr = zSql; | |
48 int len = 0; | |
49 char *zRet; | |
50 | |
51 sqlite3 *db = sqlite3_context_db_handle(context); | |
52 | |
53 UNUSED_PARAMETER(NotUsed); | |
54 | |
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. | |
58 */ | |
59 if( zSql ){ | |
60 do { | |
61 if( !*zCsr ){ | |
62 /* Ran out of input before finding an opening bracket. Return NULL. */ | |
63 return; | |
64 } | |
65 | |
66 /* Store the token that zCsr points to in tname. */ | |
67 tname.z = (char*)zCsr; | |
68 tname.n = len; | |
69 | |
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). | |
72 */ | |
73 do { | |
74 zCsr += len; | |
75 len = sqlite3GetToken(zCsr, &token); | |
76 } while( token==TK_SPACE ); | |
77 assert( len>0 ); | |
78 } while( token!=TK_LP && token!=TK_USING ); | |
79 | |
80 zRet = sqlite3MPrintf(db, "%.*s\"%w\"%s", (int)(((u8*)tname.z) - zSql), | |
81 zSql, zTableName, tname.z+tname.n); | |
82 sqlite3_result_text(context, zRet, -1, SQLITE_DYNAMIC); | |
83 } | |
84 } | |
85 | |
86 /* | |
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: | |
91 ** | |
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. | |
95 ** | |
96 ** It returns the new CREATE TABLE statement. For example: | |
97 ** | |
98 ** sqlite_rename_parent('CREATE TABLE t1(a REFERENCES t2)', 't2', 't3') | |
99 ** -> 'CREATE TABLE t1(a REFERENCES t3)' | |
100 */ | |
101 #ifndef SQLITE_OMIT_FOREIGN_KEY | |
102 static void renameParentFunc( | |
103 sqlite3_context *context, | |
104 int NotUsed, | |
105 sqlite3_value **argv | |
106 ){ | |
107 sqlite3 *db = sqlite3_context_db_handle(context); | |
108 char *zOutput = 0; | |
109 char *zResult; | |
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]); | |
113 | |
114 unsigned const char *z; /* Pointer to token */ | |
115 int n; /* Length of token z */ | |
116 int token; /* Type of token */ | |
117 | |
118 UNUSED_PARAMETER(NotUsed); | |
119 if( zInput==0 || zOld==0 ) return; | |
120 for(z=zInput; *z; z=z+n){ | |
121 n = sqlite3GetToken(z, &token); | |
122 if( token==TK_REFERENCES ){ | |
123 char *zParent; | |
124 do { | |
125 z += n; | |
126 n = sqlite3GetToken(z, &token); | |
127 }while( token==TK_SPACE ); | |
128 | |
129 if( token==TK_ILLEGAL ) break; | |
130 zParent = sqlite3DbStrNDup(db, (const char *)z, n); | |
131 if( zParent==0 ) break; | |
132 sqlite3Dequote(zParent); | |
133 if( 0==sqlite3StrICmp((const char *)zOld, zParent) ){ | |
134 char *zOut = sqlite3MPrintf(db, "%s%.*s\"%w\"", | |
135 (zOutput?zOutput:""), (int)(z-zInput), zInput, (const char *)zNew | |
136 ); | |
137 sqlite3DbFree(db, zOutput); | |
138 zOutput = zOut; | |
139 zInput = &z[n]; | |
140 } | |
141 sqlite3DbFree(db, zParent); | |
142 } | |
143 } | |
144 | |
145 zResult = sqlite3MPrintf(db, "%s%s", (zOutput?zOutput:""), zInput), | |
146 sqlite3_result_text(context, zResult, -1, SQLITE_DYNAMIC); | |
147 sqlite3DbFree(db, zOutput); | |
148 } | |
149 #endif | |
150 | |
151 #ifndef SQLITE_OMIT_TRIGGER | |
152 /* This function is used by SQL generated to implement the | |
153 ** ALTER TABLE command. The first argument is the text of a CREATE TRIGGER | |
154 ** statement. The second is a table name. The table name in the CREATE | |
155 ** TRIGGER statement is replaced with the third argument and the result | |
156 ** returned. This is analagous to renameTableFunc() above, except for CREATE | |
157 ** TRIGGER, not CREATE INDEX and CREATE TABLE. | |
158 */ | |
159 static void renameTriggerFunc( | |
160 sqlite3_context *context, | |
161 int NotUsed, | |
162 sqlite3_value **argv | |
163 ){ | |
164 unsigned char const *zSql = sqlite3_value_text(argv[0]); | |
165 unsigned char const *zTableName = sqlite3_value_text(argv[1]); | |
166 | |
167 int token; | |
168 Token tname; | |
169 int dist = 3; | |
170 unsigned char const *zCsr = zSql; | |
171 int len = 0; | |
172 char *zRet; | |
173 sqlite3 *db = sqlite3_context_db_handle(context); | |
174 | |
175 UNUSED_PARAMETER(NotUsed); | |
176 | |
177 /* The principle used to locate the table name in the CREATE TRIGGER | |
178 ** statement is that the table name is the first token that is immediately | |
179 ** preceded by either TK_ON or TK_DOT and immediately followed by one | |
180 ** of TK_WHEN, TK_BEGIN or TK_FOR. | |
181 */ | |
182 if( zSql ){ | |
183 do { | |
184 | |
185 if( !*zCsr ){ | |
186 /* Ran out of input before finding the table name. Return NULL. */ | |
187 return; | |
188 } | |
189 | |
190 /* Store the token that zCsr points to in tname. */ | |
191 tname.z = (char*)zCsr; | |
192 tname.n = len; | |
193 | |
194 /* Advance zCsr to the next token. Store that token type in 'token', | |
195 ** and its length in 'len' (to be used next iteration of this loop). | |
196 */ | |
197 do { | |
198 zCsr += len; | |
199 len = sqlite3GetToken(zCsr, &token); | |
200 }while( token==TK_SPACE ); | |
201 assert( len>0 ); | |
202 | |
203 /* Variable 'dist' stores the number of tokens read since the most | |
204 ** recent TK_DOT or TK_ON. This means that when a WHEN, FOR or BEGIN | |
205 ** token is read and 'dist' equals 2, the condition stated above | |
206 ** to be met. | |
207 ** | |
208 ** Note that ON cannot be a database, table or column name, so | |
209 ** there is no need to worry about syntax like | |
210 ** "CREATE TRIGGER ... ON ON.ON BEGIN ..." etc. | |
211 */ | |
212 dist++; | |
213 if( token==TK_DOT || token==TK_ON ){ | |
214 dist = 0; | |
215 } | |
216 } while( dist!=2 || (token!=TK_WHEN && token!=TK_FOR && token!=TK_BEGIN) ); | |
217 | |
218 /* Variable tname now contains the token that is the old table-name | |
219 ** in the CREATE TRIGGER statement. | |
220 */ | |
221 zRet = sqlite3MPrintf(db, "%.*s\"%w\"%s", (int)(((u8*)tname.z) - zSql), | |
222 zSql, zTableName, tname.z+tname.n); | |
223 sqlite3_result_text(context, zRet, -1, SQLITE_DYNAMIC); | |
224 } | |
225 } | |
226 #endif /* !SQLITE_OMIT_TRIGGER */ | |
227 | |
228 /* | |
229 ** Register built-in functions used to help implement ALTER TABLE | |
230 */ | |
231 void sqlite3AlterFunctions(void){ | |
232 static SQLITE_WSD FuncDef aAlterTableFuncs[] = { | |
233 FUNCTION(sqlite_rename_table, 2, 0, 0, renameTableFunc), | |
234 #ifndef SQLITE_OMIT_TRIGGER | |
235 FUNCTION(sqlite_rename_trigger, 2, 0, 0, renameTriggerFunc), | |
236 #endif | |
237 #ifndef SQLITE_OMIT_FOREIGN_KEY | |
238 FUNCTION(sqlite_rename_parent, 3, 0, 0, renameParentFunc), | |
239 #endif | |
240 }; | |
241 int i; | |
242 FuncDefHash *pHash = &GLOBAL(FuncDefHash, sqlite3GlobalFunctions); | |
243 FuncDef *aFunc = (FuncDef*)&GLOBAL(FuncDef, aAlterTableFuncs); | |
244 | |
245 for(i=0; i<ArraySize(aAlterTableFuncs); i++){ | |
246 sqlite3FuncDefInsert(pHash, &aFunc[i]); | |
247 } | |
248 } | |
249 | |
250 /* | |
251 ** This function is used to create the text of expressions of the form: | |
252 ** | |
253 ** name=<constant1> OR name=<constant2> OR ... | |
254 ** | |
255 ** If argument zWhere is NULL, then a pointer string containing the text | |
256 ** "name=<constant>" is returned, where <constant> is the quoted version | |
257 ** of the string passed as argument zConstant. The returned buffer is | |
258 ** allocated using sqlite3DbMalloc(). It is the responsibility of the | |
259 ** caller to ensure that it is eventually freed. | |
260 ** | |
261 ** If argument zWhere is not NULL, then the string returned is | |
262 ** "<where> OR name=<constant>", where <where> is the contents of zWhere. | |
263 ** In this case zWhere is passed to sqlite3DbFree() before returning. | |
264 ** | |
265 */ | |
266 static char *whereOrName(sqlite3 *db, char *zWhere, char *zConstant){ | |
267 char *zNew; | |
268 if( !zWhere ){ | |
269 zNew = sqlite3MPrintf(db, "name=%Q", zConstant); | |
270 }else{ | |
271 zNew = sqlite3MPrintf(db, "%s OR name=%Q", zWhere, zConstant); | |
272 sqlite3DbFree(db, zWhere); | |
273 } | |
274 return zNew; | |
275 } | |
276 | |
277 #if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER) | |
278 /* | |
279 ** Generate the text of a WHERE expression which can be used to select all | |
280 ** tables that have foreign key constraints that refer to table pTab (i.e. | |
281 ** constraints for which pTab is the parent table) from the sqlite_master | |
282 ** table. | |
283 */ | |
284 static char *whereForeignKeys(Parse *pParse, Table *pTab){ | |
285 FKey *p; | |
286 char *zWhere = 0; | |
287 for(p=sqlite3FkReferences(pTab); p; p=p->pNextTo){ | |
288 zWhere = whereOrName(pParse->db, zWhere, p->pFrom->zName); | |
289 } | |
290 return zWhere; | |
291 } | |
292 #endif | |
293 | |
294 /* | |
295 ** Generate the text of a WHERE expression which can be used to select all | |
296 ** temporary triggers on table pTab from the sqlite_temp_master table. If | |
297 ** table pTab has no temporary triggers, or is itself stored in the | |
298 ** temporary database, NULL is returned. | |
299 */ | |
300 static char *whereTempTriggers(Parse *pParse, Table *pTab){ | |
301 Trigger *pTrig; | |
302 char *zWhere = 0; | |
303 const Schema *pTempSchema = pParse->db->aDb[1].pSchema; /* Temp db schema */ | |
304 | |
305 /* If the table is not located in the temp-db (in which case NULL is | |
306 ** returned, loop through the tables list of triggers. For each trigger | |
307 ** that is not part of the temp-db schema, add a clause to the WHERE | |
308 ** expression being built up in zWhere. | |
309 */ | |
310 if( pTab->pSchema!=pTempSchema ){ | |
311 sqlite3 *db = pParse->db; | |
312 for(pTrig=sqlite3TriggerList(pParse, pTab); pTrig; pTrig=pTrig->pNext){ | |
313 if( pTrig->pSchema==pTempSchema ){ | |
314 zWhere = whereOrName(db, zWhere, pTrig->zName); | |
315 } | |
316 } | |
317 } | |
318 if( zWhere ){ | |
319 char *zNew = sqlite3MPrintf(pParse->db, "type='trigger' AND (%s)", zWhere); | |
320 sqlite3DbFree(pParse->db, zWhere); | |
321 zWhere = zNew; | |
322 } | |
323 return zWhere; | |
324 } | |
325 | |
326 /* | |
327 ** Generate code to drop and reload the internal representation of table | |
328 ** pTab from the database, including triggers and temporary triggers. | |
329 ** Argument zName is the name of the table in the database schema at | |
330 ** the time the generated code is executed. This can be different from | |
331 ** pTab->zName if this function is being called to code part of an | |
332 ** "ALTER TABLE RENAME TO" statement. | |
333 */ | |
334 static void reloadTableSchema(Parse *pParse, Table *pTab, const char *zName){ | |
335 Vdbe *v; | |
336 char *zWhere; | |
337 int iDb; /* Index of database containing pTab */ | |
338 #ifndef SQLITE_OMIT_TRIGGER | |
339 Trigger *pTrig; | |
340 #endif | |
341 | |
342 v = sqlite3GetVdbe(pParse); | |
343 if( NEVER(v==0) ) return; | |
344 assert( sqlite3BtreeHoldsAllMutexes(pParse->db) ); | |
345 iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema); | |
346 assert( iDb>=0 ); | |
347 | |
348 #ifndef SQLITE_OMIT_TRIGGER | |
349 /* Drop any table triggers from the internal schema. */ | |
350 for(pTrig=sqlite3TriggerList(pParse, pTab); pTrig; pTrig=pTrig->pNext){ | |
351 int iTrigDb = sqlite3SchemaToIndex(pParse->db, pTrig->pSchema); | |
352 assert( iTrigDb==iDb || iTrigDb==1 ); | |
353 sqlite3VdbeAddOp4(v, OP_DropTrigger, iTrigDb, 0, 0, pTrig->zName, 0); | |
354 } | |
355 #endif | |
356 | |
357 /* Drop the table and index from the internal schema. */ | |
358 sqlite3VdbeAddOp4(v, OP_DropTable, iDb, 0, 0, pTab->zName, 0); | |
359 | |
360 /* Reload the table, index and permanent trigger schemas. */ | |
361 zWhere = sqlite3MPrintf(pParse->db, "tbl_name=%Q", zName); | |
362 if( !zWhere ) return; | |
363 sqlite3VdbeAddParseSchemaOp(v, iDb, zWhere); | |
364 | |
365 #ifndef SQLITE_OMIT_TRIGGER | |
366 /* Now, if the table is not stored in the temp database, reload any temp | |
367 ** triggers. Don't use IN(...) in case SQLITE_OMIT_SUBQUERY is defined. | |
368 */ | |
369 if( (zWhere=whereTempTriggers(pParse, pTab))!=0 ){ | |
370 sqlite3VdbeAddParseSchemaOp(v, 1, zWhere); | |
371 } | |
372 #endif | |
373 } | |
374 | |
375 /* | |
376 ** Parameter zName is the name of a table that is about to be altered | |
377 ** (either with ALTER TABLE ... RENAME TO or ALTER TABLE ... ADD COLUMN). | |
378 ** If the table is a system table, this function leaves an error message | |
379 ** in pParse->zErr (system tables may not be altered) and returns non-zero. | |
380 ** | |
381 ** Or, if zName is not a system table, zero is returned. | |
382 */ | |
383 static int isSystemTable(Parse *pParse, const char *zName){ | |
384 if( sqlite3Strlen30(zName)>6 && 0==sqlite3StrNICmp(zName, "sqlite_", 7) ){ | |
385 sqlite3ErrorMsg(pParse, "table %s may not be altered", zName); | |
386 return 1; | |
387 } | |
388 return 0; | |
389 } | |
390 | |
391 /* | |
392 ** Generate code to implement the "ALTER TABLE xxx RENAME TO yyy" | |
393 ** command. | |
394 */ | |
395 void sqlite3AlterRenameTable( | |
396 Parse *pParse, /* Parser context. */ | |
397 SrcList *pSrc, /* The table to rename. */ | |
398 Token *pName /* The new table name. */ | |
399 ){ | |
400 int iDb; /* Database that contains the table */ | |
401 char *zDb; /* Name of database iDb */ | |
402 Table *pTab; /* Table being renamed */ | |
403 char *zName = 0; /* NULL-terminated version of pName */ | |
404 sqlite3 *db = pParse->db; /* Database connection */ | |
405 int nTabName; /* Number of UTF-8 characters in zTabName */ | |
406 const char *zTabName; /* Original name of the table */ | |
407 Vdbe *v; | |
408 #ifndef SQLITE_OMIT_TRIGGER | |
409 char *zWhere = 0; /* Where clause to locate temp triggers */ | |
410 #endif | |
411 VTable *pVTab = 0; /* Non-zero if this is a v-tab with an xRename() */ | |
412 int savedDbFlags; /* Saved value of db->flags */ | |
413 | |
414 savedDbFlags = db->flags; | |
415 if( NEVER(db->mallocFailed) ) goto exit_rename_table; | |
416 assert( pSrc->nSrc==1 ); | |
417 assert( sqlite3BtreeHoldsAllMutexes(pParse->db) ); | |
418 | |
419 pTab = sqlite3LocateTableItem(pParse, 0, &pSrc->a[0]); | |
420 if( !pTab ) goto exit_rename_table; | |
421 iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema); | |
422 zDb = db->aDb[iDb].zName; | |
423 db->flags |= SQLITE_PreferBuiltin; | |
424 | |
425 /* Get a NULL terminated version of the new table name. */ | |
426 zName = sqlite3NameFromToken(db, pName); | |
427 if( !zName ) goto exit_rename_table; | |
428 | |
429 /* Check that a table or index named 'zName' does not already exist | |
430 ** in database iDb. If so, this is an error. | |
431 */ | |
432 if( sqlite3FindTable(db, zName, zDb) || sqlite3FindIndex(db, zName, zDb) ){ | |
433 sqlite3ErrorMsg(pParse, | |
434 "there is already another table or index with this name: %s", zName); | |
435 goto exit_rename_table; | |
436 } | |
437 | |
438 /* Make sure it is not a system table being altered, or a reserved name | |
439 ** that the table is being renamed to. | |
440 */ | |
441 if( SQLITE_OK!=isSystemTable(pParse, pTab->zName) ){ | |
442 goto exit_rename_table; | |
443 } | |
444 if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){ goto | |
445 exit_rename_table; | |
446 } | |
447 | |
448 #ifndef SQLITE_OMIT_VIEW | |
449 if( pTab->pSelect ){ | |
450 sqlite3ErrorMsg(pParse, "view %s may not be altered", pTab->zName); | |
451 goto exit_rename_table; | |
452 } | |
453 #endif | |
454 | |
455 #ifndef SQLITE_OMIT_AUTHORIZATION | |
456 /* Invoke the authorization callback. */ | |
457 if( sqlite3AuthCheck(pParse, SQLITE_ALTER_TABLE, zDb, pTab->zName, 0) ){ | |
458 goto exit_rename_table; | |
459 } | |
460 #endif | |
461 | |
462 #ifndef SQLITE_OMIT_VIRTUALTABLE | |
463 if( sqlite3ViewGetColumnNames(pParse, pTab) ){ | |
464 goto exit_rename_table; | |
465 } | |
466 if( IsVirtual(pTab) ){ | |
467 pVTab = sqlite3GetVTable(db, pTab); | |
468 if( pVTab->pVtab->pModule->xRename==0 ){ | |
469 pVTab = 0; | |
470 } | |
471 } | |
472 #endif | |
473 | |
474 /* Begin a transaction for database iDb. | |
475 ** Then modify the schema cookie (since the ALTER TABLE modifies the | |
476 ** schema). Open a statement transaction if the table is a virtual | |
477 ** table. | |
478 */ | |
479 v = sqlite3GetVdbe(pParse); | |
480 if( v==0 ){ | |
481 goto exit_rename_table; | |
482 } | |
483 sqlite3BeginWriteOperation(pParse, pVTab!=0, iDb); | |
484 sqlite3ChangeCookie(pParse, iDb); | |
485 | |
486 /* If this is a virtual table, invoke the xRename() function if | |
487 ** one is defined. The xRename() callback will modify the names | |
488 ** of any resources used by the v-table implementation (including other | |
489 ** SQLite tables) that are identified by the name of the virtual table. | |
490 */ | |
491 #ifndef SQLITE_OMIT_VIRTUALTABLE | |
492 if( pVTab ){ | |
493 int i = ++pParse->nMem; | |
494 sqlite3VdbeLoadString(v, i, zName); | |
495 sqlite3VdbeAddOp4(v, OP_VRename, i, 0, 0,(const char*)pVTab, P4_VTAB); | |
496 sqlite3MayAbort(pParse); | |
497 } | |
498 #endif | |
499 | |
500 /* figure out how many UTF-8 characters are in zName */ | |
501 zTabName = pTab->zName; | |
502 nTabName = sqlite3Utf8CharLen(zTabName, -1); | |
503 | |
504 #if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER) | |
505 if( db->flags&SQLITE_ForeignKeys ){ | |
506 /* If foreign-key support is enabled, rewrite the CREATE TABLE | |
507 ** statements corresponding to all child tables of foreign key constraints | |
508 ** for which the renamed table is the parent table. */ | |
509 if( (zWhere=whereForeignKeys(pParse, pTab))!=0 ){ | |
510 sqlite3NestedParse(pParse, | |
511 "UPDATE \"%w\".%s SET " | |
512 "sql = sqlite_rename_parent(sql, %Q, %Q) " | |
513 "WHERE %s;", zDb, SCHEMA_TABLE(iDb), zTabName, zName, zWhere); | |
514 sqlite3DbFree(db, zWhere); | |
515 } | |
516 } | |
517 #endif | |
518 | |
519 /* Modify the sqlite_master table to use the new table name. */ | |
520 sqlite3NestedParse(pParse, | |
521 "UPDATE %Q.%s SET " | |
522 #ifdef SQLITE_OMIT_TRIGGER | |
523 "sql = sqlite_rename_table(sql, %Q), " | |
524 #else | |
525 "sql = CASE " | |
526 "WHEN type = 'trigger' THEN sqlite_rename_trigger(sql, %Q)" | |
527 "ELSE sqlite_rename_table(sql, %Q) END, " | |
528 #endif | |
529 "tbl_name = %Q, " | |
530 "name = CASE " | |
531 "WHEN type='table' THEN %Q " | |
532 "WHEN name LIKE 'sqlite_autoindex%%' AND type='index' THEN " | |
533 "'sqlite_autoindex_' || %Q || substr(name,%d+18) " | |
534 "ELSE name END " | |
535 "WHERE tbl_name=%Q COLLATE nocase AND " | |
536 "(type='table' OR type='index' OR type='trigger');", | |
537 zDb, SCHEMA_TABLE(iDb), zName, zName, zName, | |
538 #ifndef SQLITE_OMIT_TRIGGER | |
539 zName, | |
540 #endif | |
541 zName, nTabName, zTabName | |
542 ); | |
543 | |
544 #ifndef SQLITE_OMIT_AUTOINCREMENT | |
545 /* If the sqlite_sequence table exists in this database, then update | |
546 ** it with the new table name. | |
547 */ | |
548 if( sqlite3FindTable(db, "sqlite_sequence", zDb) ){ | |
549 sqlite3NestedParse(pParse, | |
550 "UPDATE \"%w\".sqlite_sequence set name = %Q WHERE name = %Q", | |
551 zDb, zName, pTab->zName); | |
552 } | |
553 #endif | |
554 | |
555 #ifndef SQLITE_OMIT_TRIGGER | |
556 /* If there are TEMP triggers on this table, modify the sqlite_temp_master | |
557 ** table. Don't do this if the table being ALTERed is itself located in | |
558 ** the temp database. | |
559 */ | |
560 if( (zWhere=whereTempTriggers(pParse, pTab))!=0 ){ | |
561 sqlite3NestedParse(pParse, | |
562 "UPDATE sqlite_temp_master SET " | |
563 "sql = sqlite_rename_trigger(sql, %Q), " | |
564 "tbl_name = %Q " | |
565 "WHERE %s;", zName, zName, zWhere); | |
566 sqlite3DbFree(db, zWhere); | |
567 } | |
568 #endif | |
569 | |
570 #if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER) | |
571 if( db->flags&SQLITE_ForeignKeys ){ | |
572 FKey *p; | |
573 for(p=sqlite3FkReferences(pTab); p; p=p->pNextTo){ | |
574 Table *pFrom = p->pFrom; | |
575 if( pFrom!=pTab ){ | |
576 reloadTableSchema(pParse, p->pFrom, pFrom->zName); | |
577 } | |
578 } | |
579 } | |
580 #endif | |
581 | |
582 /* Drop and reload the internal table schema. */ | |
583 reloadTableSchema(pParse, pTab, zName); | |
584 | |
585 exit_rename_table: | |
586 sqlite3SrcListDelete(db, pSrc); | |
587 sqlite3DbFree(db, zName); | |
588 db->flags = savedDbFlags; | |
589 } | |
590 | |
591 | |
592 /* | |
593 ** Generate code to make sure the file format number is at least minFormat. | |
594 ** The generated code will increase the file format number if necessary. | |
595 */ | |
596 void sqlite3MinimumFileFormat(Parse *pParse, int iDb, int minFormat){ | |
597 Vdbe *v; | |
598 v = sqlite3GetVdbe(pParse); | |
599 /* The VDBE should have been allocated before this routine is called. | |
600 ** If that allocation failed, we would have quit before reaching this | |
601 ** point */ | |
602 if( ALWAYS(v) ){ | |
603 int r1 = sqlite3GetTempReg(pParse); | |
604 int r2 = sqlite3GetTempReg(pParse); | |
605 int addr1; | |
606 sqlite3VdbeAddOp3(v, OP_ReadCookie, iDb, r1, BTREE_FILE_FORMAT); | |
607 sqlite3VdbeUsesBtree(v, iDb); | |
608 sqlite3VdbeAddOp2(v, OP_Integer, minFormat, r2); | |
609 addr1 = sqlite3VdbeAddOp3(v, OP_Ge, r2, 0, r1); | |
610 sqlite3VdbeChangeP5(v, SQLITE_NOTNULL); VdbeCoverage(v); | |
611 sqlite3VdbeAddOp3(v, OP_SetCookie, iDb, BTREE_FILE_FORMAT, r2); | |
612 sqlite3VdbeJumpHere(v, addr1); | |
613 sqlite3ReleaseTempReg(pParse, r1); | |
614 sqlite3ReleaseTempReg(pParse, r2); | |
615 } | |
616 } | |
617 | |
618 /* | |
619 ** This function is called after an "ALTER TABLE ... ADD" statement | |
620 ** has been parsed. Argument pColDef contains the text of the new | |
621 ** column definition. | |
622 ** | |
623 ** The Table structure pParse->pNewTable was extended to include | |
624 ** the new column during parsing. | |
625 */ | |
626 void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){ | |
627 Table *pNew; /* Copy of pParse->pNewTable */ | |
628 Table *pTab; /* Table being altered */ | |
629 int iDb; /* Database number */ | |
630 const char *zDb; /* Database name */ | |
631 const char *zTab; /* Table name */ | |
632 char *zCol; /* Null-terminated column definition */ | |
633 Column *pCol; /* The new column */ | |
634 Expr *pDflt; /* Default value for the new column */ | |
635 sqlite3 *db; /* The database connection; */ | |
636 | |
637 db = pParse->db; | |
638 if( pParse->nErr || db->mallocFailed ) return; | |
639 pNew = pParse->pNewTable; | |
640 assert( pNew ); | |
641 | |
642 assert( sqlite3BtreeHoldsAllMutexes(db) ); | |
643 iDb = sqlite3SchemaToIndex(db, pNew->pSchema); | |
644 zDb = db->aDb[iDb].zName; | |
645 zTab = &pNew->zName[16]; /* Skip the "sqlite_altertab_" prefix on the name */ | |
646 pCol = &pNew->aCol[pNew->nCol-1]; | |
647 pDflt = pCol->pDflt; | |
648 pTab = sqlite3FindTable(db, zTab, zDb); | |
649 assert( pTab ); | |
650 | |
651 #ifndef SQLITE_OMIT_AUTHORIZATION | |
652 /* Invoke the authorization callback. */ | |
653 if( sqlite3AuthCheck(pParse, SQLITE_ALTER_TABLE, zDb, pTab->zName, 0) ){ | |
654 return; | |
655 } | |
656 #endif | |
657 | |
658 /* If the default value for the new column was specified with a | |
659 ** literal NULL, then set pDflt to 0. This simplifies checking | |
660 ** for an SQL NULL default below. | |
661 */ | |
662 if( pDflt && pDflt->op==TK_NULL ){ | |
663 pDflt = 0; | |
664 } | |
665 | |
666 /* Check that the new column is not specified as PRIMARY KEY or UNIQUE. | |
667 ** If there is a NOT NULL constraint, then the default value for the | |
668 ** column must not be NULL. | |
669 */ | |
670 if( pCol->colFlags & COLFLAG_PRIMKEY ){ | |
671 sqlite3ErrorMsg(pParse, "Cannot add a PRIMARY KEY column"); | |
672 return; | |
673 } | |
674 if( pNew->pIndex ){ | |
675 sqlite3ErrorMsg(pParse, "Cannot add a UNIQUE column"); | |
676 return; | |
677 } | |
678 if( (db->flags&SQLITE_ForeignKeys) && pNew->pFKey && pDflt ){ | |
679 sqlite3ErrorMsg(pParse, | |
680 "Cannot add a REFERENCES column with non-NULL default value"); | |
681 return; | |
682 } | |
683 if( pCol->notNull && !pDflt ){ | |
684 sqlite3ErrorMsg(pParse, | |
685 "Cannot add a NOT NULL column with default value NULL"); | |
686 return; | |
687 } | |
688 | |
689 /* Ensure the default expression is something that sqlite3ValueFromExpr() | |
690 ** can handle (i.e. not CURRENT_TIME etc.) | |
691 */ | |
692 if( pDflt ){ | |
693 sqlite3_value *pVal = 0; | |
694 int rc; | |
695 rc = sqlite3ValueFromExpr(db, pDflt, SQLITE_UTF8, SQLITE_AFF_BLOB, &pVal); | |
696 assert( rc==SQLITE_OK || rc==SQLITE_NOMEM ); | |
697 if( rc!=SQLITE_OK ){ | |
698 db->mallocFailed = 1; | |
699 return; | |
700 } | |
701 if( !pVal ){ | |
702 sqlite3ErrorMsg(pParse, "Cannot add a column with non-constant default"); | |
703 return; | |
704 } | |
705 sqlite3ValueFree(pVal); | |
706 } | |
707 | |
708 /* Modify the CREATE TABLE statement. */ | |
709 zCol = sqlite3DbStrNDup(db, (char*)pColDef->z, pColDef->n); | |
710 if( zCol ){ | |
711 char *zEnd = &zCol[pColDef->n-1]; | |
712 int savedDbFlags = db->flags; | |
713 while( zEnd>zCol && (*zEnd==';' || sqlite3Isspace(*zEnd)) ){ | |
714 *zEnd-- = '\0'; | |
715 } | |
716 db->flags |= SQLITE_PreferBuiltin; | |
717 sqlite3NestedParse(pParse, | |
718 "UPDATE \"%w\".%s SET " | |
719 "sql = substr(sql,1,%d) || ', ' || %Q || substr(sql,%d) " | |
720 "WHERE type = 'table' AND name = %Q", | |
721 zDb, SCHEMA_TABLE(iDb), pNew->addColOffset, zCol, pNew->addColOffset+1, | |
722 zTab | |
723 ); | |
724 sqlite3DbFree(db, zCol); | |
725 db->flags = savedDbFlags; | |
726 } | |
727 | |
728 /* If the default value of the new column is NULL, then set the file | |
729 ** format to 2. If the default value of the new column is not NULL, | |
730 ** the file format becomes 3. | |
731 */ | |
732 sqlite3MinimumFileFormat(pParse, iDb, pDflt ? 3 : 2); | |
733 | |
734 /* Reload the schema of the modified table. */ | |
735 reloadTableSchema(pParse, pTab, pTab->zName); | |
736 } | |
737 | |
738 /* | |
739 ** This function is called by the parser after the table-name in | |
740 ** an "ALTER TABLE <table-name> ADD" statement is parsed. Argument | |
741 ** pSrc is the full-name of the table being altered. | |
742 ** | |
743 ** This routine makes a (partial) copy of the Table structure | |
744 ** for the table being altered and sets Parse.pNewTable to point | |
745 ** to it. Routines called by the parser as the column definition | |
746 ** is parsed (i.e. sqlite3AddColumn()) add the new Column data to | |
747 ** the copy. The copy of the Table structure is deleted by tokenize.c | |
748 ** after parsing is finished. | |
749 ** | |
750 ** Routine sqlite3AlterFinishAddColumn() will be called to complete | |
751 ** coding the "ALTER TABLE ... ADD" statement. | |
752 */ | |
753 void sqlite3AlterBeginAddColumn(Parse *pParse, SrcList *pSrc){ | |
754 Table *pNew; | |
755 Table *pTab; | |
756 Vdbe *v; | |
757 int iDb; | |
758 int i; | |
759 int nAlloc; | |
760 sqlite3 *db = pParse->db; | |
761 | |
762 /* Look up the table being altered. */ | |
763 assert( pParse->pNewTable==0 ); | |
764 assert( sqlite3BtreeHoldsAllMutexes(db) ); | |
765 if( db->mallocFailed ) goto exit_begin_add_column; | |
766 pTab = sqlite3LocateTableItem(pParse, 0, &pSrc->a[0]); | |
767 if( !pTab ) goto exit_begin_add_column; | |
768 | |
769 #ifndef SQLITE_OMIT_VIRTUALTABLE | |
770 if( IsVirtual(pTab) ){ | |
771 sqlite3ErrorMsg(pParse, "virtual tables may not be altered"); | |
772 goto exit_begin_add_column; | |
773 } | |
774 #endif | |
775 | |
776 /* Make sure this is not an attempt to ALTER a view. */ | |
777 if( pTab->pSelect ){ | |
778 sqlite3ErrorMsg(pParse, "Cannot add a column to a view"); | |
779 goto exit_begin_add_column; | |
780 } | |
781 if( SQLITE_OK!=isSystemTable(pParse, pTab->zName) ){ | |
782 goto exit_begin_add_column; | |
783 } | |
784 | |
785 assert( pTab->addColOffset>0 ); | |
786 iDb = sqlite3SchemaToIndex(db, pTab->pSchema); | |
787 | |
788 /* Put a copy of the Table struct in Parse.pNewTable for the | |
789 ** sqlite3AddColumn() function and friends to modify. But modify | |
790 ** the name by adding an "sqlite_altertab_" prefix. By adding this | |
791 ** prefix, we insure that the name will not collide with an existing | |
792 ** table because user table are not allowed to have the "sqlite_" | |
793 ** prefix on their name. | |
794 */ | |
795 pNew = (Table*)sqlite3DbMallocZero(db, sizeof(Table)); | |
796 if( !pNew ) goto exit_begin_add_column; | |
797 pParse->pNewTable = pNew; | |
798 pNew->nRef = 1; | |
799 pNew->nCol = pTab->nCol; | |
800 assert( pNew->nCol>0 ); | |
801 nAlloc = (((pNew->nCol-1)/8)*8)+8; | |
802 assert( nAlloc>=pNew->nCol && nAlloc%8==0 && nAlloc-pNew->nCol<8 ); | |
803 pNew->aCol = (Column*)sqlite3DbMallocZero(db, sizeof(Column)*nAlloc); | |
804 pNew->zName = sqlite3MPrintf(db, "sqlite_altertab_%s", pTab->zName); | |
805 if( !pNew->aCol || !pNew->zName ){ | |
806 db->mallocFailed = 1; | |
807 goto exit_begin_add_column; | |
808 } | |
809 memcpy(pNew->aCol, pTab->aCol, sizeof(Column)*pNew->nCol); | |
810 for(i=0; i<pNew->nCol; i++){ | |
811 Column *pCol = &pNew->aCol[i]; | |
812 pCol->zName = sqlite3DbStrDup(db, pCol->zName); | |
813 pCol->zColl = 0; | |
814 pCol->zType = 0; | |
815 pCol->pDflt = 0; | |
816 pCol->zDflt = 0; | |
817 } | |
818 pNew->pSchema = db->aDb[iDb].pSchema; | |
819 pNew->addColOffset = pTab->addColOffset; | |
820 pNew->nRef = 1; | |
821 | |
822 /* Begin a transaction and increment the schema cookie. */ | |
823 sqlite3BeginWriteOperation(pParse, 0, iDb); | |
824 v = sqlite3GetVdbe(pParse); | |
825 if( !v ) goto exit_begin_add_column; | |
826 sqlite3ChangeCookie(pParse, iDb); | |
827 | |
828 exit_begin_add_column: | |
829 sqlite3SrcListDelete(db, pSrc); | |
830 return; | |
831 } | |
832 #endif /* SQLITE_ALTER_TABLE */ | |
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