SQLite

**
*************************************************************************
** Main file for the SQLite library.  The routines in this file
** implement the programmer interface to the library.  Routines in
** other files are for internal use by SQLite and should not be
** accessed by users of the library.
**
** $Id: main.c,v 1.164.2.1 2004/06/19 04:23:25 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>

/*
** A pointer to this structure is used to communicate information

** indicate success or failure.
*/
static int sqliteInitOne(sqlite *db, int iDb, char **pzErrMsg){
  int rc;
  BtCursor *curMain;
  int size;
  Table *pTab;
  char const *azArg[6];
  char zDbNum[30];
  int meta[SQLITE_N_BTREE_META];
  InitData initData;
  char const *zMasterSchema;
  char const *zMasterName;
  char *zSql = 0;

  /*
  ** The master database table has a structure like this
  */
  static char master_schema[] = 
     "CREATE TABLE sqlite_master(\n"
     "  type text,\n"

     "  name text,\n"
     "  tbl_name text,\n"
     "  rootpage integer,\n"
     "  sql text\n"
     ")"
  ;

  assert( iDb>=0 && iDb<db->nDb );

  /* zMasterSchema and zInitScript are set to point at the master schema




  ** and initialisation script appropriate for the database being





  ** initialised. zMasterName is the name of the master table.
  */
  if( iDb==1 ){
    zMasterSchema = temp_master_schema;

    zMasterName = TEMP_MASTER_NAME;



  }else{
    zMasterSchema = master_schema;




    zMasterName = MASTER_NAME;
  }


  /* Construct the schema table.
  */
  sqliteSafetyOff(db);
  azArg[0] = "table";
  azArg[1] = zMasterName;
  azArg[2] = "2";
  azArg[3] = zMasterSchema;
  sprintf(zDbNum, "%d", iDb);
  azArg[4] = zDbNum;
  azArg[5] = 0;
  initData.db = db;
  initData.pzErrMsg = pzErrMsg;
  sqliteInitCallback(&initData, 5, (char **)azArg, 0);
  pTab = sqliteFindTable(db, zMasterName, db->aDb[iDb].zName);
  if( pTab ){
    pTab->readOnly = 1;
  }else{







    return SQLITE_NOMEM;

  }
  sqliteSafetyOn(db);

  /* Create a cursor to hold the database open
  */
  if( db->aDb[iDb].pBt==0 ) return SQLITE_OK;
  rc = sqliteBtreeCursor(db->aDb[iDb].pBt, 2, 0, &curMain);

      /* This happens if the database was initially empty */
      db->file_format = 4;
    }else if( db->file_format>4 ){
      sqliteBtreeCloseCursor(curMain);
      sqliteSetString(pzErrMsg, "unsupported file format", (char*)0);
      return SQLITE_ERROR;
    }
  }else if( iDb!=1 && (db->file_format!=meta[2] || db->file_format<4) ){
    assert( db->file_format>=4 );
    if( meta[2]==0 ){
      sqliteSetString(pzErrMsg, "cannot attach empty database: ",
         db->aDb[iDb].zName, (char*)0);
    }else{
      sqliteSetString(pzErrMsg, "incompatible file format in auxiliary "
         "database: ", db->aDb[iDb].zName, (char*)0);
    }
    sqliteBtreeClose(db->aDb[iDb].pBt);
    db->aDb[iDb].pBt = 0;
    return SQLITE_FORMAT;
  }
  sqliteBtreeSetCacheSize(db->aDb[iDb].pBt, db->cache_size);
  sqliteBtreeSetSafetyLevel(db->aDb[iDb].pBt, meta[4]==0 ? 2 : meta[4]);

  /* Read the schema information out of the schema tables
  */
  assert( db->init.busy );
  sqliteSafetyOff(db);

  /* The following SQL will read the schema from the master tables.
  ** The first version works with SQLite file formats 2 or greater.
  ** The second version is for format 1 files.
  **
  ** Beginning with file format 2, the rowid for new table entries
  ** (including entries in sqlite_master) is an increasing integer.
  ** So for file format 2 and later, we can play back sqlite_master
  ** and all the CREATE statements will appear in the right order.
  ** But with file format 1, table entries were random and so we
  ** have to make sure the CREATE TABLEs occur before their corresponding
  ** CREATE INDEXs.  (We don't have to deal with CREATE VIEW or
  ** CREATE TRIGGER in file format 1 because those constructs did
  ** not exist then.) 
  */
  if( db->file_format>=2 ){
    sqliteSetString(&zSql, 
        "SELECT type, name, rootpage, sql, ", zDbNum, " FROM \"",
       db->aDb[iDb].zName, "\".", zMasterName, (char*)0);
  }else{

    sqliteSetString(&zSql, 
        "SELECT type, name, rootpage, sql, ", zDbNum, " FROM \"",
       db->aDb[iDb].zName, "\".", zMasterName, 
       " WHERE type IN ('table', 'index')"
       " ORDER BY CASE type WHEN 'table' THEN 0 ELSE 1 END", (char*)0);
  }
  rc = sqlite_exec(db, zSql, sqliteInitCallback, &initData, 0);


  sqliteFree(zSql);
  sqliteSafetyOn(db);
  sqliteBtreeCloseCursor(curMain);
  if( sqlite_malloc_failed ){
    sqliteSetString(pzErrMsg, "out of memory", (char*)0);
    rc = SQLITE_NOMEM;
    sqliteResetInternalSchema(db, 0);
  }
  if( rc==SQLITE_OK ){
    DbSetProperty(db, iDb, DB_SchemaLoaded);



  }else{
    sqliteResetInternalSchema(db, iDb);
  }
  return rc;
}

/*

  int i, rc;
  
  if( db->init.busy ) return SQLITE_OK;
  assert( (db->flags & SQLITE_Initialized)==0 );
  rc = SQLITE_OK;
  db->init.busy = 1;
  for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
    if( DbHasProperty(db, i, DB_SchemaLoaded) || i==1 ) continue;

    rc = sqliteInitOne(db, i, pzErrMsg);
    if( rc ){
      sqliteResetInternalSchema(db, i);
    }
  }

  /* Once all the other databases have been initialised, load the schema
  ** for the TEMP database. This is loaded last, as the TEMP database
  ** schema may contain references to objects in other databases.
  */
  if( rc==SQLITE_OK && db->nDb>1 && !DbHasProperty(db, 1, DB_SchemaLoaded) ){
    rc = sqliteInitOne(db, 1, pzErrMsg);
    if( rc ){
      sqliteResetInternalSchema(db, 1);
    }
  }

  db->init.busy = 0;
  if( rc==SQLITE_OK ){
    db->flags |= SQLITE_Initialized;
    sqliteCommitInternalChanges(db);
  }

  /* If the database is in formats 1 or 2, then upgrade it to

do_test trigger-9.2 {
  execsql {
    INSERT INTO t3 VALUES(1,3);
    SELECT * FROM t3 UNION ALL SELECT 99, 99 UNION ALL SELECT * FROM t4;
  }
} {1 2 1 3 99 99 1 3}

execsql {
  DROP TABLE t2;
  DROP TABLE t3;
  DROP TABLE t4;
}

# Ticket #764. At one stage TEMP triggers would fail to re-install when the
# schema was reloaded. The following tests ensure that TEMP triggers are
# correctly re-installed.
#
# Also verify that references within trigger programs are resolved at
# statement compile time, not trigger installation time. This means, for
# example, that you can drop and re-create tables referenced by triggers. 
do_test trigger-10.0 {
  file delete -force test2.db
  file delete -force test2.db-journal
  sqlite db2 test2.db
  execsql {CREATE TABLE t3(a, b, c);} db2
  db2 close
  execsql {
    ATTACH 'test2.db' AS aux;
  }
} {}
do_test trigger-10.1 {
  execsql {
    CREATE TABLE t1(a, b, c);
    CREATE temp TABLE t2(a, b, c);
    CREATE TABLE insert_log(db, a, b, c);
  }
} {}
do_test trigger-10.2 {
  execsql {
    CREATE TEMP TRIGGER trig1 AFTER INSERT ON t1 BEGIN 
      INSERT INTO insert_log VALUES('main', new.a, new.b, new.c);
    END;
    CREATE TEMP TRIGGER trig2 AFTER INSERT ON t2 BEGIN 
      INSERT INTO insert_log VALUES('temp', new.a, new.b, new.c);
    END;
    CREATE TEMP TRIGGER trig3 AFTER INSERT ON t3 BEGIN 
      INSERT INTO insert_log VALUES('aux', new.a, new.b, new.c);
    END;
  }
} {}
do_test trigger-10.3 {
  execsql {
    INSERT INTO t1 VALUES(1, 2, 3);
    INSERT INTO t2 VALUES(4, 5, 6);
    INSERT INTO t3  VALUES(7, 8, 9);
  }
} {}
do_test trigger-10.4 {
  execsql {
    SELECT * FROM insert_log;
  }
} {main 1 2 3 temp 4 5 6 aux 7 8 9}
do_test trigger-10.5 {
  execsql {
    BEGIN;
    INSERT INTO t1 VALUES(1, 2, 3);
    INSERT INTO t2 VALUES(4, 5, 6);
    INSERT INTO t3  VALUES(7, 8, 9);
    ROLLBACK;
  }
} {}
do_test trigger-10.6 {
  execsql {
    SELECT * FROM insert_log;
  }
} {main 1 2 3 temp 4 5 6 aux 7 8 9}
do_test trigger-10.7 {
  execsql {
    DELETE FROM insert_log;
    INSERT INTO t1 VALUES(11, 12, 13);
    INSERT INTO t2 VALUES(14, 15, 16);
    INSERT INTO t3 VALUES(17, 18, 19);
  }
} {}
do_test trigger-10.8 {
  execsql {
    SELECT * FROM insert_log;
  }
} {main 11 12 13 temp 14 15 16 aux 17 18 19}
do_test trigger-10.8 {
# Drop and re-create the insert_log table in a different database. Note
# that we can change the column names because the trigger programs don't
# use them explicitly.
  execsql {
    DROP TABLE insert_log;
    CREATE temp TABLE insert_log(db, d, e, f);
  }
} {}
do_test trigger-10.10 {
  execsql {
    INSERT INTO t1 VALUES(21, 22, 23);
    INSERT INTO t2 VALUES(24, 25, 26);
    INSERT INTO t3  VALUES(27, 28, 29);
  }
} {}
do_test trigger-10.11 {
  execsql {
    SELECT * FROM insert_log;
  }
} {main 21 22 23 temp 24 25 26 aux 27 28 29}

finish_test