4 ** The author disclaims copyright to this source code. In place of
5 ** a legal notice, here is a blessing:
7 ** May you do good and not evil.
8 ** May you find forgiveness for yourself and forgive others.
9 ** May you share freely, never taking more than you give.
11 *************************************************************************
12 ** This file contains code used to implement the ATTACH and DETACH commands.
14 #include "sqliteInt.h"
16 #ifndef SQLITE_OMIT_ATTACH
18 ** Resolve an expression that was part of an ATTACH or DETACH statement. This
19 ** is slightly different from resolving a normal SQL expression, because simple
20 ** identifiers are treated as strings, not possible column names or aliases.
22 ** i.e. if the parser sees:
24 ** ATTACH DATABASE abc AS def
26 ** it treats the two expressions as literal strings 'abc' and 'def' instead of
27 ** looking for columns of the same name.
29 ** This only applies to the root node of pExpr, so the statement:
31 ** ATTACH DATABASE abc||def AS 'db2'
33 ** will fail because neither abc or def can be resolved.
35 static int resolveAttachExpr(NameContext
*pName
, Expr
*pExpr
)
39 if( pExpr
->op
!=TK_ID
){
40 rc
= sqlite3ResolveExprNames(pName
, pExpr
);
42 pExpr
->op
= TK_STRING
;
49 ** An SQL user-function registered to do the work of an ATTACH statement. The
50 ** three arguments to the function come directly from an attach statement:
52 ** ATTACH DATABASE x AS y KEY z
54 ** SELECT sqlite_attach(x, y, z)
56 ** If the optional "KEY z" syntax is omitted, an SQL NULL is passed as the
59 ** If the db->init.reopenMemdb flags is set, then instead of attaching a
60 ** new database, close the database on db->init.iDb and reopen it as an
63 static void attachFunc(
64 sqlite3_context
*context
,
70 sqlite3
*db
= sqlite3_context_db_handle(context
);
76 Db
*aNew
; /* New array of Db pointers */
77 Db
*pNew
; /* Db object for the newly attached database */
81 UNUSED_PARAMETER(NotUsed
);
82 zFile
= (const char *)sqlite3_value_text(argv
[0]);
83 zName
= (const char *)sqlite3_value_text(argv
[1]);
84 if( zFile
==0 ) zFile
= "";
85 if( zName
==0 ) zName
= "";
87 #ifdef SQLITE_ENABLE_DESERIALIZE
88 # define REOPEN_AS_MEMDB(db) (db->init.reopenMemdb)
90 # define REOPEN_AS_MEMDB(db) (0)
93 if( REOPEN_AS_MEMDB(db
) ){
94 /* This is not a real ATTACH. Instead, this routine is being called
95 ** from sqlite3_deserialize() to close database db->init.iDb and
96 ** reopen it as a MemDB */
97 pVfs
= sqlite3_vfs_find("memdb");
99 pNew
= &db
->aDb
[db
->init
.iDb
];
100 if( pNew
->pBt
) sqlite3BtreeClose(pNew
->pBt
);
103 rc
= sqlite3BtreeOpen(pVfs
, "x", db
, &pNew
->pBt
, 0, SQLITE_OPEN_MAIN_DB
);
105 /* This is a real ATTACH
107 ** Check for the following errors:
109 ** * Too many attached databases,
110 ** * Transaction currently open
111 ** * Specified database name already being used.
113 if( db
->nDb
>=db
->aLimit
[SQLITE_LIMIT_ATTACHED
]+2 ){
114 zErrDyn
= sqlite3MPrintf(db
, "too many attached databases - max %d",
115 db
->aLimit
[SQLITE_LIMIT_ATTACHED
]
119 for(i
=0; i
<db
->nDb
; i
++){
120 char *z
= db
->aDb
[i
].zDbSName
;
121 assert( z
&& zName
);
122 if( sqlite3StrICmp(z
, zName
)==0 ){
123 zErrDyn
= sqlite3MPrintf(db
, "database %s is already in use", zName
);
128 /* Allocate the new entry in the db->aDb[] array and initialize the schema
131 if( db
->aDb
==db
->aDbStatic
){
132 aNew
= sqlite3DbMallocRawNN(db
, sizeof(db
->aDb
[0])*3 );
133 if( aNew
==0 ) return;
134 memcpy(aNew
, db
->aDb
, sizeof(db
->aDb
[0])*2);
136 aNew
= sqlite3DbRealloc(db
, db
->aDb
, sizeof(db
->aDb
[0])*(db
->nDb
+1) );
137 if( aNew
==0 ) return;
140 pNew
= &db
->aDb
[db
->nDb
];
141 memset(pNew
, 0, sizeof(*pNew
));
143 /* Open the database file. If the btree is successfully opened, use
144 ** it to obtain the database schema. At this point the schema may
145 ** or may not be initialized.
147 flags
= db
->openFlags
;
148 rc
= sqlite3ParseUri(db
->pVfs
->zName
, zFile
, &flags
, &pVfs
, &zPath
, &zErr
);
150 if( rc
==SQLITE_NOMEM
) sqlite3OomFault(db
);
151 sqlite3_result_error(context
, zErr
, -1);
156 flags
|= SQLITE_OPEN_MAIN_DB
;
157 rc
= sqlite3BtreeOpen(pVfs
, zPath
, db
, &pNew
->pBt
, 0, flags
);
158 sqlite3_free( zPath
);
161 db
->skipBtreeMutex
= 0;
162 if( rc
==SQLITE_CONSTRAINT
){
164 zErrDyn
= sqlite3MPrintf(db
, "database is already attached");
165 }else if( rc
==SQLITE_OK
){
167 pNew
->pSchema
= sqlite3SchemaGet(db
, pNew
->pBt
);
168 if( !pNew
->pSchema
){
169 rc
= SQLITE_NOMEM_BKPT
;
170 }else if( pNew
->pSchema
->file_format
&& pNew
->pSchema
->enc
!=ENC(db
) ){
171 zErrDyn
= sqlite3MPrintf(db
,
172 "attached databases must use the same text encoding as main database");
175 sqlite3BtreeEnter(pNew
->pBt
);
176 pPager
= sqlite3BtreePager(pNew
->pBt
);
177 sqlite3PagerLockingMode(pPager
, db
->dfltLockMode
);
178 sqlite3BtreeSecureDelete(pNew
->pBt
,
179 sqlite3BtreeSecureDelete(db
->aDb
[0].pBt
,-1) );
180 #ifndef SQLITE_OMIT_PAGER_PRAGMAS
181 sqlite3BtreeSetPagerFlags(pNew
->pBt
,
182 PAGER_SYNCHRONOUS_FULL
| (db
->flags
& PAGER_FLAGS_MASK
));
184 sqlite3BtreeLeave(pNew
->pBt
);
186 pNew
->safety_level
= SQLITE_DEFAULT_SYNCHRONOUS
+1;
187 if( !REOPEN_AS_MEMDB(db
) ) pNew
->zDbSName
= sqlite3DbStrDup(db
, zName
);
188 if( rc
==SQLITE_OK
&& pNew
->zDbSName
==0 ){
189 rc
= SQLITE_NOMEM_BKPT
;
193 #ifdef SQLITE_HAS_CODEC
195 extern int sqlite3CodecAttach(sqlite3
*, int, const void*, int);
196 extern void sqlite3CodecGetKey(sqlite3
*, int, void**, int*);
199 int t
= sqlite3_value_type(argv
[2]);
203 zErrDyn
= sqlite3DbStrDup(db
, "Invalid key value");
209 nKey
= sqlite3_value_bytes(argv
[2]);
210 zKey
= (char *)sqlite3_value_blob(argv
[2]);
211 rc
= sqlite3CodecAttach(db
, db
->nDb
-1, zKey
, nKey
);
215 /* No key specified. Use the key from the main database */
216 sqlite3CodecGetKey(db
, 0, (void**)&zKey
, &nKey
);
217 if( nKey
|| sqlite3BtreeGetOptimalReserve(db
->aDb
[0].pBt
)>0 ){
218 rc
= sqlite3CodecAttach(db
, db
->nDb
-1, zKey
, nKey
);
225 /* If the file was opened successfully, read the schema for the new database.
226 ** If this fails, or if opening the file failed, then close the file and
227 ** remove the entry from the db->aDb[] array. i.e. put everything back the
231 sqlite3BtreeEnterAll(db
);
233 rc
= sqlite3Init(db
, &zErrDyn
);
234 sqlite3BtreeLeaveAll(db
);
235 assert( zErrDyn
==0 || rc
!=SQLITE_OK
);
237 #ifdef SQLITE_USER_AUTHENTICATION
240 rc
= sqlite3UserAuthCheckLogin(db
, zName
, &newAuth
);
241 if( newAuth
<db
->auth
.authLevel
){
242 rc
= SQLITE_AUTH_USER
;
247 if( !REOPEN_AS_MEMDB(db
) ){
248 int iDb
= db
->nDb
- 1;
250 if( db
->aDb
[iDb
].pBt
){
251 sqlite3BtreeClose(db
->aDb
[iDb
].pBt
);
252 db
->aDb
[iDb
].pBt
= 0;
253 db
->aDb
[iDb
].pSchema
= 0;
255 sqlite3ResetAllSchemasOfConnection(db
);
257 if( rc
==SQLITE_NOMEM
|| rc
==SQLITE_IOERR_NOMEM
){
259 sqlite3DbFree(db
, zErrDyn
);
260 zErrDyn
= sqlite3MPrintf(db
, "out of memory");
261 }else if( zErrDyn
==0 ){
262 zErrDyn
= sqlite3MPrintf(db
, "unable to open database: %s", zFile
);
271 /* Return an error if we get here */
273 sqlite3_result_error(context
, zErrDyn
, -1);
274 sqlite3DbFree(db
, zErrDyn
);
276 if( rc
) sqlite3_result_error_code(context
, rc
);
280 ** An SQL user-function registered to do the work of an DETACH statement. The
281 ** three arguments to the function come directly from a detach statement:
285 ** SELECT sqlite_detach(x)
287 static void detachFunc(
288 sqlite3_context
*context
,
292 const char *zName
= (const char *)sqlite3_value_text(argv
[0]);
293 sqlite3
*db
= sqlite3_context_db_handle(context
);
298 UNUSED_PARAMETER(NotUsed
);
300 if( zName
==0 ) zName
= "";
301 for(i
=0; i
<db
->nDb
; i
++){
303 if( pDb
->pBt
==0 ) continue;
304 if( sqlite3StrICmp(pDb
->zDbSName
, zName
)==0 ) break;
308 sqlite3_snprintf(sizeof(zErr
),zErr
, "no such database: %s", zName
);
312 sqlite3_snprintf(sizeof(zErr
),zErr
, "cannot detach database %s", zName
);
315 if( sqlite3BtreeIsInReadTrans(pDb
->pBt
) || sqlite3BtreeIsInBackup(pDb
->pBt
) ){
316 sqlite3_snprintf(sizeof(zErr
),zErr
, "database %s is locked", zName
);
320 sqlite3BtreeClose(pDb
->pBt
);
323 sqlite3CollapseDatabaseArray(db
);
327 sqlite3_result_error(context
, zErr
, -1);
331 ** This procedure generates VDBE code for a single invocation of either the
332 ** sqlite_detach() or sqlite_attach() SQL user functions.
334 static void codeAttach(
335 Parse
*pParse
, /* The parser context */
336 int type
, /* Either SQLITE_ATTACH or SQLITE_DETACH */
337 FuncDef
const *pFunc
,/* FuncDef wrapper for detachFunc() or attachFunc() */
338 Expr
*pAuthArg
, /* Expression to pass to authorization callback */
339 Expr
*pFilename
, /* Name of database file */
340 Expr
*pDbname
, /* Name of the database to use internally */
341 Expr
*pKey
/* Database key for encryption extension */
346 sqlite3
* db
= pParse
->db
;
349 if( pParse
->nErr
) goto attach_end
;
350 memset(&sName
, 0, sizeof(NameContext
));
351 sName
.pParse
= pParse
;
354 SQLITE_OK
!=(rc
= resolveAttachExpr(&sName
, pFilename
)) ||
355 SQLITE_OK
!=(rc
= resolveAttachExpr(&sName
, pDbname
)) ||
356 SQLITE_OK
!=(rc
= resolveAttachExpr(&sName
, pKey
))
361 #ifndef SQLITE_OMIT_AUTHORIZATION
364 if( pAuthArg
->op
==TK_STRING
){
365 zAuthArg
= pAuthArg
->u
.zToken
;
369 rc
= sqlite3AuthCheck(pParse
, type
, zAuthArg
, 0, 0);
374 #endif /* SQLITE_OMIT_AUTHORIZATION */
377 v
= sqlite3GetVdbe(pParse
);
378 regArgs
= sqlite3GetTempRange(pParse
, 4);
379 sqlite3ExprCode(pParse
, pFilename
, regArgs
);
380 sqlite3ExprCode(pParse
, pDbname
, regArgs
+1);
381 sqlite3ExprCode(pParse
, pKey
, regArgs
+2);
383 assert( v
|| db
->mallocFailed
);
385 sqlite3VdbeAddOp4(v
, OP_Function0
, 0, regArgs
+3-pFunc
->nArg
, regArgs
+3,
386 (char *)pFunc
, P4_FUNCDEF
);
387 assert( pFunc
->nArg
==-1 || (pFunc
->nArg
&0xff)==pFunc
->nArg
);
388 sqlite3VdbeChangeP5(v
, (u8
)(pFunc
->nArg
));
390 /* Code an OP_Expire. For an ATTACH statement, set P1 to true (expire this
391 ** statement only). For DETACH, set it to false (expire all existing
394 sqlite3VdbeAddOp1(v
, OP_Expire
, (type
==SQLITE_ATTACH
));
398 sqlite3ExprDelete(db
, pFilename
);
399 sqlite3ExprDelete(db
, pDbname
);
400 sqlite3ExprDelete(db
, pKey
);
404 ** Called by the parser to compile a DETACH statement.
408 void sqlite3Detach(Parse
*pParse
, Expr
*pDbname
){
409 static const FuncDef detach_func
= {
411 SQLITE_UTF8
, /* funcFlags */
414 detachFunc
, /* xSFunc */
416 "sqlite_detach", /* zName */
419 codeAttach(pParse
, SQLITE_DETACH
, &detach_func
, pDbname
, 0, 0, pDbname
);
423 ** Called by the parser to compile an ATTACH statement.
425 ** ATTACH p AS pDbname KEY pKey
427 void sqlite3Attach(Parse
*pParse
, Expr
*p
, Expr
*pDbname
, Expr
*pKey
){
428 static const FuncDef attach_func
= {
430 SQLITE_UTF8
, /* funcFlags */
433 attachFunc
, /* xSFunc */
435 "sqlite_attach", /* zName */
438 codeAttach(pParse
, SQLITE_ATTACH
, &attach_func
, p
, p
, pDbname
, pKey
);
440 #endif /* SQLITE_OMIT_ATTACH */
443 ** Initialize a DbFixer structure. This routine must be called prior
444 ** to passing the structure to one of the sqliteFixAAAA() routines below.
447 DbFixer
*pFix
, /* The fixer to be initialized */
448 Parse
*pParse
, /* Error messages will be written here */
449 int iDb
, /* This is the database that must be used */
450 const char *zType
, /* "view", "trigger", or "index" */
451 const Token
*pName
/* Name of the view, trigger, or index */
456 assert( db
->nDb
>iDb
);
457 pFix
->pParse
= pParse
;
458 pFix
->zDb
= db
->aDb
[iDb
].zDbSName
;
459 pFix
->pSchema
= db
->aDb
[iDb
].pSchema
;
462 pFix
->bVarOnly
= (iDb
==1);
466 ** The following set of routines walk through the parse tree and assign
467 ** a specific database to all table references where the database name
468 ** was left unspecified in the original SQL statement. The pFix structure
469 ** must have been initialized by a prior call to sqlite3FixInit().
471 ** These routines are used to make sure that an index, trigger, or
472 ** view in one database does not refer to objects in a different database.
473 ** (Exception: indices, triggers, and views in the TEMP database are
474 ** allowed to refer to anything.) If a reference is explicitly made
475 ** to an object in a different database, an error message is added to
476 ** pParse->zErrMsg and these routines return non-zero. If everything
477 ** checks out, these routines return 0.
479 int sqlite3FixSrcList(
480 DbFixer
*pFix
, /* Context of the fixation */
481 SrcList
*pList
/* The Source list to check and modify */
485 struct SrcList_item
*pItem
;
487 if( NEVER(pList
==0) ) return 0;
489 for(i
=0, pItem
=pList
->a
; i
<pList
->nSrc
; i
++, pItem
++){
490 if( pFix
->bVarOnly
==0 ){
491 if( pItem
->zDatabase
&& sqlite3StrICmp(pItem
->zDatabase
, zDb
) ){
492 sqlite3ErrorMsg(pFix
->pParse
,
493 "%s %T cannot reference objects in database %s",
494 pFix
->zType
, pFix
->pName
, pItem
->zDatabase
);
497 sqlite3DbFree(pFix
->pParse
->db
, pItem
->zDatabase
);
498 pItem
->zDatabase
= 0;
499 pItem
->pSchema
= pFix
->pSchema
;
501 #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER)
502 if( sqlite3FixSelect(pFix
, pItem
->pSelect
) ) return 1;
503 if( sqlite3FixExpr(pFix
, pItem
->pOn
) ) return 1;
508 #if !defined(SQLITE_OMIT_VIEW) || !defined(SQLITE_OMIT_TRIGGER)
509 int sqlite3FixSelect(
510 DbFixer
*pFix
, /* Context of the fixation */
511 Select
*pSelect
/* The SELECT statement to be fixed to one database */
514 if( sqlite3FixExprList(pFix
, pSelect
->pEList
) ){
517 if( sqlite3FixSrcList(pFix
, pSelect
->pSrc
) ){
520 if( sqlite3FixExpr(pFix
, pSelect
->pWhere
) ){
523 if( sqlite3FixExprList(pFix
, pSelect
->pGroupBy
) ){
526 if( sqlite3FixExpr(pFix
, pSelect
->pHaving
) ){
529 if( sqlite3FixExprList(pFix
, pSelect
->pOrderBy
) ){
532 if( sqlite3FixExpr(pFix
, pSelect
->pLimit
) ){
535 if( pSelect
->pWith
){
537 for(i
=0; i
<pSelect
->pWith
->nCte
; i
++){
538 if( sqlite3FixSelect(pFix
, pSelect
->pWith
->a
[i
].pSelect
) ){
543 pSelect
= pSelect
->pPrior
;
548 DbFixer
*pFix
, /* Context of the fixation */
549 Expr
*pExpr
/* The expression to be fixed to one database */
552 if( pExpr
->op
==TK_VARIABLE
){
553 if( pFix
->pParse
->db
->init
.busy
){
556 sqlite3ErrorMsg(pFix
->pParse
, "%s cannot use variables", pFix
->zType
);
560 if( ExprHasProperty(pExpr
, EP_TokenOnly
|EP_Leaf
) ) break;
561 if( ExprHasProperty(pExpr
, EP_xIsSelect
) ){
562 if( sqlite3FixSelect(pFix
, pExpr
->x
.pSelect
) ) return 1;
564 if( sqlite3FixExprList(pFix
, pExpr
->x
.pList
) ) return 1;
566 if( sqlite3FixExpr(pFix
, pExpr
->pRight
) ){
569 pExpr
= pExpr
->pLeft
;
573 int sqlite3FixExprList(
574 DbFixer
*pFix
, /* Context of the fixation */
575 ExprList
*pList
/* The expression to be fixed to one database */
578 struct ExprList_item
*pItem
;
579 if( pList
==0 ) return 0;
580 for(i
=0, pItem
=pList
->a
; i
<pList
->nExpr
; i
++, pItem
++){
581 if( sqlite3FixExpr(pFix
, pItem
->pExpr
) ){
589 #ifndef SQLITE_OMIT_TRIGGER
590 int sqlite3FixTriggerStep(
591 DbFixer
*pFix
, /* Context of the fixation */
592 TriggerStep
*pStep
/* The trigger step be fixed to one database */
595 if( sqlite3FixSelect(pFix
, pStep
->pSelect
) ){
598 if( sqlite3FixExpr(pFix
, pStep
->pWhere
) ){
601 if( sqlite3FixExprList(pFix
, pStep
->pExprList
) ){
604 pStep
= pStep
->pNext
;