blob: 1dcb407edd0c49593dd285ca0c3d9883bda5c596 [file] [log] [blame]
/*
** 2003 April 6
**
** 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 code used to implement the ATTACH and DETACH commands.
*/
#include "sqliteInt.h"
#ifndef SQLITE_OMIT_ATTACH
/*
** Resolve an expression that was part of an ATTACH or DETACH statement. This
** is slightly different from resolving a normal SQL expression, because simple
** identifiers are treated as strings, not possible column names or aliases.
**
** i.e. if the parser sees:
**
** ATTACH DATABASE abc AS def
**
** it treats the two expressions as literal strings 'abc' and 'def' instead of
** looking for columns of the same name.
**
** This only applies to the root node of pExpr, so the statement:
**
** ATTACH DATABASE abc||def AS 'db2'
**
** will fail because neither abc or def can be resolved.
*/
static int resolveAttachExpr(NameContext *pName, Expr *pExpr)
{
int rc = SQLITE_OK;
if( pExpr ){
if( pExpr->op!=TK_ID ){
rc = sqlite3ResolveExprNames(pName, pExpr);
}else{
pExpr->op = TK_STRING;
}
}
return rc;
}
/*
** An SQL user-function registered to do the work of an ATTACH statement. The
** three arguments to the function come directly from an attach statement:
**
** ATTACH DATABASE x AS y KEY z
**
** SELECT sqlite_attach(x, y, z)
**
** If the optional "KEY z" syntax is omitted, an SQL NULL is passed as the
** third argument.
**
** If the db->init.reopenMemdb flags is set, then instead of attaching a
** new database, close the database on db->init.iDb and reopen it as an
** empty MemDB.
*/
static void attachFunc(
sqlite3_context *context,
int NotUsed,
sqlite3_value **argv
){
int i;
int rc = 0;
sqlite3 *db = sqlite3_context_db_handle(context);
const char *zName;
const char *zFile;
char *zPath = 0;
char *zErr = 0;
unsigned int flags;
Db *aNew; /* New array of Db pointers */
Db *pNew; /* Db object for the newly attached database */
char *zErrDyn = 0;
sqlite3_vfs *pVfs;
UNUSED_PARAMETER(NotUsed);
zFile = (const char *)sqlite3_value_text(argv[0]);
zName = (const char *)sqlite3_value_text(argv[1]);
if( zFile==0 ) zFile = "";
if( zName==0 ) zName = "";
#ifdef SQLITE_ENABLE_DESERIALIZE
# define REOPEN_AS_MEMDB(db) (db->init.reopenMemdb)
#else
# define REOPEN_AS_MEMDB(db) (0)
#endif
if( REOPEN_AS_MEMDB(db) ){
/* This is not a real ATTACH. Instead, this routine is being called
** from sqlite3_deserialize() to close database db->init.iDb and
** reopen it as a MemDB */
pVfs = sqlite3_vfs_find("memdb");
if( pVfs==0 ) return;
pNew = &db->aDb[db->init.iDb];
if( pNew->pBt ) sqlite3BtreeClose(pNew->pBt);
pNew->pBt = 0;
pNew->pSchema = 0;
rc = sqlite3BtreeOpen(pVfs, "x\0", db, &pNew->pBt, 0, SQLITE_OPEN_MAIN_DB);
}else{
/* This is a real ATTACH
**
** Check for the following errors:
**
** * Too many attached databases,
** * Transaction currently open
** * Specified database name already being used.
*/
if( db->nDb>=db->aLimit[SQLITE_LIMIT_ATTACHED]+2 ){
zErrDyn = sqlite3MPrintf(db, "too many attached databases - max %d",
db->aLimit[SQLITE_LIMIT_ATTACHED]
);
goto attach_error;
}
for(i=0; i<db->nDb; i++){
char *z = db->aDb[i].zDbSName;
assert( z && zName );
if( sqlite3StrICmp(z, zName)==0 ){
zErrDyn = sqlite3MPrintf(db, "database %s is already in use", zName);
goto attach_error;
}
}
/* Allocate the new entry in the db->aDb[] array and initialize the schema
** hash tables.
*/
if( db->aDb==db->aDbStatic ){
aNew = sqlite3DbMallocRawNN(db, sizeof(db->aDb[0])*3 );
if( aNew==0 ) return;
memcpy(aNew, db->aDb, sizeof(db->aDb[0])*2);
}else{
aNew = sqlite3DbRealloc(db, db->aDb, sizeof(db->aDb[0])*(db->nDb+1) );
if( aNew==0 ) return;
}
db->aDb = aNew;
pNew = &db->aDb[db->nDb];
memset(pNew, 0, sizeof(*pNew));
/* Open the database file. If the btree is successfully opened, use
** it to obtain the database schema. At this point the schema may
** or may not be initialized.
*/
flags = db->openFlags;
rc = sqlite3ParseUri(db->pVfs->zName, zFile, &flags, &pVfs, &zPath, &zErr);
if( rc!=SQLITE_OK ){
if( rc==SQLITE_NOMEM ) sqlite3OomFault(db);
sqlite3_result_error(context, zErr, -1);
sqlite3_free(zErr);
return;
}
assert( pVfs );
flags |= SQLITE_OPEN_MAIN_DB;
rc = sqlite3BtreeOpen(pVfs, zPath, db, &pNew->pBt, 0, flags);
db->nDb++;
pNew->zDbSName = sqlite3DbStrDup(db, zName);
}
db->noSharedCache = 0;
if( rc==SQLITE_CONSTRAINT ){
rc = SQLITE_ERROR;
zErrDyn = sqlite3MPrintf(db, "database is already attached");
}else if( rc==SQLITE_OK ){
Pager *pPager;
pNew->pSchema = sqlite3SchemaGet(db, pNew->pBt);
if( !pNew->pSchema ){
rc = SQLITE_NOMEM_BKPT;
}else if( pNew->pSchema->file_format && pNew->pSchema->enc!=ENC(db) ){
zErrDyn = sqlite3MPrintf(db,
"attached databases must use the same text encoding as main database");
rc = SQLITE_ERROR;
}
sqlite3BtreeEnter(pNew->pBt);
pPager = sqlite3BtreePager(pNew->pBt);
sqlite3PagerLockingMode(pPager, db->dfltLockMode);
sqlite3BtreeSecureDelete(pNew->pBt,
sqlite3BtreeSecureDelete(db->aDb[0].pBt,-1) );
#ifndef SQLITE_OMIT_PAGER_PRAGMAS
sqlite3BtreeSetPagerFlags(pNew->pBt,
PAGER_SYNCHRONOUS_FULL | (db->flags & PAGER_FLAGS_MASK));
#endif
sqlite3BtreeLeave(pNew->pBt);
}
pNew->safety_level = SQLITE_DEFAULT_SYNCHRONOUS+1;
if( rc==SQLITE_OK && pNew->zDbSName==0 ){
rc = SQLITE_NOMEM_BKPT;
}
#ifdef SQLITE_HAS_CODEC
if( rc==SQLITE_OK ){
extern int sqlite3CodecAttach(sqlite3*, int, const void*, int);
extern void sqlite3CodecGetKey(sqlite3*, int, void**, int*);
int nKey;
char *zKey;
int t = sqlite3_value_type(argv[2]);
switch( t ){
case SQLITE_INTEGER:
case SQLITE_FLOAT:
zErrDyn = sqlite3DbStrDup(db, "Invalid key value");
rc = SQLITE_ERROR;
break;
case SQLITE_TEXT:
case SQLITE_BLOB:
nKey = sqlite3_value_bytes(argv[2]);
zKey = (char *)sqlite3_value_blob(argv[2]);
rc = sqlite3CodecAttach(db, db->nDb-1, zKey, nKey);
break;
case SQLITE_NULL:
/* No key specified. Use the key from URI filename, or if none,
** use the key from the main database. */
if( sqlite3CodecQueryParameters(db, zName, zPath)==0 ){
sqlite3CodecGetKey(db, 0, (void**)&zKey, &nKey);
if( nKey || sqlite3BtreeGetOptimalReserve(db->aDb[0].pBt)>0 ){
rc = sqlite3CodecAttach(db, db->nDb-1, zKey, nKey);
}
}
break;
}
}
#endif
sqlite3_free( zPath );
/* If the file was opened successfully, read the schema for the new database.
** If this fails, or if opening the file failed, then close the file and
** remove the entry from the db->aDb[] array. i.e. put everything back the
** way we found it.
*/
if( rc==SQLITE_OK ){
sqlite3BtreeEnterAll(db);
db->init.iDb = 0;
db->mDbFlags &= ~(DBFLAG_SchemaKnownOk);
if( !REOPEN_AS_MEMDB(db) ){
rc = sqlite3Init(db, &zErrDyn);
}
sqlite3BtreeLeaveAll(db);
assert( zErrDyn==0 || rc!=SQLITE_OK );
}
#ifdef SQLITE_USER_AUTHENTICATION
if( rc==SQLITE_OK && !REOPEN_AS_MEMDB(db) ){
u8 newAuth = 0;
rc = sqlite3UserAuthCheckLogin(db, zName, &newAuth);
if( newAuth<db->auth.authLevel ){
rc = SQLITE_AUTH_USER;
}
}
#endif
if( rc ){
if( !REOPEN_AS_MEMDB(db) ){
int iDb = db->nDb - 1;
assert( iDb>=2 );
if( db->aDb[iDb].pBt ){
sqlite3BtreeClose(db->aDb[iDb].pBt);
db->aDb[iDb].pBt = 0;
db->aDb[iDb].pSchema = 0;
}
sqlite3ResetAllSchemasOfConnection(db);
db->nDb = iDb;
if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ){
sqlite3OomFault(db);
sqlite3DbFree(db, zErrDyn);
zErrDyn = sqlite3MPrintf(db, "out of memory");
}else if( zErrDyn==0 ){
zErrDyn = sqlite3MPrintf(db, "unable to open database: %s", zFile);
}
}
goto attach_error;
}
return;
attach_error:
/* Return an error if we get here */
if( zErrDyn ){
sqlite3_result_error(context, zErrDyn, -1);
sqlite3DbFree(db, zErrDyn);
}
if( rc ) sqlite3_result_error_code(context, rc);
}
/*
** An SQL user-function registered to do the work of an DETACH statement. The
** three arguments to the function come directly from a detach statement:
**
** DETACH DATABASE x
**
** SELECT sqlite_detach(x)
*/
static void detachFunc(
sqlite3_context *context,
int NotUsed,
sqlite3_value **argv
){
const char *zName = (const char *)sqlite3_value_text(argv[0]);
sqlite3 *db = sqlite3_context_db_handle(context);
int i;
Db *pDb = 0;
HashElem *pEntry;
char zErr[128];
UNUSED_PARAMETER(NotUsed);
if( zName==0 ) zName = "";
for(i=0; i<db->nDb; i++){
pDb = &db->aDb[i];
if( pDb->pBt==0 ) continue;
if( sqlite3StrICmp(pDb->zDbSName, zName)==0 ) break;
}
if( i>=db->nDb ){
sqlite3_snprintf(sizeof(zErr),zErr, "no such database: %s", zName);
goto detach_error;
}
if( i<2 ){
sqlite3_snprintf(sizeof(zErr),zErr, "cannot detach database %s", zName);
goto detach_error;
}
if( sqlite3BtreeIsInReadTrans(pDb->pBt) || sqlite3BtreeIsInBackup(pDb->pBt) ){
sqlite3_snprintf(sizeof(zErr),zErr, "database %s is locked", zName);
goto detach_error;
}
/* If any TEMP triggers reference the schema being detached, move those
** triggers to reference the TEMP schema itself. */
assert( db->aDb[1].pSchema );
pEntry = sqliteHashFirst(&db->aDb[1].pSchema->trigHash);
while( pEntry ){
Trigger *pTrig = (Trigger*)sqliteHashData(pEntry);
if( pTrig->pTabSchema==pDb->pSchema ){
pTrig->pTabSchema = pTrig->pSchema;
}
pEntry = sqliteHashNext(pEntry);
}
sqlite3BtreeClose(pDb->pBt);
pDb->pBt = 0;
pDb->pSchema = 0;
sqlite3CollapseDatabaseArray(db);
return;
detach_error:
sqlite3_result_error(context, zErr, -1);
}
/*
** This procedure generates VDBE code for a single invocation of either the
** sqlite_detach() or sqlite_attach() SQL user functions.
*/
static void codeAttach(
Parse *pParse, /* The parser context */
int type, /* Either SQLITE_ATTACH or SQLITE_DETACH */
FuncDef const *pFunc,/* FuncDef wrapper for detachFunc() or attachFunc() */
Expr *pAuthArg, /* Expression to pass to authorization callback */
Expr *pFilename, /* Name of database file */
Expr *pDbname, /* Name of the database to use internally */
Expr *pKey /* Database key for encryption extension */
){
int rc;
NameContext sName;
Vdbe *v;
sqlite3* db = pParse->db;
int regArgs;
if( pParse->nErr ) goto attach_end;
memset(&sName, 0, sizeof(NameContext));
sName.pParse = pParse;
if(
SQLITE_OK!=(rc = resolveAttachExpr(&sName, pFilename)) ||
SQLITE_OK!=(rc = resolveAttachExpr(&sName, pDbname)) ||
SQLITE_OK!=(rc = resolveAttachExpr(&sName, pKey))
){
goto attach_end;
}
#ifndef SQLITE_OMIT_AUTHORIZATION
if( pAuthArg ){
char *zAuthArg;
if( pAuthArg->op==TK_STRING ){
zAuthArg = pAuthArg->u.zToken;
}else{
zAuthArg = 0;
}
rc = sqlite3AuthCheck(pParse, type, zAuthArg, 0, 0);
if(rc!=SQLITE_OK ){
goto attach_end;
}
}
#endif /* SQLITE_OMIT_AUTHORIZATION */
v = sqlite3GetVdbe(pParse);
regArgs = sqlite3GetTempRange(pParse, 4);
sqlite3ExprCode(pParse, pFilename, regArgs);
sqlite3ExprCode(pParse, pDbname, regArgs+1);
sqlite3ExprCode(pParse, pKey, regArgs+2);
assert( v || db->mallocFailed );
if( v ){
sqlite3VdbeAddOp4(v, OP_Function0, 0, regArgs+3-pFunc->nArg, regArgs+3,
(char *)pFunc, P4_FUNCDEF);
assert( pFunc->nArg==-1 || (pFunc->nArg&0xff)==pFunc->nArg );
sqlite3VdbeChangeP5(v, (u8)(pFunc->nArg));
/* Code an OP_Expire. For an ATTACH statement, set P1 to true (expire this
** statement only). For DETACH, set it to false (expire all existing
** statements).
*/
sqlite3VdbeAddOp1(v, OP_Expire, (type==SQLITE_ATTACH));
}
attach_end:
sqlite3ExprDelete(db, pFilename);
sqlite3ExprDelete(db, pDbname);
sqlite3ExprDelete(db, pKey);
}
/*
** Called by the parser to compile a DETACH statement.
**
** DETACH pDbname
*/
void sqlite3Detach(Parse *pParse, Expr *pDbname){
static const FuncDef detach_func = {
1, /* nArg */
SQLITE_UTF8, /* funcFlags */
0, /* pUserData */
0, /* pNext */
detachFunc, /* xSFunc */
0, /* xFinalize */
0, 0, /* xValue, xInverse */
"sqlite_detach", /* zName */
{0}
};
codeAttach(pParse, SQLITE_DETACH, &detach_func, pDbname, 0, 0, pDbname);
}
/*
** Called by the parser to compile an ATTACH statement.
**
** ATTACH p AS pDbname KEY pKey
*/
void sqlite3Attach(Parse *pParse, Expr *p, Expr *pDbname, Expr *pKey){
static const FuncDef attach_func = {
3, /* nArg */
SQLITE_UTF8, /* funcFlags */
0, /* pUserData */
0, /* pNext */
attachFunc, /* xSFunc */
0, /* xFinalize */
0, 0, /* xValue, xInverse */
"sqlite_attach", /* zName */
{0}
};
codeAttach(pParse, SQLITE_ATTACH, &attach_func, p, p, pDbname, pKey);
}
#endif /* SQLITE_OMIT_ATTACH */
/*
** Initialize a DbFixer structure. This routine must be called prior
** to passing the structure to one of the sqliteFixAAAA() routines below.
*/
void sqlite3FixInit(
DbFixer *pFix, /* The fixer to be initialized */
Parse *pParse, /* Error messages will be written here */
int iDb, /* This is the database that must be used */
const char *zType, /* "view", "trigger", or "index" */
const Token *pName /* Name of the view, trigger, or index */
){
sqlite3 *db;
db = pParse->db;
assert( db->nDb>iDb );
pFix->pParse = pParse;
pFix->zDb = db->aDb[iDb].zDbSName;
pFix->pSchema = db->aDb[iDb].pSchema;
pFix->zType = zType;
pFix->pName = pName;
pFix->bVarOnly = (iDb==1);
}
/*
** The following set of routines walk through the parse tree and assign
** a specific database to all table references where the database name
** was left unspecified in the original SQL statement. The pFix structure
** must have been initialized by a prior call to sqlite3FixInit().
**
** These routines are used to make sure that an index, trigger, or
** view in one database does not refer to objects in a different database.
** (Exception: indices, triggers, and views in the TEMP database are
** allowed to refer to anything.) If a reference is explicitly made
** to an object in a different database, an error message is added to
** pParse->zErrMsg and these routines return non-zero. If everything
** checks out, these routines return 0.
*/
int sqlite3FixSrcList(
DbFixer *pFix, /* Context of the fixation */
SrcList *pList /* The Source list to check and modify */
){
int i;
const char *zDb;
struct SrcList_item *pItem;
if( NEVER(pList==0) ) return 0;
zDb = pFix->zDb;
for(i=0, pItem=pList->a; i<pList->nSrc; i++, pItem++){
if( pFix->bVarOnly==0 ){
if( pItem->zDatabase && sqlite3StrICmp(pItem->zDatabase, zDb) ){
sqlite3ErrorMsg(pFix->pParse,
"%s %T cannot reference objects in database %s",
pFix->zType, pFix->pName, pItem->zDatabase);
return 1;
}
sqlite3DbFree(pFix->pParse->db, pItem->zDatabase);
pItem->zDatabase = 0;
pItem->pSchema = pFix->pSchema;
}
#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER)
if( sqlite3FixSelect(pFix, pItem->pSelect) ) return 1;
if( sqlite3FixExpr(pFix, pItem->pOn) ) return 1;
#endif
if( pItem->fg.isTabFunc && sqlite3FixExprList(pFix, pItem->u1.pFuncArg) ){
return 1;
}
}
return 0;
}
#if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER)
int sqlite3FixSelect(
DbFixer *pFix, /* Context of the fixation */
Select *pSelect /* The SELECT statement to be fixed to one database */
){
while( pSelect ){
if( sqlite3FixExprList(pFix, pSelect->pEList) ){
return 1;
}
if( sqlite3FixSrcList(pFix, pSelect->pSrc) ){
return 1;
}
if( sqlite3FixExpr(pFix, pSelect->pWhere) ){
return 1;
}
if( sqlite3FixExprList(pFix, pSelect->pGroupBy) ){
return 1;
}
if( sqlite3FixExpr(pFix, pSelect->pHaving) ){
return 1;
}
if( sqlite3FixExprList(pFix, pSelect->pOrderBy) ){
return 1;
}
if( sqlite3FixExpr(pFix, pSelect->pLimit) ){
return 1;
}
if( pSelect->pWith ){
int i;
for(i=0; i<pSelect->pWith->nCte; i++){
if( sqlite3FixSelect(pFix, pSelect->pWith->a[i].pSelect) ){
return 1;
}
}
}
pSelect = pSelect->pPrior;
}
return 0;
}
int sqlite3FixExpr(
DbFixer *pFix, /* Context of the fixation */
Expr *pExpr /* The expression to be fixed to one database */
){
while( pExpr ){
ExprSetProperty(pExpr, EP_Indirect);
if( pExpr->op==TK_VARIABLE ){
if( pFix->pParse->db->init.busy ){
pExpr->op = TK_NULL;
}else{
sqlite3ErrorMsg(pFix->pParse, "%s cannot use variables", pFix->zType);
return 1;
}
}
if( ExprHasProperty(pExpr, EP_TokenOnly|EP_Leaf) ) break;
if( ExprHasProperty(pExpr, EP_xIsSelect) ){
if( sqlite3FixSelect(pFix, pExpr->x.pSelect) ) return 1;
}else{
if( sqlite3FixExprList(pFix, pExpr->x.pList) ) return 1;
}
if( sqlite3FixExpr(pFix, pExpr->pRight) ){
return 1;
}
pExpr = pExpr->pLeft;
}
return 0;
}
int sqlite3FixExprList(
DbFixer *pFix, /* Context of the fixation */
ExprList *pList /* The expression to be fixed to one database */
){
int i;
struct ExprList_item *pItem;
if( pList==0 ) return 0;
for(i=0, pItem=pList->a; i<pList->nExpr; i++, pItem++){
if( sqlite3FixExpr(pFix, pItem->pExpr) ){
return 1;
}
}
return 0;
}
#endif
#ifndef SQLITE_OMIT_TRIGGER
int sqlite3FixTriggerStep(
DbFixer *pFix, /* Context of the fixation */
TriggerStep *pStep /* The trigger step be fixed to one database */
){
while( pStep ){
if( sqlite3FixSelect(pFix, pStep->pSelect) ){
return 1;
}
if( sqlite3FixExpr(pFix, pStep->pWhere) ){
return 1;
}
if( sqlite3FixExprList(pFix, pStep->pExprList) ){
return 1;
}
#ifndef SQLITE_OMIT_UPSERT
if( pStep->pUpsert ){
Upsert *pUp = pStep->pUpsert;
if( sqlite3FixExprList(pFix, pUp->pUpsertTarget)
|| sqlite3FixExpr(pFix, pUp->pUpsertTargetWhere)
|| sqlite3FixExprList(pFix, pUp->pUpsertSet)
|| sqlite3FixExpr(pFix, pUp->pUpsertWhere)
){
return 1;
}
}
#endif
pStep = pStep->pNext;
}
return 0;
}
#endif