**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.396 2006/06/11 23:41:55 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Initialize the pParse structure as needed.
................................................................................
      goto begin_table_error;
    }
  }
#endif

  /* Make sure the new table name does not collide with an existing
  ** index or table name in the same database.  Issue an error message if
  ** it does.



  */

  if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
    goto begin_table_error;
  }
  pTable = sqlite3FindTable(db, zName, db->aDb[iDb].zName);
  if( pTable ){
    if( !noErr ){
      sqlite3ErrorMsg(pParse, "table %T already exists", pName);
    }
    goto begin_table_error;
  }
  if( sqlite3FindIndex(db, zName, 0)!=0 && (iDb==0 || !db->init.busy) ){
    sqlite3ErrorMsg(pParse, "there is already an index named %s", zName);
    goto begin_table_error;
  }


  pTable = sqliteMalloc( sizeof(Table) );
  if( pTable==0 ){
    pParse->rc = SQLITE_NOMEM;
    pParse->nErr++;
    goto begin_table_error;
  }
  pTable->zName = zName;
................................................................................

  assert( pTable );

  /* A positive nCol means the columns names for this view are
  ** already known.
  */
  if( pTable->nCol>0 ) return 0;




  /* A negative nCol is a special marker meaning that we are currently
  ** trying to compute the column names.  If we enter this routine with
  ** a negative nCol, it means two or more views form a loop, like this:
  **
  **     CREATE VIEW one AS SELECT * FROM two;
  **     CREATE VIEW two AS SELECT * FROM one;

**     CREATE INDEX
**     DROP INDEX
**     creating ID lists
**     BEGIN TRANSACTION
**     COMMIT
**     ROLLBACK
**
** $Id: build.c,v 1.397 2006/06/12 11:24:37 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** This routine is called when a new SQL statement is beginning to
** be parsed.  Initialize the pParse structure as needed.
................................................................................
      goto begin_table_error;
    }
  }
#endif

  /* Make sure the new table name does not collide with an existing
  ** index or table name in the same database.  Issue an error message if
  ** it does. The exception is if the statement being parsed was passed
  ** to an sqlite3_declare_vtab() call. In that case only the column names
  ** and types will be used, so there is no need to test for namespace
  ** collisions.
  */
  if( !IN_DECLARE_VTAB ){
    if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){
      goto begin_table_error;
    }
    pTable = sqlite3FindTable(db, zName, db->aDb[iDb].zName);
    if( pTable ){
      if( !noErr ){
        sqlite3ErrorMsg(pParse, "table %T already exists", pName);
      }
      goto begin_table_error;
    }
    if( sqlite3FindIndex(db, zName, 0)!=0 && (iDb==0 || !db->init.busy) ){
      sqlite3ErrorMsg(pParse, "there is already an index named %s", zName);
      goto begin_table_error;
    }
  }

  pTable = sqliteMalloc( sizeof(Table) );
  if( pTable==0 ){
    pParse->rc = SQLITE_NOMEM;
    pParse->nErr++;
    goto begin_table_error;
  }
  pTable->zName = zName;
................................................................................

  assert( pTable );

  /* A positive nCol means the columns names for this view are
  ** already known.
  */
  if( pTable->nCol>0 ) return 0;
#ifndef SQLITE_OMIT_VIRTUALTABLE
  if( pTable->isVirtual ) return 0;
#endif

  /* A negative nCol is a special marker meaning that we are currently
  ** trying to compute the column names.  If we enter this routine with
  ** a negative nCol, it means two or more views form a loop, like this:
  **
  **     CREATE VIEW one AS SELECT * FROM two;
  **     CREATE VIEW two AS SELECT * FROM one;

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the SQLite library
** presents to client programs.
**
** @(#) $Id: sqlite.h.in,v 1.168 2006/06/11 23:41:56 drh Exp $
*/
#ifndef _SQLITE3_H_
#define _SQLITE3_H_
#include <stdarg.h>     /* Needed for the definition of va_list */

/*
** Make sure we can call this stuff from C++.
................................................................................
#define SQLITE_INDEX_CONSTRAINT_MATCH 7
int sqlite3_create_module(
  sqlite3 *db, 
  const char *zName,
  const sqlite3_module *
);



/*
** Undo the hack that converts floating point types to integer for
** builds on processors without floating point support.
*/
#ifdef SQLITE_OMIT_FLOATING_POINT
# undef double
#endif

#ifdef __cplusplus
}  /* End of the 'extern "C"' block */
#endif
#endif

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This header file defines the interface that the SQLite library
** presents to client programs.
**
** @(#) $Id: sqlite.h.in,v 1.169 2006/06/12 11:24:37 danielk1977 Exp $
*/
#ifndef _SQLITE3_H_
#define _SQLITE3_H_
#include <stdarg.h>     /* Needed for the definition of va_list */

/*
** Make sure we can call this stuff from C++.
................................................................................
#define SQLITE_INDEX_CONSTRAINT_MATCH 7
int sqlite3_create_module(
  sqlite3 *db, 
  const char *zName,
  const sqlite3_module *
);

int sqlite3_declare_vtab(sqlite3*, const char *zCreateTable);

/*
** Undo the hack that converts floating point types to integer for
** builds on processors without floating point support.
*/
#ifdef SQLITE_OMIT_FLOATING_POINT
# undef double
#endif

#ifdef __cplusplus
}  /* End of the 'extern "C"' block */
#endif
#endif

**    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.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.498 2006/06/12 06:09:18 danielk1977 Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

/*
** Extra interface definitions for those who need them
*/
................................................................................
#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
  int (*xProgress)(void *);     /* The progress callback */
  void *pProgressArg;           /* Argument to the progress callback */
  int nProgressOps;             /* Number of opcodes for progress callback */
#endif
#ifndef SQLITE_OMIT_VIRTUALTABLE
  Hash aModule;                 /* populated by sqlite3_create_module() */

#endif
  Hash aFunc;                   /* All functions that can be in SQL exprs */
  Hash aCollSeq;                /* All collating sequences */
  BusyHandler busyHandler;      /* Busy callback */
  int busyTimeout;              /* Busy handler timeout, in msec */
  Db aDbStatic[2];              /* Static space for the 2 default backends */
#ifdef SQLITE_SSE
................................................................................
  Trigger *pNewTrigger;     /* Trigger under construct by a CREATE TRIGGER */
  TriggerStack *trigStack;  /* Trigger actions being coded */
  const char *zAuthContext; /* The 6th parameter to db->xAuth callbacks */
#ifndef SQLITE_OMIT_VIRTUALTABLE
  int nArgAlloc;            /* Number of bytes allocated for zArg[] */
  int nArgUsed;             /* Number of bytes of zArg[] used so far */
  char *zArg;               /* Complete text of a module argument */

#endif
};







/*
** An instance of the following structure can be declared on a stack and used
** to save the Parse.zAuthContext value so that it can be restored later.
*/
struct AuthContext {
  const char *zAuthContext;   /* Put saved Parse.zAuthContext here */
................................................................................
   void sqlite3VtabClear(Table*);
#endif
void sqlite3VtabBeginParse(Parse*, Token*, Token*, Token*);
void sqlite3VtabFinishParse(Parse*, Token*);
void sqlite3VtabArgInit(Parse*);
void sqlite3VtabArgExtend(Parse*, Token*);
int sqlite3VtabCallCreate(sqlite3*, int, const char *, char **);


#ifdef SQLITE_SSE
#include "sseInt.h"
#endif

#endif

**    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.
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.499 2006/06/12 11:24:37 danielk1977 Exp $
*/
#ifndef _SQLITEINT_H_
#define _SQLITEINT_H_

/*
** Extra interface definitions for those who need them
*/
................................................................................
#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
  int (*xProgress)(void *);     /* The progress callback */
  void *pProgressArg;           /* Argument to the progress callback */
  int nProgressOps;             /* Number of opcodes for progress callback */
#endif
#ifndef SQLITE_OMIT_VIRTUALTABLE
  Hash aModule;                 /* populated by sqlite3_create_module() */
  Table *pVTab;                 /* vtab with active Connect/Create method */
#endif
  Hash aFunc;                   /* All functions that can be in SQL exprs */
  Hash aCollSeq;                /* All collating sequences */
  BusyHandler busyHandler;      /* Busy callback */
  int busyTimeout;              /* Busy handler timeout, in msec */
  Db aDbStatic[2];              /* Static space for the 2 default backends */
#ifdef SQLITE_SSE
................................................................................
  Trigger *pNewTrigger;     /* Trigger under construct by a CREATE TRIGGER */
  TriggerStack *trigStack;  /* Trigger actions being coded */
  const char *zAuthContext; /* The 6th parameter to db->xAuth callbacks */
#ifndef SQLITE_OMIT_VIRTUALTABLE
  int nArgAlloc;            /* Number of bytes allocated for zArg[] */
  int nArgUsed;             /* Number of bytes of zArg[] used so far */
  char *zArg;               /* Complete text of a module argument */
  u8 declareVtab;           /* True if inside sqlite3_declare_vtab() */
#endif
};

#ifdef SQLITE_OMIT_VIRTUALTABLE
  #define IN_DECLARE_VTAB 0
#else
  #define IN_DECLARE_VTAB (pParse->declareVtab)
#endif

/*
** An instance of the following structure can be declared on a stack and used
** to save the Parse.zAuthContext value so that it can be restored later.
*/
struct AuthContext {
  const char *zAuthContext;   /* Put saved Parse.zAuthContext here */
................................................................................
   void sqlite3VtabClear(Table*);
#endif
void sqlite3VtabBeginParse(Parse*, Token*, Token*, Token*);
void sqlite3VtabFinishParse(Parse*, Token*);
void sqlite3VtabArgInit(Parse*);
void sqlite3VtabArgExtend(Parse*, Token*);
int sqlite3VtabCallCreate(sqlite3*, int, const char *, char **);
int sqlite3VtabCallConnect(Parse*, Table*);

#ifdef SQLITE_SSE
#include "sseInt.h"
#endif

#endif

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing the virtual table interfaces.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test8.c,v 1.2 2006/06/12 06:09:19 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"
#include "os.h"
#include <stdlib.h>
#include <string.h>

................................................................................
** Global Tcl variable $echo_module is a list. This routine appends
** the string element zArg to that list in interpreter interp.
*/
static void appendToEchoModule(const sqlite3_module *pModule, const char *zArg){
  int flags = (TCL_APPEND_VALUE | TCL_LIST_ELEMENT | TCL_GLOBAL_ONLY);
  Tcl_SetVar((Tcl_Interp *)(pModule->pAux), "echo_module", zArg, flags);
}







































/* Methods for the echo module */
static int echoCreate(
  sqlite3 *db,
  const sqlite3_module *pModule,
  int argc, char **argv,
  sqlite3_vtab **ppVtab
){
  int i;
  Tcl_Interp *interp = pModule->pAux;
  *ppVtab = pModule->pAux;

  appendToEchoModule(pModule, "xCreate");
  for(i=0; i<argc; i++){
    appendToEchoModule(pModule, argv[i]);
  }


  return 0;
}
static int echoConnect(
  sqlite3 *db,
  const sqlite3_module *pModule,
  int argc, char **argv,
  sqlite3_vtab **ppVtab
................................................................................
  *ppVtab = pModule->pAux;

  Tcl_SetVar(interp, "echo_module", "xConnect", TCL_GLOBAL_ONLY);
  for(i=0; i<argc; i++){
    Tcl_SetVar(interp, "echo_module", argv[i],
                TCL_APPEND_VALUE | TCL_LIST_ELEMENT | TCL_GLOBAL_ONLY);
  }


  return 0;
}
static int echoDisconnect(sqlite3_vtab *pVtab){
  Tcl_Interp *interp = (Tcl_Interp*)pVtab;
  Tcl_SetVar(interp, "echo_module", "xDisconnect",
                TCL_APPEND_VALUE | TCL_LIST_ELEMENT | TCL_GLOBAL_ONLY);
  return 0;

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing the virtual table interfaces.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test8.c,v 1.3 2006/06/12 11:24:37 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "tcl.h"
#include "os.h"
#include <stdlib.h>
#include <string.h>

................................................................................
** Global Tcl variable $echo_module is a list. This routine appends
** the string element zArg to that list in interpreter interp.
*/
static void appendToEchoModule(const sqlite3_module *pModule, const char *zArg){
  int flags = (TCL_APPEND_VALUE | TCL_LIST_ELEMENT | TCL_GLOBAL_ONLY);
  Tcl_SetVar((Tcl_Interp *)(pModule->pAux), "echo_module", zArg, flags);
}

/*
** This function is called from within the echo-modules xCreate and
** xConnect methods. The argc and argv arguments are copies of those 
** passed to the calling method. This function is responsible for
** calling sqlite3_declare_vtab() to declare the schema of the virtual
** table being created or connected.
**
** If the constructor was passed just one argument, i.e.:
**
**   CREATE TABLE t1 AS echo(t2);
**
** Then t2 is assumed to be the name of a *real* database table. The
** schema of the virtual table is declared by passing a copy of the 
** CREATE TABLE statement for the real table to sqlite3_declare_vtab().
** Hence, the virtual table should have exactly the same column names and 
** types as the real table.
*/
static int echoDeclareVtab(sqlite3 *db, int argc, char **argv){
  int rc = SQLITE_OK;

  if( argc==2 ){
    sqlite3_stmt *pStmt = 0;
    sqlite3_prepare(db, 
        "SELECT sql FROM sqlite_master WHERE type = 'table' AND name = ?",
        -1, &pStmt, 0);
    sqlite3_bind_text(pStmt, 1, argv[1], -1, 0);
    if( sqlite3_step(pStmt)==SQLITE_ROW ){
      const char *zCreateTable = sqlite3_column_text(pStmt, 0);
      sqlite3_declare_vtab(db, zCreateTable);
    } else {
      rc = SQLITE_ERROR;
    }
    sqlite3_finalize(pStmt);
  }

  return rc;
}

/* Methods for the echo module */
static int echoCreate(
  sqlite3 *db,
  const sqlite3_module *pModule,
  int argc, char **argv,
  sqlite3_vtab **ppVtab
){
  int i;

  *ppVtab = pModule->pAux;

  appendToEchoModule(pModule, "xCreate");
  for(i=0; i<argc; i++){
    appendToEchoModule(pModule, argv[i]);
  }

  echoDeclareVtab(db, argc, argv);
  return 0;
}
static int echoConnect(
  sqlite3 *db,
  const sqlite3_module *pModule,
  int argc, char **argv,
  sqlite3_vtab **ppVtab
................................................................................
  *ppVtab = pModule->pAux;

  Tcl_SetVar(interp, "echo_module", "xConnect", TCL_GLOBAL_ONLY);
  for(i=0; i<argc; i++){
    Tcl_SetVar(interp, "echo_module", argv[i],
                TCL_APPEND_VALUE | TCL_LIST_ELEMENT | TCL_GLOBAL_ONLY);
  }

  echoDeclareVtab(db, argc, argv);
  return 0;
}
static int echoDisconnect(sqlite3_vtab *pVtab){
  Tcl_Interp *interp = (Tcl_Interp*)pVtab;
  Tcl_SetVar(interp, "echo_module", "xDisconnect",
                TCL_APPEND_VALUE | TCL_LIST_ELEMENT | TCL_GLOBAL_ONLY);
  return 0;

*************************************************************************
** An tokenizer for SQL
**
** This file contains C code that splits an SQL input string up into
** individual tokens and sends those tokens one-by-one over to the
** parser for analysis.
**
** $Id: tokenize.c,v 1.119 2006/06/11 23:41:56 drh Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include <stdlib.h>

/*
................................................................................
#ifndef SQLITE_OMIT_SHARED_CACHE
  if( pParse->nested==0 ){
    sqliteFree(pParse->aTableLock);
    pParse->aTableLock = 0;
    pParse->nTableLock = 0;
  }
#endif

#ifndef SQLITE_OMIT_VIRTUALTABLE
  sqliteFree(pParse->zArg);
#endif






  sqlite3DeleteTable(pParse->db, pParse->pNewTable);


  sqlite3DeleteTrigger(pParse->pNewTrigger);
  sqliteFree(pParse->apVarExpr);
  if( nErr>0 && (pParse->rc==SQLITE_OK || pParse->rc==SQLITE_DONE) ){
    pParse->rc = SQLITE_ERROR;
  }
  return nErr;
}

*************************************************************************
** An tokenizer for SQL
**
** This file contains C code that splits an SQL input string up into
** individual tokens and sends those tokens one-by-one over to the
** parser for analysis.
**
** $Id: tokenize.c,v 1.120 2006/06/12 11:24:37 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include <ctype.h>
#include <stdlib.h>

/*
................................................................................
#ifndef SQLITE_OMIT_SHARED_CACHE
  if( pParse->nested==0 ){
    sqliteFree(pParse->aTableLock);
    pParse->aTableLock = 0;
    pParse->nTableLock = 0;
  }
#endif

#ifndef SQLITE_OMIT_VIRTUALTABLE
  sqliteFree(pParse->zArg);
#endif

  if( !IN_DECLARE_VTAB ){
    /* If the pParse->declareVtab flag is set, do not delete any table 
    ** structure built up in pParse->pNewTable. The calling code (see vtab.c)
    ** will take responsibility for freeing the Table structure.
    */
    sqlite3DeleteTable(pParse->db, pParse->pNewTable);
  }

  sqlite3DeleteTrigger(pParse->pNewTrigger);
  sqliteFree(pParse->apVarExpr);
  if( nErr>0 && (pParse->rc==SQLITE_OK || pParse->rc==SQLITE_DONE) ){
    pParse->rc = SQLITE_ERROR;
  }
  return nErr;
}

**    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 help implement virtual tables.
**
** $Id: vtab.c,v 1.2 2006/06/12 06:09:19 danielk1977 Exp $
*/
#ifndef SQLITE_OMIT_VIRTUALTABLE
#include "sqliteInt.h"

/*
** External API function used to create a new virtual-table module.
*/
................................................................................
  pParse->nArgAlloc = 0;

  /* Lookup the module name. */
  pTab = pParse->pNewTable;
  if( pTab==0 ) return;
  db = pParse->db;
  if( pTab->nModuleArg<1 ) return;
  pParse->pNewTable = 0;
  zModule = pTab->azModuleArg[0];
  pTab->pModule = (sqlite3_module*)sqlite3HashFind(&db->aModule, 
                     zModule, strlen(zModule));
  
  /* If the CREATE VIRTUAL TABLE statement is being entered for the
  ** first time (in other words if the virtual table is actually being
  ** created now instead of just being read out of sqlite_master) then
................................................................................
  }

  /* If we are rereading the sqlite_master table create the in-memory
  ** record of the table. 
  **
  ** TODO: If the module is already registered, should we call xConnect()
  ** here, or should it wait until the table is first referenced. Maybe
  ** it's better to be lazy here, in case xConnect() is expensive to call.

  */
  else {
#if 0
    sqlite3_module *pMod = pTab->pModule;
    assert( pMod->xConnect );
    pMod->xConnect(db, pMod, pTab->nModuleArg, pTab->azModuleArg, &pTab->pVtab);
#endif
    Table *pOld;
    Schema *pSchema = pTab->pSchema;
    const char *zName = pTab->zName;
    int nName = strlen(zName) + 1;
    pOld = sqlite3HashInsert(&pSchema->tblHash, zName, nName, pTab);
    if( pOld ){
      assert( pTab==pOld );  /* Malloc must have failed inside HashInsert() */
      return;
    }

  }
}

/*
** The parser calls this routine when it sees the first token
** of an argument to the module name in a CREATE VIRTUAL TABLE statement.
*/
................................................................................
  if( pParse->nArgUsed ){
    pParse->zArg[pParse->nArgUsed++] = ' ';
  }
  memcpy(&pParse->zArg[pParse->nArgUsed], p->z, p->n);
  pParse->nArgUsed += p->n;
  pParse->zArg[pParse->nArgUsed] = 0;
}















































































/*
** This function is invoked by the vdbe to call the xCreate method
** of the virtual table named zTab in database iDb. 
**
** If an error occurs, *pzErr is set to point an an English language
** description of the error and an SQLITE_XXX error code is returned.
** In this case the caller must call sqliteFree() on *pzErr.
*/
int sqlite3VtabCallCreate(sqlite3 *db, int iDb, const char *zTab, char **pzErr){
  int rc = SQLITE_OK;
  Table *pTab;
  sqlite3_module *pModule;


  pTab = sqlite3FindTable(db, zTab, db->aDb[iDb].zName);
  assert(pTab && pTab->isVirtual);
  pModule = pTab->pModule;
  const char *zModule = pTab->azModuleArg[0];

  /* If the module has been registered and includes a Create method, 
  ** invoke it now. If the module has not been registered, return an 
  ** error. Otherwise, do nothing.
  */
  if( !pModule ){
    *pzErr = sqlite3MPrintf("unknown module: %s", zModule);
    rc = SQLITE_ERROR;
  }else if( pModule->xCreate ){
    /* TODO: Maybe the above condition should refer to pTable->needCreate. */
    char **azArg = pTab->azModuleArg;
    int nArg = pTab->nModuleArg;




    rc = pModule->xCreate(db, pModule, nArg, azArg, &pTab->pVtab);







  }

  if( SQLITE_OK==rc ){
    pTab->needCreate = 0;
  }
  return rc;
}

#endif /* SQLITE_OMIT_VIRTUALTABLE */

**    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 help implement virtual tables.
**
** $Id: vtab.c,v 1.3 2006/06/12 11:24:37 danielk1977 Exp $
*/
#ifndef SQLITE_OMIT_VIRTUALTABLE
#include "sqliteInt.h"

/*
** External API function used to create a new virtual-table module.
*/
................................................................................
  pParse->nArgAlloc = 0;

  /* Lookup the module name. */
  pTab = pParse->pNewTable;
  if( pTab==0 ) return;
  db = pParse->db;
  if( pTab->nModuleArg<1 ) return;

  zModule = pTab->azModuleArg[0];
  pTab->pModule = (sqlite3_module*)sqlite3HashFind(&db->aModule, 
                     zModule, strlen(zModule));
  
  /* If the CREATE VIRTUAL TABLE statement is being entered for the
  ** first time (in other words if the virtual table is actually being
  ** created now instead of just being read out of sqlite_master) then
................................................................................
  }

  /* If we are rereading the sqlite_master table create the in-memory
  ** record of the table. 
  **
  ** TODO: If the module is already registered, should we call xConnect()
  ** here, or should it wait until the table is first referenced. Maybe
  ** it's better to be lazy here, in case xConnect() is expensive to call
  ** and the schema is reparsed a number of times.
  */
  else {





    Table *pOld;
    Schema *pSchema = pTab->pSchema;
    const char *zName = pTab->zName;
    int nName = strlen(zName) + 1;
    pOld = sqlite3HashInsert(&pSchema->tblHash, zName, nName, pTab);
    if( pOld ){
      assert( pTab==pOld );  /* Malloc must have failed inside HashInsert() */
      return;
    }
    pParse->pNewTable = 0;
  }
}

/*
** The parser calls this routine when it sees the first token
** of an argument to the module name in a CREATE VIRTUAL TABLE statement.
*/
................................................................................
  if( pParse->nArgUsed ){
    pParse->zArg[pParse->nArgUsed++] = ' ';
  }
  memcpy(&pParse->zArg[pParse->nArgUsed], p->z, p->n);
  pParse->nArgUsed += p->n;
  pParse->zArg[pParse->nArgUsed] = 0;
}

/*
** This function is invoked by the parser to call the xConnect() method
** of table pTab. If an error occurs, an error code is returned and an error
** left in pParse.
*/
int sqlite3VtabCallConnect(Parse *pParse, Table *pTab){
  sqlite3_module *pModule;
  const char *zModule;
  int rc = SQLITE_OK;

  assert(pTab && pTab->isVirtual);
  if( pTab->pVtab ){
    return SQLITE_OK;
  }

  pModule = pTab->pModule;
  zModule = pTab->azModuleArg[0];
  if( !pModule || !pModule->xConnect ){
    const char *zModule = pTab->azModuleArg[0];
    sqlite3ErrorMsg(pParse, "unknown module: %s", zModule);
    rc = SQLITE_ERROR;
  } else {
    char **azArg = pTab->azModuleArg;
    int nArg = pTab->nModuleArg;
    assert( !pParse->db->pVTab );
    pParse->db->pVTab = pTab;
    rc = pModule->xConnect(pParse->db, pModule, nArg, azArg, &pTab->pVtab);
    pParse->db->pVTab = 0;
    if( rc ){
      sqlite3ErrorMsg(pParse, "module connect failed: %s", zModule);
    }
  }

  return rc;
}

int sqlite3_declare_vtab(sqlite3 *db, const char *zCreateTable){
  Parse sParse;

  int rc = SQLITE_OK;
  Table *pTab = db->pVTab;
  char *zErr = 0;

  if( !pTab ){
    sqlite3Error(db, SQLITE_MISUSE, 0);
    return SQLITE_MISUSE;
  }
  assert(pTab->isVirtual && pTab->nCol==0 && pTab->aCol==0);

  memset(&sParse, 0, sizeof(Parse));
  sParse.declareVtab = 1;
  sParse.db = db;

  if( 
      SQLITE_OK == sqlite3RunParser(&sParse, zCreateTable, &zErr) && 
      sParse.pNewTable && 
      !sParse.pNewTable->pSelect && 
      !sParse.pNewTable->isVirtual 
  ){
    pTab->aCol = sParse.pNewTable->aCol;
    pTab->nCol = sParse.pNewTable->nCol;
    sParse.pNewTable->nCol = 0;
    sParse.pNewTable->aCol = 0;
  } else {
    sqlite3Error(db, SQLITE_ERROR, zErr);
    sqliteFree(zErr);
    rc = SQLITE_ERROR;
  }
  sParse.declareVtab = 0;

  sqlite3_finalize((sqlite3_stmt*)sParse.pVdbe);
  sqlite3DeleteTable(0, sParse.pNewTable);
  sParse.pNewTable = 0;
  db->pVTab = 0;

  return rc;
}

/*
** This function is invoked by the vdbe to call the xCreate method
** of the virtual table named zTab in database iDb. 
**
** If an error occurs, *pzErr is set to point an an English language
** description of the error and an SQLITE_XXX error code is returned.
** In this case the caller must call sqliteFree() on *pzErr.
*/
int sqlite3VtabCallCreate(sqlite3 *db, int iDb, const char *zTab, char **pzErr){
  int rc = SQLITE_OK;
  Table *pTab;
  sqlite3_module *pModule;
  const char *zModule;

  pTab = sqlite3FindTable(db, zTab, db->aDb[iDb].zName);
  assert(pTab && pTab->isVirtual && !pTab->pVtab);
  pModule = pTab->pModule;
  zModule = pTab->azModuleArg[0];

  /* If the module has been registered and includes a Create method, 
  ** invoke it now. If the module has not been registered, return an 
  ** error. Otherwise, do nothing.
  */
  if( !pModule ){
    *pzErr = sqlite3MPrintf("unknown module: %s", zModule);
    rc = SQLITE_ERROR;
  }else if( pModule->xCreate ){

    char **azArg = pTab->azModuleArg;
    int nArg = pTab->nModuleArg;
    assert( !db->pVTab );
    db->pVTab = pTab;
    rc = sqlite3SafetyOff(db);
    assert( rc==SQLITE_OK );
    rc = pModule->xCreate(db, pModule, nArg, azArg, &pTab->pVtab);
    db->pVTab = 0;
    if( rc ){
      *pzErr = sqlite3MPrintf("module create failed: %s", zModule);
      sqlite3SafetyOn(db);
    } else {
      rc = sqlite3SafetyOn(db);
    }
  }

  if( SQLITE_OK==rc ){
    pTab->needCreate = 0;
  }
  return rc;
}

#endif /* SQLITE_OMIT_VIRTUALTABLE */

#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is creating and dropping virtual tables.
#
# $Id: vtab1.test,v 1.2 2006/06/12 06:09:19 danielk1977 Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# We cannot create a virtual table if the module has not
# been registered.
#
................................................................................
  set echo_module
} {xCreate echo}
do_test vtab1-1.5 {
  execsql {
    SELECT name, sql FROM sqlite_master ORDER BY 1
  }
} {t1 {CREATE VIRTUAL TABLE t1 USING echo}}



























finish_test

#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is creating and dropping virtual tables.
#
# $Id: vtab1.test,v 1.3 2006/06/12 11:24:38 danielk1977 Exp $

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# We cannot create a virtual table if the module has not
# been registered.
#
................................................................................
  set echo_module
} {xCreate echo}
do_test vtab1-1.5 {
  execsql {
    SELECT name, sql FROM sqlite_master ORDER BY 1
  }
} {t1 {CREATE VIRTUAL TABLE t1 USING echo}}

# If a single argument is passed to the echo module during table
# creation, it is assumed to be the name of a table in the same
# database. The echo module attempts to set the schema of the
# new virtual table to be the same as the existing database table.
#
do_test vtab1-2.1 {
  execsql {
    CREATE TABLE template(a, b, c);
  }
  execsql { PRAGMA table_info(template); }
} [list         \
  0 a {} 0 {} 0 \
  1 b {} 0 {} 0 \
  2 c {} 0 {} 0 \
]
do_test vtab1-2.2 {
  execsql {
    CREATE VIRTUAL TABLE t2 USING echo(template);
  }
  execsql { PRAGMA table_info(t2); }
} [list         \
  0 a {} 0 {} 0 \
  1 b {} 0 {} 0 \
  2 c {} 0 {} 0 \
]

finish_test