--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/engine/sqlite/src/alter.cpp Thu Feb 25 14:29:19 2010 +0000
@@ -0,0 +1,629 @@
+/*
+** 2005 February 15
+**
+** The author disclaims copyright to this source code. In place of
+** a legal notice, here is a blessing:
+**
+** May you do good and not evil.
+** May you find forgiveness for yourself and forgive others.
+** May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains C code routines that used to generate VDBE code
+** that implements the ALTER TABLE command.
+**
+** $Id: alter.cpp 1282 2008-11-13 09:31:33Z LarsPson $
+*/
+#include "sqliteInt.h"
+#include <ctype.h>
+
+/*
+** The code in this file only exists if we are not omitting the
+** ALTER TABLE logic from the build.
+*/
+#ifndef SQLITE_OMIT_ALTERTABLE
+
+
+/*
+** This function is used by SQL generated to implement the
+** ALTER TABLE command. The first argument is the text of a CREATE TABLE or
+** CREATE INDEX command. The second is a table name. The table name in
+** the CREATE TABLE or CREATE INDEX statement is replaced with the third
+** argument and the result returned. Examples:
+**
+** sqlite_rename_table('CREATE TABLE abc(a, b, c)', 'def')
+** -> 'CREATE TABLE def(a, b, c)'
+**
+** sqlite_rename_table('CREATE INDEX i ON abc(a)', 'def')
+** -> 'CREATE INDEX i ON def(a, b, c)'
+*/
+static void renameTableFunc(
+ sqlite3_context *context,
+ int argc,
+ sqlite3_value **argv
+){
+ unsigned char const *zSql = sqlite3_value_text(argv[0]);
+ unsigned char const *zTableName = sqlite3_value_text(argv[1]);
+
+ int token;
+ Token tname;
+ unsigned char const *zCsr = zSql;
+ int len = 0;
+ char *zRet;
+
+ sqlite3 *db = (sqlite3 *)sqlite3_user_data(context);
+
+ /* The principle used to locate the table name in the CREATE TABLE
+ ** statement is that the table name is the first token that is immediatedly
+ ** followed by a left parenthesis - TK_LP - or "USING" TK_USING.
+ */
+ if( zSql ){
+ do {
+ if( !*zCsr ){
+ /* Ran out of input before finding an opening bracket. Return NULL. */
+ return;
+ }
+
+ /* Store the token that zCsr points to in tname. */
+ tname.z = zCsr;
+ tname.n = len;
+
+ /* Advance zCsr to the next token. Store that token type in 'token',
+ ** and its length in 'len' (to be used next iteration of this loop).
+ */
+ do {
+ zCsr += len;
+ len = sqlite3GetToken(zCsr, &token);
+ } while( token==TK_SPACE );
+ assert( len>0 );
+ } while( token!=TK_LP && token!=TK_USING );
+
+ zRet = sqlite3MPrintf(db, "%.*s%Q%s", tname.z - zSql, zSql,
+ zTableName, tname.z+tname.n);
+ sqlite3_result_text(context, zRet, -1, sqlite3_free);
+ }
+}
+
+#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
+** statement. The second is a table name. The table name in the CREATE
+** TRIGGER statement is replaced with the third argument and the result
+** returned. This is analagous to renameTableFunc() above, except for CREATE
+** TRIGGER, not CREATE INDEX and CREATE TABLE.
+*/
+static void renameTriggerFunc(
+ sqlite3_context *context,
+ int argc,
+ sqlite3_value **argv
+){
+ unsigned char const *zSql = sqlite3_value_text(argv[0]);
+ unsigned char const *zTableName = sqlite3_value_text(argv[1]);
+
+ int token;
+ Token tname;
+ int dist = 3;
+ unsigned char const *zCsr = zSql;
+ int len = 0;
+ char *zRet;
+
+ sqlite3 *db = (sqlite3 *)sqlite3_user_data(context);
+
+ /* The principle used to locate the table name in the CREATE TRIGGER
+ ** statement is that the table name is the first token that is immediatedly
+ ** preceded by either TK_ON or TK_DOT and immediatedly followed by one
+ ** of TK_WHEN, TK_BEGIN or TK_FOR.
+ */
+ if( zSql ){
+ do {
+
+ if( !*zCsr ){
+ /* Ran out of input before finding the table name. Return NULL. */
+ return;
+ }
+
+ /* Store the token that zCsr points to in tname. */
+ tname.z = zCsr;
+ tname.n = len;
+
+ /* Advance zCsr to the next token. Store that token type in 'token',
+ ** and its length in 'len' (to be used next iteration of this loop).
+ */
+ do {
+ zCsr += len;
+ len = sqlite3GetToken(zCsr, &token);
+ }while( token==TK_SPACE );
+ assert( len>0 );
+
+ /* Variable 'dist' stores the number of tokens read since the most
+ ** recent TK_DOT or TK_ON. This means that when a WHEN, FOR or BEGIN
+ ** token is read and 'dist' equals 2, the condition stated above
+ ** to be met.
+ **
+ ** Note that ON cannot be a database, table or column name, so
+ ** there is no need to worry about syntax like
+ ** "CREATE TRIGGER ... ON ON.ON BEGIN ..." etc.
+ */
+ dist++;
+ if( token==TK_DOT || token==TK_ON ){
+ dist = 0;
+ }
+ } while( dist!=2 || (token!=TK_WHEN && token!=TK_FOR && token!=TK_BEGIN) );
+
+ /* Variable tname now contains the token that is the old table-name
+ ** in the CREATE TRIGGER statement.
+ */
+ zRet = sqlite3MPrintf(db, "%.*s%Q%s", tname.z - zSql, zSql,
+ zTableName, tname.z+tname.n);
+ sqlite3_result_text(context, zRet, -1, sqlite3_free);
+ }
+}
+#endif /* !SQLITE_OMIT_TRIGGER */
+
+/*
+** Register built-in functions used to help implement ALTER TABLE
+*/
+void sqlite3AlterFunctions(sqlite3 *db){
+ static const struct {
+ char *zName;
+ signed char nArg;
+ void (*xFunc)(sqlite3_context*,int,sqlite3_value **);
+ } aFuncs[] = {
+ { "sqlite_rename_table", 2, renameTableFunc},
+#ifndef SQLITE_OMIT_TRIGGER
+ { "sqlite_rename_trigger", 2, renameTriggerFunc},
+#endif
+ };
+ int i;
+
+ for(i=0; i<sizeof(aFuncs)/sizeof(aFuncs[0]); i++){
+ sqlite3CreateFunc(db, aFuncs[i].zName, aFuncs[i].nArg,
+ SQLITE_UTF8, (void *)db, aFuncs[i].xFunc, 0, 0);
+ }
+}
+
+/*
+** Generate the text of a WHERE expression which can be used to select all
+** temporary triggers on table pTab from the sqlite_temp_master table. If
+** table pTab has no temporary triggers, or is itself stored in the
+** temporary database, NULL is returned.
+*/
+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
+ ** returned, loop through the tables list of triggers. For each trigger
+ ** that is not part of the temp-db schema, add a clause to the WHERE
+ ** expression being built up in zWhere.
+ */
+ if( pTab->pSchema!=pTempSchema ){
+ sqlite3 *db = pParse->db;
+ for( pTrig=pTab->pTrigger; pTrig; pTrig=pTrig->pNext ){
+ if( pTrig->pSchema==pTempSchema ){
+ if( !zWhere ){
+ zWhere = sqlite3MPrintf(db, "name=%Q", pTrig->name);
+ }else{
+ tmp = zWhere;
+ zWhere = sqlite3MPrintf(db, "%s OR name=%Q", zWhere, pTrig->name);
+ sqlite3_free(tmp);
+ }
+ }
+ }
+ }
+ return zWhere;
+}
+
+/*
+** Generate code to drop and reload the internal representation of table
+** pTab from the database, including triggers and temporary triggers.
+** Argument zName is the name of the table in the database schema at
+** the time the generated code is executed. This can be different from
+** pTab->zName if this function is being called to code part of an
+** "ALTER TABLE RENAME TO" statement.
+*/
+static void reloadTableSchema(Parse *pParse, Table *pTab, const char *zName){
+ Vdbe *v;
+ char *zWhere;
+ int iDb; /* Index of database containing pTab */
+#ifndef SQLITE_OMIT_TRIGGER
+ Trigger *pTrig;
+#endif
+
+ v = sqlite3GetVdbe(pParse);
+ if( !v ) return;
+ assert( sqlite3BtreeHoldsAllMutexes(pParse->db) );
+ iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
+ assert( iDb>=0 );
+
+#ifndef SQLITE_OMIT_TRIGGER
+ /* Drop any table triggers from the internal schema. */
+ for(pTrig=pTab->pTrigger; pTrig; pTrig=pTrig->pNext){
+ int iTrigDb = sqlite3SchemaToIndex(pParse->db, pTrig->pSchema);
+ assert( iTrigDb==iDb || iTrigDb==1 );
+ sqlite3VdbeOp3(v, OP_DropTrigger, iTrigDb, 0, pTrig->name, 0);
+ }
+#endif
+
+ /* Drop the table and index from the internal schema */
+ sqlite3VdbeOp3(v, OP_DropTable, iDb, 0, pTab->zName, 0);
+
+ /* Reload the table, index and permanent trigger schemas. */
+ zWhere = sqlite3MPrintf(pParse->db, "tbl_name=%Q", zName);
+ if( !zWhere ) return;
+ sqlite3VdbeOp3(v, OP_ParseSchema, iDb, 0, zWhere, P3_DYNAMIC);
+
+#ifndef SQLITE_OMIT_TRIGGER
+ /* Now, if the table is not stored in the temp database, reload any temp
+ ** triggers. Don't use IN(...) in case SQLITE_OMIT_SUBQUERY is defined.
+ */
+ if( (zWhere=whereTempTriggers(pParse, pTab))!=0 ){
+ sqlite3VdbeOp3(v, OP_ParseSchema, 1, 0, zWhere, P3_DYNAMIC);
+ }
+#endif
+}
+
+/*
+** Generate code to implement the "ALTER TABLE xxx RENAME TO yyy"
+** command.
+*/
+void sqlite3AlterRenameTable(
+ Parse *pParse, /* Parser context. */
+ SrcList *pSrc, /* The table to rename. */
+ Token *pName /* The new table name. */
+){
+ int iDb; /* Database that contains the table */
+ char *zDb; /* Name of database iDb */
+ Table *pTab; /* Table being renamed */
+ char *zName = 0; /* NULL-terminated version of pName */
+ sqlite3 *db = pParse->db; /* Database connection */
+ int nTabName; /* Number of UTF-8 characters in zTabName */
+ const char *zTabName; /* Original name of the table */
+ Vdbe *v;
+#ifndef SQLITE_OMIT_TRIGGER
+ char *zWhere = 0; /* Where clause to locate temp triggers */
+#endif
+ int isVirtualRename = 0; /* True if this is a v-table with an xRename() */
+
+ if( db->mallocFailed ) goto exit_rename_table;
+ assert( pSrc->nSrc==1 );
+ assert( sqlite3BtreeHoldsAllMutexes(pParse->db) );
+
+ pTab = sqlite3LocateTable(pParse, pSrc->a[0].zName, pSrc->a[0].zDatabase);
+ if( !pTab ) goto exit_rename_table;
+ iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema);
+ zDb = db->aDb[iDb].zName;
+
+ /* Get a NULL terminated version of the new table name. */
+ zName = sqlite3NameFromToken(db, pName);
+ if( !zName ) goto exit_rename_table;
+
+ /* Check that a table or index named 'zName' does not already exist
+ ** in database iDb. If so, this is an error.
+ */
+ if( sqlite3FindTable(db, zName, zDb) || sqlite3FindIndex(db, zName, zDb) ){
+ sqlite3ErrorMsg(pParse,
+ "there is already another table or index with this name: %s", zName);
+ goto exit_rename_table;
+ }
+
+ /* Make sure it is not a system table being altered, or a reserved name
+ ** that the table is being renamed to.
+ */
+ if( strlen(pTab->zName)>6 && 0==sqlite3StrNICmp(pTab->zName, "sqlite_", 7) ){
+ sqlite3ErrorMsg(pParse, "table %s may not be altered", pTab->zName);
+ goto exit_rename_table;
+ }
+ if( SQLITE_OK!=sqlite3CheckObjectName(pParse, zName) ){
+ goto exit_rename_table;
+ }
+
+#ifndef SQLITE_OMIT_VIEW
+ if( pTab->pSelect ){
+ sqlite3ErrorMsg(pParse, "view %s may not be altered", pTab->zName);
+ goto exit_rename_table;
+ }
+#endif
+
+#ifndef SQLITE_OMIT_AUTHORIZATION
+ /* Invoke the authorization callback. */
+ if( sqlite3AuthCheck(pParse, SQLITE_ALTER_TABLE, zDb, pTab->zName, 0) ){
+ goto exit_rename_table;
+ }
+#endif
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+ if( sqlite3ViewGetColumnNames(pParse, pTab) ){
+ goto exit_rename_table;
+ }
+ if( IsVirtual(pTab) && pTab->pMod->pModule->xRename ){
+ isVirtualRename = 1;
+ }
+#endif
+
+ /* Begin a transaction and code the VerifyCookie for database iDb.
+ ** Then modify the schema cookie (since the ALTER TABLE modifies the
+ ** schema). Open a statement transaction if the table is a virtual
+ ** table.
+ */
+ v = sqlite3GetVdbe(pParse);
+ if( v==0 ){
+ goto exit_rename_table;
+ }
+ sqlite3BeginWriteOperation(pParse, isVirtualRename, iDb);
+ sqlite3ChangeCookie(db, v, iDb);
+
+ /* If this is a virtual table, invoke the xRename() function if
+ ** one is defined. The xRename() callback will modify the names
+ ** of any resources used by the v-table implementation (including other
+ ** SQLite tables) that are identified by the name of the virtual table.
+ */
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+ if( isVirtualRename ){
+ sqlite3VdbeOp3(v, OP_String8, 0, 0, zName, 0);
+ sqlite3VdbeOp3(v, OP_VRename, 0, 0, (const char*)pTab->pVtab, P3_VTAB);
+ }
+#endif
+
+ /* figure out how many UTF-8 characters are in zName */
+ zTabName = pTab->zName;
+ nTabName = sqlite3Utf8CharLen(zTabName, -1);
+
+ /* Modify the sqlite_master table to use the new table name. */
+ sqlite3NestedParse(pParse,
+ "UPDATE %Q.%s SET "
+#ifdef SQLITE_OMIT_TRIGGER
+ "sql = sqlite_rename_table(sql, %Q), "
+#else
+ "sql = CASE "
+ "WHEN type = 'trigger' THEN sqlite_rename_trigger(sql, %Q)"
+ "ELSE sqlite_rename_table(sql, %Q) END, "
+#endif
+ "tbl_name = %Q, "
+ "name = CASE "
+ "WHEN type='table' THEN %Q "
+ "WHEN name LIKE 'sqlite_autoindex%%' AND type='index' THEN "
+ "'sqlite_autoindex_' || %Q || substr(name,%d+18) "
+ "ELSE name END "
+ "WHERE tbl_name=%Q AND "
+ "(type='table' OR type='index' OR type='trigger');",
+ zDb, SCHEMA_TABLE(iDb), zName, zName, zName,
+#ifndef SQLITE_OMIT_TRIGGER
+ zName,
+#endif
+ zName, nTabName, zTabName
+ );
+
+#ifndef SQLITE_OMIT_AUTOINCREMENT
+ /* If the sqlite_sequence table exists in this database, then update
+ ** it with the new table name.
+ */
+ if( sqlite3FindTable(db, "sqlite_sequence", zDb) ){
+ sqlite3NestedParse(pParse,
+ "UPDATE %Q.sqlite_sequence set name = %Q WHERE name = %Q",
+ zDb, zName, pTab->zName);
+ }
+#endif
+
+#ifndef SQLITE_OMIT_TRIGGER
+ /* If there are TEMP triggers on this table, modify the sqlite_temp_master
+ ** table. Don't do this if the table being ALTERed is itself located in
+ ** the temp database.
+ */
+ if( (zWhere=whereTempTriggers(pParse, pTab))!=0 ){
+ sqlite3NestedParse(pParse,
+ "UPDATE sqlite_temp_master SET "
+ "sql = sqlite_rename_trigger(sql, %Q), "
+ "tbl_name = %Q "
+ "WHERE %s;", zName, zName, zWhere);
+ sqlite3_free(zWhere);
+ }
+#endif
+
+ /* Drop and reload the internal table schema. */
+ reloadTableSchema(pParse, pTab, zName);
+
+exit_rename_table:
+ sqlite3SrcListDelete(pSrc);
+ sqlite3_free(zName);
+}
+
+
+/*
+** This function is called after an "ALTER TABLE ... ADD" statement
+** has been parsed. Argument pColDef contains the text of the new
+** column definition.
+**
+** The Table structure pParse->pNewTable was extended to include
+** the new column during parsing.
+*/
+void sqlite3AlterFinishAddColumn(Parse *pParse, Token *pColDef){
+ Table *pNew; /* Copy of pParse->pNewTable */
+ Table *pTab; /* Table being altered */
+ int iDb; /* Database number */
+ const char *zDb; /* Database name */
+ const char *zTab; /* Table name */
+ char *zCol; /* Null-terminated column definition */
+ Column *pCol; /* The new column */
+ Expr *pDflt; /* Default value for the new column */
+ sqlite3 *db; /* The database connection; */
+
+ if( pParse->nErr ) return;
+ pNew = pParse->pNewTable;
+ assert( pNew );
+
+ db = pParse->db;
+ assert( sqlite3BtreeHoldsAllMutexes(db) );
+ iDb = sqlite3SchemaToIndex(db, pNew->pSchema);
+ zDb = db->aDb[iDb].zName;
+ zTab = pNew->zName;
+ pCol = &pNew->aCol[pNew->nCol-1];
+ pDflt = pCol->pDflt;
+ pTab = sqlite3FindTable(db, zTab, zDb);
+ assert( pTab );
+
+#ifndef SQLITE_OMIT_AUTHORIZATION
+ /* Invoke the authorization callback. */
+ if( sqlite3AuthCheck(pParse, SQLITE_ALTER_TABLE, zDb, pTab->zName, 0) ){
+ return;
+ }
+#endif
+
+ /* If the default value for the new column was specified with a
+ ** literal NULL, then set pDflt to 0. This simplifies checking
+ ** for an SQL NULL default below.
+ */
+ if( pDflt && pDflt->op==TK_NULL ){
+ pDflt = 0;
+ }
+
+ /* Check that the new column is not specified as PRIMARY KEY or UNIQUE.
+ ** If there is a NOT NULL constraint, then the default value for the
+ ** column must not be NULL.
+ */
+ if( pCol->isPrimKey ){
+ sqlite3ErrorMsg(pParse, "Cannot add a PRIMARY KEY column");
+ return;
+ }
+ if( pNew->pIndex ){
+ sqlite3ErrorMsg(pParse, "Cannot add a UNIQUE column");
+ return;
+ }
+ if( pCol->notNull && !pDflt ){
+ sqlite3ErrorMsg(pParse,
+ "Cannot add a NOT NULL column with default value NULL");
+ return;
+ }
+
+ /* Ensure the default expression is something that sqlite3ValueFromExpr()
+ ** can handle (i.e. not CURRENT_TIME etc.)
+ */
+ if( pDflt ){
+ sqlite3_value *pVal;
+ if( sqlite3ValueFromExpr(db, pDflt, SQLITE_UTF8, SQLITE_AFF_NONE, &pVal) ){
+ db->mallocFailed = 1;
+ return;
+ }
+ if( !pVal ){
+ sqlite3ErrorMsg(pParse, "Cannot add a column with non-constant default");
+ return;
+ }
+ sqlite3ValueFree(pVal);
+ }
+
+ /* Modify the CREATE TABLE statement. */
+ zCol = sqlite3DbStrNDup(db, (char*)pColDef->z, pColDef->n);
+ if( zCol ){
+ char *zEnd = &zCol[pColDef->n-1];
+ while( (zEnd>zCol && *zEnd==';') || isspace(*(unsigned char *)zEnd) ){
+ *zEnd-- = '\0';
+ }
+ sqlite3NestedParse(pParse,
+ "UPDATE %Q.%s SET "
+ "sql = substr(sql,1,%d) || ', ' || %Q || substr(sql,%d) "
+ "WHERE type = 'table' AND name = %Q",
+ zDb, SCHEMA_TABLE(iDb), pNew->addColOffset, zCol, pNew->addColOffset+1,
+ zTab
+ );
+ sqlite3_free(zCol);
+ }
+
+ /* If the default value of the new column is NULL, then set the file
+ ** format to 2. If the default value of the new column is not NULL,
+ ** the file format becomes 3.
+ */
+ sqlite3MinimumFileFormat(pParse, iDb, pDflt ? 3 : 2);
+
+ /* Reload the schema of the modified table. */
+ reloadTableSchema(pParse, pTab, pTab->zName);
+}
+
+/*
+** This function is called by the parser after the table-name in
+** an "ALTER TABLE <table-name> ADD" statement is parsed. Argument
+** pSrc is the full-name of the table being altered.
+**
+** This routine makes a (partial) copy of the Table structure
+** for the table being altered and sets Parse.pNewTable to point
+** to it. Routines called by the parser as the column definition
+** is parsed (i.e. sqlite3AddColumn()) add the new Column data to
+** the copy. The copy of the Table structure is deleted by tokenize.c
+** after parsing is finished.
+**
+** Routine sqlite3AlterFinishAddColumn() will be called to complete
+** coding the "ALTER TABLE ... ADD" statement.
+*/
+void sqlite3AlterBeginAddColumn(Parse *pParse, SrcList *pSrc){
+ Table *pNew;
+ Table *pTab;
+ Vdbe *v;
+ int iDb;
+ int i;
+ int nAlloc;
+ sqlite3 *db = pParse->db;
+
+ /* Look up the table being altered. */
+ assert( pParse->pNewTable==0 );
+ assert( sqlite3BtreeHoldsAllMutexes(db) );
+ if( db->mallocFailed ) goto exit_begin_add_column;
+ pTab = sqlite3LocateTable(pParse, pSrc->a[0].zName, pSrc->a[0].zDatabase);
+ if( !pTab ) goto exit_begin_add_column;
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+ if( IsVirtual(pTab) ){
+ sqlite3ErrorMsg(pParse, "virtual tables may not be altered");
+ goto exit_begin_add_column;
+ }
+#endif
+
+ /* Make sure this is not an attempt to ALTER a view. */
+ if( pTab->pSelect ){
+ sqlite3ErrorMsg(pParse, "Cannot add a column to a view");
+ goto exit_begin_add_column;
+ }
+
+ assert( pTab->addColOffset>0 );
+ iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+
+ /* Put a copy of the Table struct in Parse.pNewTable for the
+ ** sqlite3AddColumn() function and friends to modify.
+ */
+ pNew = (Table*)sqlite3DbMallocZero(db, sizeof(Table));
+ if( !pNew ) goto exit_begin_add_column;
+ pParse->pNewTable = pNew;
+ pNew->nRef = 1;
+ pNew->nCol = pTab->nCol;
+ assert( pNew->nCol>0 );
+ nAlloc = (((pNew->nCol-1)/8)*8)+8;
+ assert( nAlloc>=pNew->nCol && nAlloc%8==0 && nAlloc-pNew->nCol<8 );
+ pNew->aCol = (Column*)sqlite3DbMallocZero(db, sizeof(Column)*nAlloc);
+ pNew->zName = sqlite3DbStrDup(db, pTab->zName);
+ if( !pNew->aCol || !pNew->zName ){
+ db->mallocFailed = 1;
+ goto exit_begin_add_column;
+ }
+ memcpy(pNew->aCol, pTab->aCol, sizeof(Column)*pNew->nCol);
+ for(i=0; i<pNew->nCol; i++){
+ Column *pCol = &pNew->aCol[i];
+ pCol->zName = sqlite3DbStrDup(db, pCol->zName);
+ pCol->zColl = 0;
+ pCol->zType = 0;
+ pCol->pDflt = 0;
+ }
+ pNew->pSchema = db->aDb[iDb].pSchema;
+ pNew->addColOffset = pTab->addColOffset;
+ pNew->nRef = 1;
+
+ /* Begin a transaction and increment the schema cookie. */
+ sqlite3BeginWriteOperation(pParse, 0, iDb);
+ v = sqlite3GetVdbe(pParse);
+ if( !v ) goto exit_begin_add_column;
+ sqlite3ChangeCookie(db, v, iDb);
+
+exit_begin_add_column:
+ sqlite3SrcListDelete(pSrc);
+ return;
+}
+#endif /* SQLITE_ALTER_TABLE */