Add support for CREATE INDEX IF NOT EXISTS and DROP INDEX IF EXISTS. (CVS 2855)

FossilOrigin-Name: 551cdd6c309e75687abaeac5381b794cd5e4c10a

4 files changed, 22 insertions, 17 deletions

diff --git a/src/build.c b/src/build.c
index 655fee543..48cebe427 100644
--- a/src/build.c
+++ b/src/build.c
@@ -22,7 +22,7 @@
 **     COMMIT
 **     ROLLBACK
 **
-** $Id: build.c,v 1.364 2005/12/29 23:33:54 drh Exp $
+** $Id: build.c,v 1.365 2006/01/04 15:54:36 drh Exp $
 */
 #include "sqliteInt.h"
 #include <ctype.h>
@@ -1056,7 +1056,7 @@ void sqlite3AddPrimaryKey(
        "INTEGER PRIMARY KEY");
 #endif
   }else{
-    sqlite3CreateIndex(pParse, 0, 0, 0, pList, onError, 0, 0, sortOrder);
+    sqlite3CreateIndex(pParse, 0, 0, 0, pList, onError, 0, 0, sortOrder, 0);
     pList = 0;
   }
 
@@ -2105,7 +2105,8 @@ void sqlite3CreateIndex(
   int onError,       /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
   Token *pStart,     /* The CREATE token that begins a CREATE TABLE statement */
   Token *pEnd,       /* The ")" that closes the CREATE INDEX statement */
-  int sortOrder      /* Sort order of primary key when pList==NULL */
+  int sortOrder,     /* Sort order of primary key when pList==NULL */
+  int ifNotExist     /* Omit error if index already exists */
 ){
   Table *pTab = 0;     /* Table to be indexed */
   Index *pIndex = 0;   /* The index to be created */
@@ -2199,7 +2200,9 @@ void sqlite3CreateIndex(
     if( !db->init.busy ){
       if( SQLITE_OK!=sqlite3ReadSchema(pParse) ) goto exit_create_index;
       if( sqlite3FindIndex(db, zName, pDb->zName)!=0 ){
-        sqlite3ErrorMsg(pParse, "index %s already exists", zName);
+        if( !ifNotExist ){
+          sqlite3ErrorMsg(pParse, "index %s already exists", zName);
+        }
         goto exit_create_index;
       }
       if( sqlite3FindTable(db, zName, 0)!=0 ){
@@ -2525,7 +2528,7 @@ void sqlite3DefaultRowEst(Index *pIdx){
 ** This routine will drop an existing named index.  This routine
 ** implements the DROP INDEX statement.
 */
-void sqlite3DropIndex(Parse *pParse, SrcList *pName){
+void sqlite3DropIndex(Parse *pParse, SrcList *pName, int ifExists){
   Index *pIndex;
   Vdbe *v;
   sqlite3 *db = pParse->db;
@@ -2539,7 +2542,9 @@ void sqlite3DropIndex(Parse *pParse, SrcList *pName){
   }
   pIndex = sqlite3FindIndex(db, pName->a[0].zName, pName->a[0].zDatabase);
   if( pIndex==0 ){
-    sqlite3ErrorMsg(pParse, "no such index: %S", pName, 0);
+    if( !ifExists ){
+      sqlite3ErrorMsg(pParse, "no such index: %S", pName, 0);
+    }
     pParse->checkSchema = 1;
     goto exit_drop_index;
   }
diff --git a/src/parse.y b/src/parse.y
index 13005756b..e7d13e865 100644
--- a/src/parse.y
+++ b/src/parse.y
@@ -14,7 +14,7 @@
 ** the parser.  Lemon will also generate a header file containing
 ** numeric codes for all of the tokens.
 **
-** @(#) $Id: parse.y,v 1.190 2005/12/29 23:33:54 drh Exp $
+** @(#) $Id: parse.y,v 1.191 2006/01/04 15:54:36 drh Exp $
 */
 
 // All token codes are small integers with #defines that begin with "TK_"
@@ -262,7 +262,7 @@ ccons ::= NULL onconf.
 ccons ::= NOT NULL onconf(R).               {sqlite3AddNotNull(pParse, R);}
 ccons ::= PRIMARY KEY sortorder(Z) onconf(R) autoinc(I).
                                      {sqlite3AddPrimaryKey(pParse,0,R,I,Z);}
-ccons ::= UNIQUE onconf(R).          {sqlite3CreateIndex(pParse,0,0,0,0,R,0,0,0);}
+ccons ::= UNIQUE onconf(R).    {sqlite3CreateIndex(pParse,0,0,0,0,R,0,0,0,0);}
 ccons ::= CHECK LP expr(X) RP.       {sqlite3AddCheckConstraint(pParse,X);}
 ccons ::= REFERENCES nm(T) idxlist_opt(TA) refargs(R).
                                 {sqlite3CreateForeignKey(pParse,0,&T,TA,R);}
@@ -312,7 +312,7 @@ tcons ::= CONSTRAINT nm.
 tcons ::= PRIMARY KEY LP idxlist(X) autoinc(I) RP onconf(R).
                                          {sqlite3AddPrimaryKey(pParse,X,R,I,0);}
 tcons ::= UNIQUE LP idxlist(X) RP onconf(R).
-                                 {sqlite3CreateIndex(pParse,0,0,0,X,R,0,0,0);}
+                                 {sqlite3CreateIndex(pParse,0,0,0,X,R,0,0,0,0);}
 tcons ::= CHECK LP expr(E) RP onconf. {sqlite3AddCheckConstraint(pParse,E);}
 tcons ::= FOREIGN KEY LP idxlist(FA) RP
           REFERENCES nm(T) idxlist_opt(TA) refargs(R) defer_subclause_opt(D). {
@@ -836,12 +836,12 @@ expritem(A) ::= .                       {A = 0;}
 
 ///////////////////////////// The CREATE INDEX command ///////////////////////
 //
-cmd ::= CREATE(S) uniqueflag(U) INDEX nm(X) dbnm(D)
+cmd ::= CREATE(S) uniqueflag(U) INDEX ifnotexists(NE) nm(X) dbnm(D)
         ON nm(Y) LP idxlist(Z) RP(E) onconf(R). {
   if( U!=OE_None ) U = R;
   if( U==OE_Default) U = OE_Abort;
   sqlite3CreateIndex(pParse, &X, &D, sqlite3SrcListAppend(0,&Y,0), Z, U,
-                      &S, &E, SQLITE_SO_ASC);
+                      &S, &E, SQLITE_SO_ASC, NE);
 }
 
 %type uniqueflag {int}
@@ -879,7 +879,7 @@ idxitem(A) ::= nm(X).              {A = X;}
 
 ///////////////////////////// The DROP INDEX command /////////////////////////
 //
-cmd ::= DROP INDEX fullname(X).   {sqlite3DropIndex(pParse, X);}
+cmd ::= DROP INDEX ifexists(E) fullname(X).   {sqlite3DropIndex(pParse, X, E);}
 
 ///////////////////////////// The VACUUM command /////////////////////////////
 //
diff --git a/src/prepare.c b/src/prepare.c
index 164c4149e..1510b344e 100644
--- a/src/prepare.c
+++ b/src/prepare.c
@@ -13,7 +13,7 @@
 ** interface, and routines that contribute to loading the database schema
 ** from disk.
 **
-** $Id: prepare.c,v 1.11 2005/12/29 19:23:07 drh Exp $
+** $Id: prepare.c,v 1.12 2006/01/04 15:54:36 drh Exp $
 */
 #include "sqliteInt.h"
 #include "os.h"
@@ -433,7 +433,7 @@ int sqlite3_prepare(
     sParse.rc = SQLITE_NOMEM;
   }
   if( sParse.rc==SQLITE_DONE ) sParse.rc = SQLITE_OK;
-  if( sParse.rc!=SQLITE_OK && sParse.checkSchema && !schemaIsValid(db) ){
+  if( sParse.checkSchema && !schemaIsValid(db) ){
     sParse.rc = SQLITE_SCHEMA;
   }
   if( sParse.rc==SQLITE_SCHEMA ){
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index f735aa408..7c30a5eec 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -11,7 +11,7 @@
 *************************************************************************
 ** Internal interface definitions for SQLite.
 **
-** @(#) $Id: sqliteInt.h,v 1.446 2005/12/30 16:28:02 danielk1977 Exp $
+** @(#) $Id: sqliteInt.h,v 1.447 2006/01/04 15:54:36 drh Exp $
 */
 #ifndef _SQLITEINT_H_
 #define _SQLITEINT_H_
@@ -1516,8 +1516,8 @@ void sqlite3SrcListAssignCursors(Parse*, SrcList*);
 void sqlite3IdListDelete(IdList*);
 void sqlite3SrcListDelete(SrcList*);
 void sqlite3CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,
-                        Token*, int);
-void sqlite3DropIndex(Parse*, SrcList*);
+                        Token*, int, int);
+void sqlite3DropIndex(Parse*, SrcList*, int);
 void sqlite3AddKeyType(Vdbe*, ExprList*);
 void sqlite3AddIdxKeyType(Vdbe*, Index*);
 int sqlite3Select(Parse*, Select*, int, int, Select*, int, int*, char *aff);