From: drh <>
Date: Fri, 1 Mar 2024 14:47:01 +0000 (+0000)
Subject: Improved handling of foreign-key constraints on a multi-drop of tables.
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=b0f953862844d3a71dfcea43e95d01e5b5ca7573;p=thirdparty%2Fsqlite.git

Improved handling of foreign-key constraints on a multi-drop of tables.

FossilOrigin-Name: 144e332f44b266a0e594f990088faccd1f0f08fe8e84f2efc9467d99fc14e84b
---

diff --git a/manifest b/manifest
index f8caa0c481..11489fae07 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C When\sdoing\sa\smulti-drop,\sdelete\sbtrees\sbeginning\swith\sthe\slargest\sroot\spage\nfirst\sand\sworking\stoward\ssmaller\sroot\spages,\sto\savoid\sproblems\swith\sroot\spage\nrenumbering\sdue\sto\sautovacuum.
-D 2024-03-01T12:21:45.438
+C Improved\shandling\sof\sforeign-key\sconstraints\son\sa\smulti-drop\sof\stables.
+D 2024-03-01T14:47:01.034
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -692,7 +692,7 @@ F src/btmutex.c 79a43670447eacc651519a429f6ece9fd638563cf95b469d6891185ddae2b522
 F src/btree.c 285b493d843e7ba8ef78b6ae7d31238e904901dbc0c484f7904de4cf18fd8802
 F src/btree.h 55066f513eb095db935169dab1dc2f7c7a747ef223c533f5d4ad4dfed346cbd0
 F src/btreeInt.h 98aadb6dcb77b012cab2574d6a728fad56b337fc946839b9898c4b4c969e30b6
-F src/build.c 39344791925e956a11ac74aca8d4ce3d34a5982e33a97bfea1b9a8ed8d5f995c
+F src/build.c 0beb76c2459701acb56522a385b444b408e99923908963ff0b7537bbcd8072f3
 F src/callback.c db3a45e376deff6a16c0058163fe0ae2b73a2945f3f408ca32cf74960b28d490
 F src/complete.c a3634ab1e687055cd002e11b8f43eb75c17da23e
 F src/ctime.c 23331529e654be40ca97d171cbbffe9b3d4c71cc53b78fe5501230675952da8b
@@ -702,7 +702,7 @@ F src/dbstat.c 3b677254d512fcafd4d0b341bf267b38b235ccfddbef24f9154e19360fa22e43
 F src/delete.c cb766727c78e715f9fb7ec8a7d03658ed2a3016343ca687acfcec9083cdca500
 F src/expr.c 2803f5e7e3458ced24c0de48ec3640cd7a68ec61350d99c9f30b1bcd6640bd61
 F src/fault.c 460f3e55994363812d9d60844b2a6de88826e007
-F src/fkey.c b7ecbc98b4da91d03e3435ca6abc167efa30f6691b090820969c4be625739e45
+F src/fkey.c 0592046ed7598625234298211cc1fe611efb3fe7870a3f1938038fd9092c82f9
 F src/func.c 4204c56196847faefef57fa14e43b8e4d65eb8d7e65318abe463472e3fd148cb
 F src/global.c 765a0656d6cbf043cb272ff0ae38f39cc46713539ffe6793258ed3eb4b188b52
 F src/hash.c 9ee4269fb1d6632a6fecfb9479c93a1f29271bddbbaf215dd60420bcb80c7220
@@ -755,7 +755,7 @@ F src/shell.c.in 2ec564ed3ff0147036be313efeb47b3dbfb8753d5eb5ea0e90636427c6b3a36
 F src/sqlite.h.in 19a2db3995a699bd7f6dfb423856242bfceb7ec849a93c91d241d19fc28d9f0f
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h 3f046c04ea3595d6bfda99b781926b17e672fd6d27da2ba6d8d8fc39981dcb54
-F src/sqliteInt.h d5101433f13bd5944472c1b4c28a2eaa198c9773f8c54496b57095b27289bfe9
+F src/sqliteInt.h cb537898d97cf63a910508c72b1156b9eab9d1b1f11653a5462f449f1ace55d1
 F src/sqliteLimit.h 6878ab64bdeb8c24a1d762d45635e34b96da21132179023338c93f820eee6728
 F src/status.c cb11f8589a6912af2da3bb1ec509a94dd8ef27df4d4c1a97e0bcf2309ece972b
 F src/table.c 0f141b58a16de7e2fbe81c308379e7279f4c6b50eb08efeec5892794a0ba30d1
@@ -2177,8 +2177,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 02f9fc73eef80f528097581580977aae46942baac2d7fb205c52f7f25472f2a8
-R 6e23b5efb65bccda72802397068f9d95
+P 37d4c5e207888b49c224275b05abfc1f63a2d8d2133bcc8970188b15387926ef
+R f9987f78741bf51eb98898493f5f3c5f
 U drh
-Z f617c5603de9e2495d967184783943a7
+Z b38468a9eeb68f1ed1b602a2a1e00e32
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index 087e4f307d..5c0f48d4dc 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-37d4c5e207888b49c224275b05abfc1f63a2d8d2133bcc8970188b15387926ef
\ No newline at end of file
+144e332f44b266a0e594f990088faccd1f0f08fe8e84f2efc9467d99fc14e84b
\ No newline at end of file
diff --git a/src/build.c b/src/build.c
index 9b2d808fe7..e476da1c4f 100644
--- a/src/build.c
+++ b/src/build.c
@@ -3589,7 +3589,7 @@ void sqlite3DropTable(Parse *pParse, SrcList *pName, int isView, int noErr){
     sqlite3BeginWriteOperation(pParse, 1, iDb);
     if( IsOrdinaryTable(pTab) ){
       sqlite3ClearStatTables(pParse, iDb, "tbl", pTab->zName);
-      sqlite3FkDropTable(pParse, &pName->a[ii], pTab);
+      sqlite3FkDropTable(pParse, pName, pTab);
     }
   }
 
diff --git a/src/fkey.c b/src/fkey.c
index 82c25b67da..9bdb555d7c 100644
--- a/src/fkey.c
+++ b/src/fkey.c
@@ -718,8 +718,9 @@ void sqlite3FkClearTriggerCache(sqlite3 *db, int iDb){
 /*
 ** This function is called to generate code that runs when table pTab is
 ** being dropped from the database. The SrcList passed as the second argument
-** to this function contains a single entry guaranteed to resolve to
-** table pTab.
+** to this function contains entries for every table that is being dropped,
+** with the SrcItem.pTab line being set to the table being dropped.  pTab
+** will be one of those tables.
 **
 ** Normally, no code is required. However, if either
 **
@@ -728,16 +729,23 @@ void sqlite3FkClearTriggerCache(sqlite3 *db, int iDb){
 **       determined at runtime that there are outstanding deferred FK 
 **       constraint violations in the database,
 **
-** then the equivalent of "DELETE FROM <tbl>" is executed before dropping
-** the table from the database. Triggers are disabled while running this
-** DELETE, but foreign key actions are not.
+** then the equivalent of "DELETE FROM <tbl>" is executed for every table
+** being dropped, in the order specified in the DROP TABLE statement, which
+** is the same as the order in which these tables appear in pName.
+** Triggers are disabled while running these DELETEs, but foreign key
+** actions are not.
+**
+** This routine sets the SrcList.addrFillSub value for all pName entries
+** for which DELETE FROM has been run.  This prevents the DELETE FROM
+** from being run multiple times.
 */
-void sqlite3FkDropTable(Parse *pParse, SrcItem *pName, Table *pTab){
+void sqlite3FkDropTable(Parse *pParse, SrcList *pName, Table *pTab){
   sqlite3 *db = pParse->db;
   if( (db->flags&SQLITE_ForeignKeys) && IsOrdinaryTable(pTab) ){
     int iSkip = 0;
     Vdbe *v = sqlite3GetVdbe(pParse);
     SrcList *pSrc;
+    int ii;
 
     assert( v );                  /* VDBE has already been allocated */
     assert( IsOrdinaryTable(pTab) );
@@ -757,11 +765,16 @@ void sqlite3FkDropTable(Parse *pParse, SrcItem *pName, Table *pTab){
     }
 
     pParse->disableTriggers = 1;
-    pSrc = sqlite3SrcListAppend(pParse, 0, 0, 0);
-    if( pSrc ){
-      pSrc->a[0].zDatabase = sqlite3DbStrDup(db, pName->zDatabase);
-      pSrc->a[0].zName = sqlite3DbStrDup(db, pName->zName);
-      sqlite3DeleteFrom(pParse, pSrc, 0, 0, 0);
+    for(ii=0; ii<pName->nSrc; ii++){
+      if( pName->a[ii].pTab==0 ) continue;
+      if( pName->a[ii].addrFillSub ) continue;
+      pName->a[ii].addrFillSub = 1;
+      pSrc = sqlite3SrcListAppend(pParse, 0, 0, 0);
+      if( pSrc ){
+        pSrc->a[0].zDatabase = sqlite3DbStrDup(db, pName->a[ii].zDatabase);
+        pSrc->a[0].zName = sqlite3DbStrDup(db, pName->a[ii].zName);
+        sqlite3DeleteFrom(pParse, pSrc, 0, 0, 0);
+      }
     }
     pParse->disableTriggers = 0;
 
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index f91f2d9ae3..fd80d2827a 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -5576,7 +5576,7 @@ const char *sqlite3JournalModename(int);
 */
 #if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
   void sqlite3FkCheck(Parse*, Table*, int, int, int*, int);
-  void sqlite3FkDropTable(Parse*, SrcItem*, Table*);
+  void sqlite3FkDropTable(Parse*, SrcList*, Table*);
   void sqlite3FkActions(Parse*, Table*, ExprList*, int, int*, int);
   int sqlite3FkRequired(Parse*, Table*, int*, int);
   u32 sqlite3FkOldmask(Parse*, Table*);