When ALTER TABLE RENAME TO is used to change the name of a table that is the parent table of a foreign key constraint, modify that foreign key constraint to use the new table name.

FossilOrigin-Name: b4a10c39e726dc190e9597e382baddc034294114
2025-11-06 15:49:35 +03:00 · 2009-09-26 17:51:48 +00:00
parent 0ff297eaa7
commit 432cc5b9f3
6 changed files with 207 additions and 24 deletions
--- a/18
+++ b/18
@@ -1,5 +1,5 @@
-C Avoid\schecking\sif\san\sinsert\sor\sdelete\shas\s"fixed"\san\soutstanding\sFK\sconstraint\sviolation\sif\sthe\sconstraint\scounter\sindicates\sthat\sthe\sdatabase\scontains\sno\ssuch\sviolations.
-D 2009-09-25T17:03:14
+C When\sALTER\sTABLE\sRENAME\sTO\sis\sused\sto\schange\sthe\sname\sof\sa\stable\sthat\sis\sthe\sparent\stable\sof\sa\sforeign\skey\sconstraint,\smodify\sthat\sforeign\skey\sconstraint\sto\suse\sthe\snew\stable\sname.
+D 2009-09-26T17:51:48
 F Makefile.arm-wince-mingw32ce-gcc fcd5e9cd67fe88836360bb4f9ef4cb7f8e2fb5a0
 F Makefile.in 4ca3f1dd6efa2075bcb27f4dc43eef749877740d
 F Makefile.linux-gcc d53183f4aa6a9192d249731c90dbdffbd2c68654
@@ -99,7 +99,7 @@ F spec.template 86a4a43b99ebb3e75e6b9a735d5fd293a24e90ca
 F sqlite.pc.in 42b7bf0d02e08b9e77734a47798d1a55a9e0716b
 F sqlite3.1 6be1ad09113570e1fc8dcaff84c9b0b337db5ffc
 F sqlite3.pc.in ae6f59a76e862f5c561eb32a380228a02afc3cad
-F src/alter.c e771528da07315e0416bf9788399fb3dc2fecb5e
+F src/alter.c 082657ce3a584a512ed472e3163c09ed399e17f4
 F src/analyze.c 5a8b8aa3d170eac5e71af45458cec61f83c623ee
 F src/attach.c 13995348fc5a26cdd136a50806faf292aabc173f
 F src/auth.c d6a88bf8e81e6a079ccb8881002b327e42ec46b9
@@ -116,7 +116,7 @@ F src/date.c 657ff12ca0f1195b531561afacbb38b772d16638
 F src/delete.c 2a3d6fc0861b2f8dbd9feb7847b390267b281c60
 F src/expr.c c7f3f718bd5c392344ec8694a41c1824f30cf375
 F src/fault.c dc88c821842157460750d2d61a8a8b4197d047ff
-F src/fkey.c 542de974e3ed3a507f00b68d1486a4cbeaf4d8bb
+F src/fkey.c ee4e0d2465c2c092b2b6ab4be7e33ae33d6c6dac
 F src/func.c e536218d193b8d326aab91120bc4c6f28aa2b606
 F src/global.c 271952d199a8cc59d4ce840b3bbbfd2f30c8ba32
 F src/hash.c ebcaa921ffd9d86f7ea5ae16a0a29d1c871130a7
@@ -164,7 +164,7 @@ F src/select.c 1d0a13137532321b4364f964e46f057d271691e3
 F src/shell.c d6e64471aafb81f355262533393169a70529847a
 F src/sqlite.h.in 5af8181f815831a8672c3834c60e6b4418448bcc
 F src/sqlite3ext.h 1db7d63ab5de4b3e6b83dd03d1a4e64fef6d2a17
-F src/sqliteInt.h 7dcffff0e91ff07e3f7752c4d8e87f9582443a20
+F src/sqliteInt.h 21510d10a6794c633e044e8396acb7899396a9e8
 F src/sqliteLimit.h 504a3161886d2938cbd163054ad620b8356df758
 F src/status.c 237b193efae0cf6ac3f0817a208de6c6c6ef6d76
 F src/table.c cc86ad3d6ad54df7c63a3e807b5783c90411a08d
@@ -330,7 +330,7 @@ F test/expr.test 9f521ae22f00e074959f72ce2e55d46b9ed23f68
 F test/filectrl.test 8923a6dc7630f31c8a9dd3d3d740aa0922df7bf8
 F test/filefmt.test 84e3d0fe9f12d0d2ac852465c6f8450aea0d6f43
 F test/fkey1.test 01c7de578e11747e720c2d9aeef27f239853c4da
-F test/fkey2.test 4b22c954c3923ffe366feb664b33b1b438abb5b1
+F test/fkey2.test 13e99ef0cafe6947638f748aea7b1a7ee8aecb1a
 F test/fkey3.test 2183cac9075f3aae4875106eb9255bb73618444e
 F test/fkey_malloc.test da912d000bb6ceb1cd11b655de1989762fa71ceb
 F test/format4.test 1f0cac8ff3895e9359ed87e41aaabee982a812eb
@@ -755,7 +755,7 @@ F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P 9fd54b0aa73ed74c65f7db53cb666752f13263f9
-R 5e90fcf7b135a7c55fc18c54261d65ee
+P 519144ac437b5842e4213f0e81e05c709939c2ab
+R 67b182d615cf1918bbb959f1c1561217
 U dan
-Z 1aaee7b75a94b33f2eb5b3e61baf845b
+Z 1c73bf12a1b7498f5704501d82682485
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-519144ac437b5842e4213f0e81e05c709939c2ab
+b4a10c39e726dc190e9597e382baddc034294114
--- a/src/alter.c
+++ b/src/alter.c
@@ -85,6 +85,67 @@ static void renameTableFunc(
  }
 }

+/*
+** This C function implements an SQL user function that is used by SQL code
+** generated by the ALTER TABLE ... RENAME command to modify the definition
+** of any foreign key constraints that use the table being renamed as the 
+** parent table. It is passed three arguments:
+**
+**   1) The complete text of the CREATE TABLE statement being modified,
+**   2) The old name of the table being renamed, and
+**   3) The new name of the table being renamed.
+**
+** It returns the new CREATE TABLE statement. For example:
+**
+**   sqlite_rename_parent('CREATE TABLE t1(a REFERENCES t2)', 't2', 't3')
+**       -> 'CREATE TABLE t1(a REFERENCES t3)'
+*/
+#ifndef SQLITE_OMIT_FOREIGN_KEY
+static void renameParentFunc(
+  sqlite3_context *context,
+  int NotUsed,
+  sqlite3_value **argv
+){
+  sqlite3 *db = sqlite3_context_db_handle(context);
+  char *zOutput = 0;
+  char *zResult;
+  unsigned char const *zInput = sqlite3_value_text(argv[0]);
+  unsigned char const *zOld = sqlite3_value_text(argv[1]);
+  unsigned char const *zNew = sqlite3_value_text(argv[2]);
+
+  unsigned const char *z;         /* Pointer to token */
+  int n;                          /* Length of token z */
+  int token;                      /* Type of token */
+
+  for(z=zInput; *z; z=z+n){
+    n = sqlite3GetToken(z, &token);
+    if( token==TK_REFERENCES ){
+      char *zParent;
+      do {
+        z += n;
+        n = sqlite3GetToken(z, &token);
+      }while( token==TK_SPACE );
+
+      zParent = sqlite3DbStrNDup(db, (const char *)z, n);
+      sqlite3Dequote(zParent);
+      if( 0==sqlite3StrICmp((const char *)zOld, zParent) ){
+        char *zOut = sqlite3MPrintf(db, "%s%.*s\"%w\"", 
+            (zOutput?zOutput:""), z-zInput, zInput, (const char *)zNew
+        );
+        sqlite3DbFree(db, zOutput);
+        zOutput = zOut;
+        zInput = &z[n];
+      }
+      sqlite3DbFree(db, zParent);
+    }
+  }
+
+  zResult = sqlite3MPrintf(db, "%s%s", (zOutput?zOutput:""), zInput), 
+  sqlite3_result_text(context, zResult, -1, SQLITE_DYNAMIC);
+  sqlite3DbFree(db, zOutput);
+}
+#endif
+
 #ifndef SQLITE_OMIT_TRIGGER
 /* This function is used by SQL generated to implement the
 ** ALTER TABLE command. The first argument is the text of a CREATE TRIGGER 
@@ -172,6 +233,52 @@ void sqlite3AlterFunctions(sqlite3 *db){
  sqlite3CreateFunc(db, "sqlite_rename_trigger", 2, SQLITE_UTF8, 0,
                         renameTriggerFunc, 0, 0);
 #endif
+#ifndef SQLITE_OMIT_FOREIGN_KEY
+  sqlite3CreateFunc(db, "sqlite_rename_parent", 3, SQLITE_UTF8, 0,
+                         renameParentFunc, 0, 0);
+#endif
+}
+
+/*
+** This function is used to create the text of expressions of the form:
+**
+**   name=<constant1> OR name=<constant2> OR ...
+**
+** If argument zWhere is NULL, then a pointer string containing the text 
+** "name=<constant>" is returned, where <constant> is the quoted version
+** of the string passed as argument zConstant. The returned buffer is
+** allocated using sqlite3DbMalloc(). It is the responsibility of the
+** caller to ensure that it is eventually freed.
+**
+** If argument zWhere is not NULL, then the string returned is 
+** "<where> OR name=<constant>", where <where> is the contents of zWhere.
+** In this case zWhere is passed to sqlite3DbFree() before returning.
+** 
+*/
+static char *whereOrName(sqlite3 *db, char *zWhere, char *zConstant){
+  char *zNew;
+  if( !zWhere ){
+    zNew = sqlite3MPrintf(db, "name=%Q", zConstant);
+  }else{
+    zNew = sqlite3MPrintf(db, "%s OR name=%Q", zWhere, zConstant);
+    sqlite3DbFree(db, zWhere);
+  }
+  return zNew;
+}
+
+/*
+** Generate the text of a WHERE expression which can be used to select all
+** tables that have foreign key constraints that refer to table pTab (i.e.
+** constraints for which pTab is the parent table) from the sqlite_master
+** table.
+*/
+static char *whereForeignKeys(Parse *pParse, Table *pTab){
+  FKey *p;
+  char *zWhere = 0;
+  for(p=sqlite3FkReferences(pTab); p; p=p->pNextTo){
+    zWhere = whereOrName(pParse->db, zWhere, p->pFrom->zName);
+  }
+  return zWhere;
 }

 /*
@@ -183,7 +290,6 @@ void sqlite3AlterFunctions(sqlite3 *db){
 static char *whereTempTriggers(Parse *pParse, Table *pTab){
  Trigger *pTrig;
  char *zWhere = 0;
-  char *tmp = 0;
  const Schema *pTempSchema = pParse->db->aDb[1].pSchema; /* Temp db schema */

  /* If the table is not located in the temp-db (in which case NULL is 
@@ -195,13 +301,7 @@ static char *whereTempTriggers(Parse *pParse, Table *pTab){
    sqlite3 *db = pParse->db;
    for(pTrig=sqlite3TriggerList(pParse, pTab); pTrig; pTrig=pTrig->pNext){
      if( pTrig->pSchema==pTempSchema ){
-        if( !zWhere ){
-          zWhere = sqlite3MPrintf(db, "name=%Q", pTrig->zName);
-        }else{
-          tmp = zWhere;
-          zWhere = sqlite3MPrintf(db, "%s OR name=%Q", zWhere, pTrig->zName);
-          sqlite3DbFree(db, tmp);
-        }
+        zWhere = whereOrName(db, zWhere, pTrig->zName);
      }
    }
  }
@@ -239,7 +339,7 @@ static void reloadTableSchema(Parse *pParse, Table *pTab, const char *zName){
  }
 #endif

-  /* Drop the table and index from the internal schema */
+  /* Drop the table and index from the internal schema.  */
  sqlite3VdbeAddOp4(v, OP_DropTable, iDb, 0, 0, pTab->zName, 0);

  /* Reload the table, index and permanent trigger schemas. */
@@ -370,6 +470,21 @@ void sqlite3AlterRenameTable(
  zTabName = pTab->zName;
  nTabName = sqlite3Utf8CharLen(zTabName, -1);

+#ifndef SQLITE_OMIT_FOREIGN_KEY
+  if( db->flags&SQLITE_ForeignKeys ){
+    /* If foreign-key support is enabled, rewrite the CREATE TABLE 
+    ** statements corresponding to all child tables of foreign key constraints
+    ** for which the renamed table is the parent table.  */
+    if( (zWhere=whereForeignKeys(pParse, pTab))!=0 ){
+      sqlite3NestedParse(pParse, 
+          "UPDATE sqlite_master SET "
+              "sql = sqlite_rename_parent(sql, %Q, %Q) "
+              "WHERE %s;", zTabName, zName, zWhere);
+      sqlite3DbFree(db, zWhere);
+    }
+  }
+#endif
+
  /* Modify the sqlite_master table to use the new table name. */
  sqlite3NestedParse(pParse,
      "UPDATE %Q.%s SET "
@@ -421,6 +536,18 @@ void sqlite3AlterRenameTable(
  }
 #endif

+#ifndef SQLITE_OMIT_FOREIGN_KEY
+  if( db->flags&SQLITE_ForeignKeys ){
+    FKey *p;
+    for(p=sqlite3FkReferences(pTab); p; p=p->pNextTo){
+      Table *pFrom = p->pFrom;
+      if( pFrom!=pTab ){
+        reloadTableSchema(pParse, p->pFrom, pFrom->zName);
+      }
+    }
+  }
+#endif
+
  /* Drop and reload the internal table schema. */
  reloadTableSchema(pParse, pTab, zName);

--- a/src/fkey.c
+++ b/src/fkey.c
@@ -517,7 +517,7 @@ static void fkScanChildren(
 ** NULL pointer (as there are no FK constraints for which t2 is the parent
 ** table).
 */
-static FKey *fkRefering(Table *pTab){
+FKey *sqlite3FkReferences(Table *pTab){
  int nName = sqlite3Strlen30(pTab->zName);
  return (FKey *)sqlite3HashFind(&pTab->pSchema->fkeyHash, pTab->zName, nName);
 }
@@ -645,7 +645,7 @@ void sqlite3FkCheck(
  }

  /* Loop through all the foreign key constraints that refer to this table */
-  for(pFKey = fkRefering(pTab); pFKey; pFKey=pFKey->pNextTo){
+  for(pFKey = sqlite3FkReferences(pTab); pFKey; pFKey=pFKey->pNextTo){
    int iGoto;                    /* Address of OP_Goto instruction */
    Index *pIdx = 0;              /* Foreign key index for pFKey */
    SrcList *pSrc;
@@ -740,7 +740,7 @@ u32 sqlite3FkOldmask(
    for(p=pTab->pFKey; p; p=p->pNextFrom){
      for(i=0; i<p->nCol; i++) mask |= COLUMN_MASK(p->aCol[i].iFrom);
    }
-    for(p=fkRefering(pTab); p; p=p->pNextTo){
+    for(p=sqlite3FkReferences(pTab); p; p=p->pNextTo){
      Index *pIdx = 0;
      locateFkeyIndex(0, pTab, p, &pIdx, 0);
      if( pIdx ){
@@ -767,7 +767,7 @@ int sqlite3FkRequired(
  ExprList *pChanges              /* Non-NULL for UPDATE operations */
 ){
  if( pParse->db->flags&SQLITE_ForeignKeys ){
-    if( fkRefering(pTab) || pTab->pFKey ) return 1;
+    if( sqlite3FkReferences(pTab) || pTab->pFKey ) return 1;
  }
  return 0;
 }
@@ -968,7 +968,7 @@ void sqlite3FkActions(
  ** trigger sub-program.  */
  if( pParse->db->flags&SQLITE_ForeignKeys ){
    FKey *pFKey;                  /* Iterator variable */
-    for(pFKey = fkRefering(pTab); pFKey; pFKey=pFKey->pNextTo){
+    for(pFKey = sqlite3FkReferences(pTab); pFKey; pFKey=pFKey->pNextTo){
      Trigger *pAction = fkActionTrigger(pParse, pTab, pFKey, pChanges);
      if( pAction ){
        sqlite3CodeRowTriggerDirect(pParse, pAction, pTab, regOld, OE_Abort, 0);
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -2952,6 +2952,7 @@ VTable *sqlite3GetVTable(sqlite3*, Table*);
  void sqlite3FkActions(Parse*, Table*, ExprList*, int);
  int sqlite3FkRequired(Parse*, Table*, ExprList*);
  u32 sqlite3FkOldmask(Parse*, Table*, ExprList*);
+  FKey *sqlite3FkReferences(Table *);
 #else
  #define sqlite3FkCheck(a,b,c,d,e)
  #define sqlite3FkActions(a,b,c,d)
--- a/test/fkey2.test
+++ b/test/fkey2.test
@@ -804,6 +804,61 @@ do_test fkey2-14.1.6 {
  }
 } {{CREATE TABLE t2(a, b, c REFERENCES t1, d DEFAULT NULL REFERENCES t1, e REFERENCES t1 DEFAULT NULL, h DEFAULT 'text' REFERENCES t1)}}

+
+# Test the sqlite_rename_parent() function directly.
+#
+proc test_rename_parent {zCreate zOld zNew} {
+  db eval {SELECT sqlite_rename_parent($zCreate, $zOld, $zNew)}
+}
+do_test fkey2-14.2.1.1 {
+  test_rename_parent {CREATE TABLE t1(a REFERENCES t2)} t2 t3
+} {{CREATE TABLE t1(a REFERENCES "t3")}}
+do_test fkey2-14.2.1.2 {
+  test_rename_parent {CREATE TABLE t1(a REFERENCES t2)} t4 t3
+} {{CREATE TABLE t1(a REFERENCES t2)}}
+do_test fkey2-14.2.1.3 {
+  test_rename_parent {CREATE TABLE t1(a REFERENCES "t2")} t2 t3
+} {{CREATE TABLE t1(a REFERENCES "t3")}}
+
+# Test ALTER TABLE RENAME TABLE a bit.
+#
+do_test fkey2-14.2.2.1 {
+  drop_all_tables
+  execsql {
+    CREATE TABLE t1(a PRIMARY KEY, b REFERENCES t1);
+    CREATE TABLE t2(a PRIMARY KEY, b REFERENCES t1, c REFERENCES t2);
+    CREATE TABLE t3(a REFERENCES t1, b REFERENCES t2, c REFERENCES t1);
+  }
+  execsql { SELECT sql FROM sqlite_master WHERE type = 'table'}
+} [list \
+  {CREATE TABLE t1(a PRIMARY KEY, b REFERENCES t1)}                     \
+  {CREATE TABLE t2(a PRIMARY KEY, b REFERENCES t1, c REFERENCES t2)}    \
+  {CREATE TABLE t3(a REFERENCES t1, b REFERENCES t2, c REFERENCES t1)}  \
+]
+do_test fkey2-14.2.2.2 {
+  execsql { ALTER TABLE t1 RENAME TO t4 }
+  execsql { SELECT sql FROM sqlite_master WHERE type = 'table'}
+} [list \
+  {CREATE TABLE "t4"(a PRIMARY KEY, b REFERENCES "t4")}                     \
+  {CREATE TABLE t2(a PRIMARY KEY, b REFERENCES "t4", c REFERENCES t2)}    \
+  {CREATE TABLE t3(a REFERENCES "t4", b REFERENCES t2, c REFERENCES "t4")}  \
+]
+do_test fkey2-14.2.2.3 {
+  catchsql { INSERT INTO t3 VALUES(1, 2, 3) }
+} {1 {foreign key constraint failed}}
+do_test fkey2-14.2.2.4 {
+  execsql { INSERT INTO t4 VALUES(1, NULL) }
+} {}
+do_test fkey2-14.2.2.5 {
+  catchsql { UPDATE t4 SET b = 5 }
+} {1 {foreign key constraint failed}}
+do_test fkey2-14.2.2.6 {
+  catchsql { UPDATE t4 SET b = 1 }
+} {0 {}}
+do_test fkey2-14.2.2.7 {
+  execsql { INSERT INTO t3 VALUES(1, NULL, 1) }
+} {}
+
 #-------------------------------------------------------------------------
 # The following tests, fkey2-15.*, test that unnecessary FK related scans 
 # and lookups are avoided when the constraint counters are zero.