wasCSharpSQLite – Rev 1
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using System;
using System.Diagnostics;
using System.Text;
namespace Community.CsharpSqlite
{
using sqlite3_value = Sqlite3.Mem;
public partial class Sqlite3
{
/*
** 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.
*************************************************************************
** Included in SQLite3 port to C#-SQLite; 2008 Noah B Hart
** C#-SQLite is an independent reimplementation of the SQLite software library
**
** SQLITE_SOURCE_ID: 2011-06-23 19:49:22 4374b7e83ea0a3fbc3691f9c0c936272862f32f2
**
*************************************************************************
*/
//#include "sqliteInt.h"
/*
** The code in this file only exists if we are not omitting the
** ALTER TABLE logic from the build.
*/
#if !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 NotUsed,
sqlite3_value[] argv
)
{
string bResult = sqlite3_value_text( argv[0] );
string zSql = bResult ?? string.Empty;
string zTableName = sqlite3_value_text( argv[1] );
int token = 0;
Token tname = new Token();
int zCsr = 0;
int zLoc = 0;
int len = 0;
string zRet;
sqlite3 db = sqlite3_context_db_handle( context );
UNUSED_PARAMETER( NotUsed );
/* The principle used to locate the table name in the CREATE TABLE
** statement is that the table name is the first non-space token that
** is immediately followed by a TK_LP or TK_USING token.
*/
if ( zSql.Length > 0 )
{
do
{
if ( zCsr == zSql.Length )
{
/* Ran out of input before finding an opening bracket. Return NULL. */
return;
}
/* Store the token that zCsr points to in tname. */
zLoc = zCsr;
tname.z = zSql.Substring( zCsr );//(char*)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 = ( zCsr == zSql.Length ) ? 1 : sqlite3GetToken( zSql, zCsr, ref token );
} while ( token == TK_SPACE );
Debug.Assert( len > 0 );
} while ( token != TK_LP && token != TK_USING );
zRet = sqlite3MPrintf( db, "%.*s\"%w\"%s", zLoc, zSql.Substring( 0, zLoc ),
zTableName, zSql.Substring( zLoc + tname.n ) );
sqlite3_result_text( context, zRet, -1, SQLITE_DYNAMIC );
}
}
/*
** 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)'
*/
#if !SQLITE_OMIT_FOREIGN_KEY
static void renameParentFunc(
sqlite3_context context,
int NotUsed,
sqlite3_value[] argv
)
{
sqlite3 db = sqlite3_context_db_handle( context );
string zOutput = string.Empty;
string zResult;
string zInput = sqlite3_value_text( argv[0] );
string zOld = sqlite3_value_text( argv[1] );
string zNew = sqlite3_value_text( argv[2] );
int zIdx; /* Pointer to token */
int zLeft = 0; /* Pointer to remainder of String */
int n = 0; /* Length of token z */
int token = 0; /* Type of token */
UNUSED_PARAMETER( NotUsed );
for ( zIdx = 0; zIdx < zInput.Length; zIdx += n )//z=zInput; *z; z=z+n)
{
n = sqlite3GetToken( zInput, zIdx, ref token );
if ( token == TK_REFERENCES )
{
string zParent;
do
{
zIdx += n;
n = sqlite3GetToken( zInput, zIdx, ref token );
} while ( token == TK_SPACE );
zParent = zIdx + n < zInput.Length ? zInput.Substring( zIdx, n ) : string.Empty;//sqlite3DbStrNDup(db, zIdx, n);
if ( string.IsNullOrEmpty( zParent ) )
break;
sqlite3Dequote( ref zParent );
if ( zOld.Equals( zParent, StringComparison.OrdinalIgnoreCase ) )
{
string zOut = sqlite3MPrintf( db, "%s%.*s\"%w\"",
zOutput, zIdx - zLeft, zInput.Substring( zLeft ), zNew
);
sqlite3DbFree( db, ref zOutput );
zOutput = zOut;
zIdx += n;// zInput = &z[n];
zLeft = zIdx;
}
sqlite3DbFree( db, ref zParent );
}
}
zResult = sqlite3MPrintf( db, "%s%s", zOutput, zInput.Substring( zLeft ) );
sqlite3_result_text( context, zResult, -1, SQLITE_DYNAMIC );
sqlite3DbFree( db, ref zOutput );
}
#endif
#if !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 NotUsed,
sqlite3_value[] argv
)
{
string zSql = sqlite3_value_text( argv[0] );
string zTableName = sqlite3_value_text( argv[1] );
int token = 0;
Token tname = new Token();
int dist = 3;
int zCsr = 0;
int zLoc = 0;
int len = 1;
string zRet;
sqlite3 db = sqlite3_context_db_handle( context );
UNUSED_PARAMETER( NotUsed );
/* 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 != null )
{
do
{
if ( zCsr == zSql.Length )
{
/* Ran out of input before finding the table name. Return NULL. */
return;
}
/* Store the token that zCsr points to in tname. */
zLoc = zCsr;
tname.z = zSql.Substring( zCsr, len );//(char*)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 = ( zCsr == zSql.Length ) ? 1 : sqlite3GetToken( zSql, zCsr, ref token );
} while ( token == TK_SPACE );
Debug.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\"%w\"%s", zLoc, zSql.Substring( 0, zLoc ),
zTableName, zSql.Substring( zLoc + tname.n ) );
sqlite3_result_text( context, zRet, -1, SQLITE_DYNAMIC );
}
}
#endif // * !SQLITE_OMIT_TRIGGER */
/*
** Register built-in functions used to help implement ALTER TABLE
*/
static FuncDef[] aAlterTableFuncs;
static void sqlite3AlterFunctions()
{
aAlterTableFuncs = new FuncDef[] {
FUNCTION("sqlite_rename_table", 2, 0, 0, renameTableFunc),
#if !SQLITE_OMIT_TRIGGER
FUNCTION("sqlite_rename_trigger", 2, 0, 0, renameTriggerFunc),
#endif
#if !SQLITE_OMIT_FOREIGN_KEY
FUNCTION("sqlite_rename_parent", 3, 0, 0, renameParentFunc),
#endif
};
#if SQLITE_OMIT_WSD
FuncDefHash pHash = GLOBAL(FuncDefHash, sqlite3GlobalFunctions);
FuncDef[] aFunc = GLOBAL(FuncDef, aAlterTableFuncs);
#else
FuncDefHash pHash = sqlite3GlobalFunctions;
FuncDef[] aFunc = aAlterTableFuncs;
#endif
for (int i = 0; i < ArraySize( aAlterTableFuncs ); i++ )
{
sqlite3FuncDefInsert( pHash, aFunc[i] );
}
}
/*
** 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 string whereOrName( sqlite3 db, string zWhere, string zConstant )
{
string zNew;
if ( string.IsNullOrEmpty( zWhere ) )
{
zNew = sqlite3MPrintf( db, "name=%Q", zConstant );
}
else
{
zNew = sqlite3MPrintf( db, "%s OR name=%Q", zWhere, zConstant );
sqlite3DbFree( db, ref zWhere );
}
return zNew;
}
#if !(SQLITE_OMIT_FOREIGN_KEY) && !(SQLITE_OMIT_TRIGGER)
/*
** 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 string whereForeignKeys( Parse pParse, Table pTab )
{
FKey p;
string zWhere = string.Empty;
for ( p = sqlite3FkReferences( pTab ); p != null; p = p.pNextTo )
{
zWhere = whereOrName( pParse.db, zWhere, p.pFrom.zName );
}
return zWhere;
}
#endif
/*
** 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 string whereTempTriggers( Parse pParse, Table pTab )
{
Trigger pTrig;
string zWhere = string.Empty;
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 = sqlite3TriggerList( pParse, pTab ); pTrig != null; pTrig = pTrig.pNext )
{
if ( pTrig.pSchema == pTempSchema )
{
zWhere = whereOrName( db, zWhere, pTrig.zName );
}
}
}
if ( !string.IsNullOrEmpty( zWhere ) )
{
zWhere = sqlite3MPrintf( pParse.db, "type='trigger' AND (%s)", zWhere );
//sqlite3DbFree( pParse.db, ref zWhere );
//zWhere = zNew;
}
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, string zName )
{
Vdbe v;
string zWhere;
int iDb; /* Index of database containing pTab */
#if !SQLITE_OMIT_TRIGGER
Trigger pTrig;
#endif
v = sqlite3GetVdbe( pParse );
if ( NEVER( v == null ) )
return;
Debug.Assert( sqlite3BtreeHoldsAllMutexes( pParse.db ) );
iDb = sqlite3SchemaToIndex( pParse.db, pTab.pSchema );
Debug.Assert( iDb >= 0 );
#if !SQLITE_OMIT_TRIGGER
/* Drop any table triggers from the internal schema. */
for ( pTrig = sqlite3TriggerList( pParse, pTab ); pTrig != null; pTrig = pTrig.pNext )
{
int iTrigDb = sqlite3SchemaToIndex( pParse.db, pTrig.pSchema );
Debug.Assert( iTrigDb == iDb || iTrigDb == 1 );
sqlite3VdbeAddOp4( v, OP_DropTrigger, iTrigDb, 0, 0, pTrig.zName, 0 );
}
#endif
/* 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. */
zWhere = sqlite3MPrintf( pParse.db, "tbl_name=%Q", zName );
if ( zWhere == null )
return;
sqlite3VdbeAddParseSchemaOp( v, iDb, zWhere );
#if !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 ) ).Length > 0 )
{
sqlite3VdbeAddParseSchemaOp( v, 1, zWhere );
}
#endif
}
/*
** Parameter zName is the name of a table that is about to be altered
** (either with ALTER TABLE ... RENAME TO or ALTER TABLE ... ADD COLUMN).
** If the table is a system table, this function leaves an error message
** in pParse->zErr (system tables may not be altered) and returns non-zero.
**
** Or, if zName is not a system table, zero is returned.
*/
static int isSystemTable( Parse pParse, string zName )
{
if ( zName.StartsWith( "sqlite_", System.StringComparison.OrdinalIgnoreCase ) )
{
sqlite3ErrorMsg( pParse, "table %s may not be altered", zName );
return 1;
}
return 0;
}
/*
** Generate code to implement the "ALTER TABLE xxx RENAME TO yyy"
** command.
*/
static 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 */
string zDb; /* Name of database iDb */
Table pTab; /* Table being renamed */
string zName = null; /* NULL-terminated version of pName */
sqlite3 db = pParse.db; /* Database connection */
int nTabName; /* Number of UTF-8 characters in zTabName */
string zTabName; /* Original name of the table */
Vdbe v;
#if !SQLITE_OMIT_TRIGGER
string zWhere = string.Empty; /* Where clause to locate temp triggers */
#endif
VTable pVTab = null; /* Non-zero if this is a v-tab with an xRename() */
int savedDbFlags; /* Saved value of db->flags */
savedDbFlags = db.flags;
//if ( NEVER( db.mallocFailed != 0 ) ) goto exit_rename_table;
Debug.Assert( pSrc.nSrc == 1 );
Debug.Assert( sqlite3BtreeHoldsAllMutexes( pParse.db ) );
pTab = sqlite3LocateTable( pParse, 0, pSrc.a[0].zName, pSrc.a[0].zDatabase );
if ( pTab == null )
goto exit_rename_table;
iDb = sqlite3SchemaToIndex( pParse.db, pTab.pSchema );
zDb = db.aDb[iDb].zName;
db.flags |= SQLITE_PreferBuiltin;
/* Get a NULL terminated version of the new table name. */
zName = sqlite3NameFromToken( db, pName );
if ( zName == null )
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 ) != null || sqlite3FindIndex( db, zName, zDb ) != null )
{
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 ( SQLITE_OK!=isSystemTable(pParse, pTab.zName) )
{
goto exit_rename_table;
}
if ( SQLITE_OK != sqlite3CheckObjectName( pParse, zName ) )
{
goto exit_rename_table;
}
#if !SQLITE_OMIT_VIEW
if ( pTab.pSelect != null )
{
sqlite3ErrorMsg( pParse, "view %s may not be altered", pTab.zName );
goto exit_rename_table;
}
#endif
#if !SQLITE_OMIT_AUTHORIZATION
/* Invoke the authorization callback. */
if( sqlite3AuthCheck(pParse, SQLITE_ALTER_TABLE, zDb, pTab.zName, 0) ){
goto exit_rename_table;
}
#endif
if ( sqlite3ViewGetColumnNames( pParse, pTab ) != 0 )
{
goto exit_rename_table;
}
#if !SQLITE_OMIT_VIRTUALTABLE
if ( IsVirtual( pTab ) )
{
pVTab = sqlite3GetVTable( db, pTab );
if ( pVTab.pVtab.pModule.xRename == null )
{
pVTab = null;
}
}
#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 == null )
{
goto exit_rename_table;
}
sqlite3BeginWriteOperation( pParse, pVTab != null ? 1 : 0, iDb );
sqlite3ChangeCookie( pParse, 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.
*/
#if !SQLITE_OMIT_VIRTUALTABLE
if ( pVTab !=null)
{
int i = ++pParse.nMem;
sqlite3VdbeAddOp4( v, OP_String8, 0, i, 0, zName, 0 );
sqlite3VdbeAddOp4( v, OP_VRename, i, 0, 0, pVTab, P4_VTAB );
sqlite3MayAbort(pParse);
}
#endif
/* figure out how many UTF-8 characters are in zName */
zTabName = pTab.zName;
nTabName = sqlite3Utf8CharLen( zTabName, -1 );
#if !(SQLITE_OMIT_FOREIGN_KEY) && !(SQLITE_OMIT_TRIGGER)
if ( ( db.flags & SQLITE_ForeignKeys ) != 0 )
{
/* 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 ) ) != null )
{
sqlite3NestedParse( pParse,
"UPDATE \"%w\".%s SET " +
"sql = sqlite_rename_parent(sql, %Q, %Q) " +
"WHERE %s;", zDb, SCHEMA_TABLE( iDb ), zTabName, zName, zWhere );
sqlite3DbFree( db, ref zWhere );
}
}
#endif
/* Modify the sqlite_master table to use the new table name. */
sqlite3NestedParse( pParse,
"UPDATE %Q.%s SET " +
#if 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,
#if !SQLITE_OMIT_TRIGGER
zName,
#endif
zName, nTabName, zTabName
);
#if !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 ) != null )
{
sqlite3NestedParse( pParse,
"UPDATE \"%w\".sqlite_sequence set name = %Q WHERE name = %Q",
zDb, zName, pTab.zName
);
}
#endif
#if !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 ) ).Length > 0 )
{
sqlite3NestedParse( pParse,
"UPDATE sqlite_temp_master SET " +
"sql = sqlite_rename_trigger(sql, %Q), " +
"tbl_name = %Q " +
"WHERE %s;", zName, zName, zWhere );
sqlite3DbFree( db, ref zWhere );
}
#endif
#if !(SQLITE_OMIT_FOREIGN_KEY) && !(SQLITE_OMIT_TRIGGER)
if ( ( db.flags & SQLITE_ForeignKeys ) != 0 )
{
FKey p;
for ( p = sqlite3FkReferences( pTab ); p != null; 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 );
exit_rename_table:
sqlite3SrcListDelete( db, ref pSrc );
sqlite3DbFree( db, ref zName );
db.flags = savedDbFlags;
}
/*
** Generate code to make sure the file format number is at least minFormat.
** The generated code will increase the file format number if necessary.
*/
static void sqlite3MinimumFileFormat( Parse pParse, int iDb, int minFormat )
{
Vdbe v;
v = sqlite3GetVdbe( pParse );
/* The VDBE should have been allocated before this routine is called.
** If that allocation failed, we would have quit before reaching this
** point */
if ( ALWAYS( v ) )
{
int r1 = sqlite3GetTempReg( pParse );
int r2 = sqlite3GetTempReg( pParse );
int j1;
sqlite3VdbeAddOp3( v, OP_ReadCookie, iDb, r1, BTREE_FILE_FORMAT );
sqlite3VdbeUsesBtree( v, iDb );
sqlite3VdbeAddOp2( v, OP_Integer, minFormat, r2 );
j1 = sqlite3VdbeAddOp3( v, OP_Ge, r2, 0, r1 );
sqlite3VdbeAddOp3( v, OP_SetCookie, iDb, BTREE_FILE_FORMAT, r2 );
sqlite3VdbeJumpHere( v, j1 );
sqlite3ReleaseTempReg( pParse, r1 );
sqlite3ReleaseTempReg( pParse, r2 );
}
}
/*
** 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.
*/
static void sqlite3AlterFinishAddColumn( Parse pParse, Token pColDef )
{
Table pNew; /* Copy of pParse.pNewTable */
Table pTab; /* Table being altered */
int iDb; /* Database number */
string zDb; /* Database name */
string zTab; /* Table name */
string zCol; /* Null-terminated column definition */
Column pCol; /* The new column */
Expr pDflt; /* Default value for the new column */
sqlite3 db; /* The database connection; */
db = pParse.db;
if ( pParse.nErr != 0 /*|| db.mallocFailed != 0 */ )
return;
pNew = pParse.pNewTable;
Debug.Assert( pNew != null );
Debug.Assert( sqlite3BtreeHoldsAllMutexes( db ) );
iDb = sqlite3SchemaToIndex( db, pNew.pSchema );
zDb = db.aDb[iDb].zName;
zTab = pNew.zName.Substring( 16 );// zTab = &pNew->zName[16]; /* Skip the "sqlite_altertab_" prefix on the name */
pCol = pNew.aCol[pNew.nCol - 1];
pDflt = pCol.pDflt;
pTab = sqlite3FindTable( db, zTab, zDb );
Debug.Assert( pTab != null );
#if !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 != null && pDflt.op == TK_NULL )
{
pDflt = null;
}
/* 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 != 0 )
{
sqlite3ErrorMsg( pParse, "Cannot add a PRIMARY KEY column" );
return;
}
if ( pNew.pIndex != null )
{
sqlite3ErrorMsg( pParse, "Cannot add a UNIQUE column" );
return;
}
if ( ( db.flags & SQLITE_ForeignKeys ) != 0 && pNew.pFKey != null && pDflt != null )
{
sqlite3ErrorMsg( pParse,
"Cannot add a REFERENCES column with non-NULL default value" );
return;
}
if ( pCol.notNull != 0 && pDflt == null )
{
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 != null )
{
sqlite3_value pVal = null;
if ( sqlite3ValueFromExpr( db, pDflt, SQLITE_UTF8, SQLITE_AFF_NONE, ref pVal ) != 0 )
{
// db.mallocFailed = 1;
return;
}
if ( pVal == null )
{
sqlite3ErrorMsg( pParse, "Cannot add a column with non-constant default" );
return;
}
sqlite3ValueFree( ref pVal );
}
/* Modify the CREATE TABLE statement. */
zCol = pColDef.z.Substring( 0, pColDef.n ).Replace( ";", " " ).Trim();//sqlite3DbStrNDup(db, (char*)pColDef.z, pColDef.n);
if ( zCol != null )
{
// char zEnd = zCol[pColDef.n-1];
int savedDbFlags = db.flags;
// while( zEnd>zCol && (*zEnd==';' || sqlite3Isspace(*zEnd)) ){
// zEnd-- = '\0';
// }
db.flags |= SQLITE_PreferBuiltin;
sqlite3NestedParse( pParse,
"UPDATE \"%w\".%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
);
sqlite3DbFree( db, ref zCol );
db.flags = savedDbFlags;
}
/* 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 != null ? 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.
*/
static 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. */
Debug.Assert( pParse.pNewTable == null );
Debug.Assert( sqlite3BtreeHoldsAllMutexes( db ) );
// if ( db.mallocFailed != 0 ) goto exit_begin_add_column;
pTab = sqlite3LocateTable( pParse, 0, pSrc.a[0].zName, pSrc.a[0].zDatabase );
if ( pTab == null )
goto exit_begin_add_column;
if ( IsVirtual( pTab ) )
{
sqlite3ErrorMsg( pParse, "virtual tables may not be altered" );
goto exit_begin_add_column;
}
/* Make sure this is not an attempt to ALTER a view. */
if ( pTab.pSelect != null )
{
sqlite3ErrorMsg( pParse, "Cannot add a column to a view" );
goto exit_begin_add_column;
}
if ( SQLITE_OK != isSystemTable( pParse, pTab.zName ) )
{
goto exit_begin_add_column;
}
Debug.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. But modify
** the name by adding an "sqlite_altertab_" prefix. By adding this
** prefix, we insure that the name will not collide with an existing
** table because user table are not allowed to have the "sqlite_"
** prefix on their name.
*/
pNew = new Table();// (Table*)sqlite3DbMallocZero( db, sizeof(Table))
if ( pNew == null )
goto exit_begin_add_column;
pParse.pNewTable = pNew;
pNew.nRef = 1;
pNew.nCol = pTab.nCol;
Debug.Assert( pNew.nCol > 0 );
nAlloc = ( ( ( pNew.nCol - 1 ) / 8 ) * 8 ) + 8;
Debug.Assert( nAlloc >= pNew.nCol && nAlloc % 8 == 0 && nAlloc - pNew.nCol < 8 );
pNew.aCol = new Column[nAlloc];// (Column*)sqlite3DbMallocZero( db, sizeof(Column) * nAlloc );
pNew.zName = sqlite3MPrintf( db, "sqlite_altertab_%s", pTab.zName );
if ( pNew.aCol == null || pNew.zName == null )
{
// 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 = pTab.aCol[i].Copy();
// sqlite3DbStrDup( db, pCol.zName );
pCol.zColl = null;
pCol.zType = null;
pCol.pDflt = null;
pCol.zDflt = null;
pNew.aCol[i] = pCol;
}
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 == null )
goto exit_begin_add_column;
sqlite3ChangeCookie( pParse, iDb );
exit_begin_add_column:
sqlite3SrcListDelete( db, ref pSrc );
return;
}
#endif // * SQLITE_ALTER_TABLE */
}
}
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