SQLite

**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*************************************************************************
** This file contains C code routines that are called by the parser
** when syntax rules are reduced.
**
** $Id: build.c,v 1.12 2000/06/02 01:17:37 drh Exp $
*/
#include "sqliteInt.h"

/*
** This routine is called after a single SQL statement has been
** parsed and we want to execute the code to implement 
** the statement.  Prior action routines should have already

    pParse->pNewTable = 0;
  }

  /* If not initializing, then create the table on disk.
  */
  if( !pParse->initFlag ){
    static VdbeOp addTable[] = {
      { OP_Open,        0, 1, MASTER_NAME },
      { OP_New,         0, 0, 0},
      { OP_String,      0, 0, "table"     },
      { OP_String,      0, 0, 0},            /* 3 */
      { OP_String,      0, 0, 0},            /* 4 */
      { OP_String,      0, 0, 0},            /* 5 */
      { OP_MakeRecord,  4, 0, 0},
      { OP_Put,         0, 0, 0},

  /* Generate code to remove the table and its reference in sys_master */
  v = pParse->pVdbe;
  if( v==0 ){
    v = pParse->pVdbe = sqliteVdbeCreate(pParse->db->pBe);
  }
  if( v ){
    static VdbeOp dropTable[] = {
      { OP_Open,       0, 1,        MASTER_NAME },
      { OP_ListOpen,   0, 0,        0},
      { OP_String,     0, 0,        0}, /* 2 */
      { OP_Next,       0, ADDR(10), 0}, /* 3 */
      { OP_Dup,        0, 0,        0},
      { OP_Field,      0, 2,        0},
      { OP_Ne,         0, ADDR(3),  0},
      { OP_Key,        0, 0,        0},

  ** command.  The initFlag is 1 when a database is opened and 
  ** CREATE INDEX statements are read out of the master table.  In
  ** the latter case the index already exists on disk, which is why
  ** we don't want to recreate it.
  */
  if( pParse->initFlag==0 ){
    static VdbeOp addTable[] = {
      { OP_Open,        0, 1, MASTER_NAME},
      { OP_New,         0, 0, 0},
      { OP_String,      0, 0, "index"},
      { OP_String,      0, 0, 0},  /* 3 */
      { OP_String,      0, 0, 0},  /* 4 */
      { OP_String,      0, 0, 0},  /* 5 */
      { OP_MakeRecord,  4, 0, 0},
      { OP_Put,         0, 0, 0},

      n = (int)pEnd->z - (int)pStart->z + 1;
      base = sqliteVdbeAddOpList(v, ArraySize(addTable), addTable);
      sqliteVdbeChangeP3(v, base+3, pIndex->zName, 0);
      sqliteVdbeChangeP3(v, base+4, pTab->zName, 0);
      sqliteVdbeChangeP3(v, base+5, pStart->z, n);
    }
    sqliteVdbeAddOp(v, OP_Open, 0, 0, pTab->zName, 0);
    sqliteVdbeAddOp(v, OP_Open, 1, 1, pIndex->zName, 0);
    lbl1 = sqliteVdbeMakeLabel(v);
    lbl2 = sqliteVdbeMakeLabel(v);
    sqliteVdbeAddOp(v, OP_Next, 0, lbl2, 0, lbl1);
    sqliteVdbeAddOp(v, OP_Key, 0, 0, 0, 0);
    for(i=0; i<pIndex->nField; i++){
      sqliteVdbeAddOp(v, OP_Field, 0, pIndex->aiField[i], 0, 0);
    }

    return;
  }

  /* Generate code to remove the index and from the master table */
  v = pParse->pVdbe = sqliteVdbeCreate(pParse->db->pBe);
  if( v ){
    static VdbeOp dropIndex[] = {
      { OP_Open,       0, 1,       MASTER_NAME},
      { OP_ListOpen,   0, 0,       0},
      { OP_String,     0, 0,       0}, /* 2 */
      { OP_Next,       0, ADDR(9), 0}, /* 3 */
      { OP_Dup,        0, 0,       0},
      { OP_Field,      0, 1,       0},
      { OP_Ne,         0, ADDR(3), 0},
      { OP_Key,        0, 0,       0},

    goto copy_cleanup;
  }
  v = pParse->pVdbe = sqliteVdbeCreate(pParse->db->pBe);
  if( v ){
    addr = sqliteVdbeAddOp(v, OP_FileOpen, 0, 0, 0, 0);
    sqliteVdbeChangeP3(v, addr, pFilename->z, pFilename->n);
    sqliteVdbeDequoteP3(v, addr);
    sqliteVdbeAddOp(v, OP_Open, 0, 1, pTab->zName, 0);
    for(i=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
      sqliteVdbeAddOp(v, OP_Open, i, 1, pIdx->zName, 0);
    }
    end = sqliteVdbeMakeLabel(v);
    addr = sqliteVdbeAddOp(v, OP_FileRead, pTab->nCol, end, 0, 0);
    if( pDelimiter ){
      sqliteVdbeChangeP3(v, addr, pDelimiter->z, pDelimiter->n);
      sqliteVdbeDequoteP3(v, addr);
    }else{

** sqlite and the code that does the actually reading and writing
** of information to the disk.
**
** This file uses GDBM as the database backend.  It should be
** relatively simple to convert to a different database such
** as NDBM, SDBM, or BerkeleyDB.
**
** $Id: dbbe.c,v 1.7 2000/06/02 01:17:37 drh Exp $
*/
#include "sqliteInt.h"
#include <gdbm.h>
#include <sys/stat.h>
#include <unistd.h>
#include <ctype.h>
#include <time.h>

/*
** Each open database file is an instance of this structure.
*/
typedef struct BeFile BeFile;
struct BeFile {
  char *zName;            /* Name of the file */
  GDBM_FILE dbf;          /* The file itself */
  int nRef;               /* Number of references */
  int delOnClose;         /* Delete when closing */
  int writeable;          /* Opened for writing */
  BeFile *pNext, *pPrev;  /* Next and previous on list of open files */
};

/*
** The following are state variables for the RC4 algorithm.  We
** use RC4 as a random number generator.  Each call to RC4 gives
** a random 8-bit number.

/*
** This routine opens a new database.  For the current driver scheme,
** the database name is the name of the directory
** containing all the files of the database.
*/
Dbbe *sqliteDbbeOpen(
  const char *zName,     /* The name of the database */
  int writeFlag,         /* True if we will be writing to the database */
  int createFlag,        /* True to create database if it doesn't exist */
  char **pzErrMsg        /* Write error messages (if any) here */
){
  Dbbe *pNew;
  struct stat statbuf;
  char *zMaster;

  if( !writeFlag ) createFlag = 0;
  if( stat(zName, &statbuf)!=0 ){
    if( createFlag ) mkdir(zName, 0750);
    if( stat(zName, &statbuf)!=0 ){
      sqliteSetString(pzErrMsg, "can't find or make directory \"", 
         zName, "\"", 0);
      return 0;
    }
  }
  if( !S_ISDIR(statbuf.st_mode) ){
    sqliteSetString(pzErrMsg, "not a directory: \"", zName, "\"", 0);
    return 0;
  }
  if( access(zName, writeFlag ? (X_OK|W_OK|R_OK) : (X_OK|R_OK)) ){
    sqliteSetString(pzErrMsg, "access permission denied", 0);
    return 0;
  }
  zMaster = 0;
  sqliteSetString(&zMaster, zName, "/" MASTER_NAME, 0);
  if( stat(zMaster, &statbuf)==0
   && access(zMaster, writeFlag ? (W_OK|R_OK) : R_OK)!=0 ){
    sqliteSetString(pzErrMsg, "access permission denied for ", zMaster, 0);
    sqliteFree(zMaster);
    return 0;
  }
  sqliteFree(zMaster);
  pNew = sqliteMalloc(sizeof(Dbbe) + strlen(zName) + 1);
  if( pNew==0 ){
    sqliteSetString(pzErrMsg, "out of memory", 0);
    return 0;
  }
  pNew->zDir = (char*)&pNew[1];
  strcpy(pNew->zDir, zName);
  pNew->write = writeFlag;
  pNew->pOpen = 0;
  time(&statbuf.st_ctime);
  rc4init(&pNew->rc4, (char*)&statbuf, sizeof(statbuf));
  return pNew;
}

/*

  zBuf[j] = 0;
}


/*
** Open a new table cursor
*/
int sqliteDbbeOpenTable(
  Dbbe *pBe,              /* The database the table belongs to */
  const char *zTable,     /* The name of the table */
  int writeable,          /* True to open for writing */
  DbbeTable **ppTable     /* Write the resulting table pointer here */
){
  char *zFile;            /* Name of the table file */
  DbbeTable *pTable;      /* The new table cursor */
  BeFile *pFile;          /* The underlying data file for this table */
  int rc = SQLITE_OK;     /* Return value */
  int rw_mask;            /* Permissions mask for opening a table */
  int mode;               /* Mode for opening a table */

  *ppTable = 0;
  pTable = sqliteMalloc( sizeof(*pTable) );
  if( pTable==0 ) return SQLITE_NOMEM;
  if( zTable ){
    zFile = sqliteFileOfTable(pBe, zTable);
    for(pFile=pBe->pOpen; pFile; pFile=pFile->pNext){
      if( strcmp(pFile->zName,zFile)==0 ) break;
    }
  }else{
    pFile = 0;
    zFile = 0;
  }
  if( pFile==0 ){
    if( writeable ){
      rw_mask = GDBM_WRCREAT | GDBM_FAST;
      mode = 0640;
    }else{
      rw_mask = GDBM_READER;
      mode = 0640;
    }
    pFile = sqliteMalloc( sizeof(*pFile) );
    if( pFile==0 ){
      sqliteFree(zFile);
      return SQLITE_NOMEM;
    }








    if( pFile->zName ){
      pFile->dbf = gdbm_open(pFile->zName, 0, rw_mask, mode, 0);
    }else{
      int limit;
      struct rc4 *pRc4;
      char zRandom[50];
      pRc4 = &pBe->rc4;
      zFile = 0;
      limit = 5;
      do {
        randomName(&pBe->rc4, zRandom, "_temp_table_");
        sqliteFree(zFile);
        zFile = sqliteFileOfTable(pBe, zRandom);
        pFile->dbf = gdbm_open(zFile, 0, rw_mask, mode, 0);
      }while( pFile->dbf==0 && limit-- >= 0);
      pFile->delOnClose = 1;
    }
    pFile->writeable = writeable;
    pFile->zName = zFile;
    pFile->nRef = 1;
    pFile->pPrev = 0;
    if( pBe->pOpen ){
      pBe->pOpen->pPrev = pFile;
    }
    pFile->pNext = pBe->pOpen;
    pBe->pOpen = pFile;
    if( pFile->dbf==0 ){
      rc = SQLITE_BUSY;
    }
  }else{
    sqliteFree(zFile);
    pFile->nRef++;
    if( writeable && !pFile->writeable ){
      rc = SQLITE_READONLY;
    }
  }
  pTable->pBe = pBe;
  pTable->pFile = pFile;
  pTable->readPending = 0;
  pTable->needRewind = 1;
  *ppTable = pTable;
  return rc;
}

/*
** Drop a table from the database.
*/
void sqliteDbbeDropTable(Dbbe *pBe, const char *zTable){
  char *zFile;            /* Name of the table file */

  zFile = sqliteFileOfTable(pBe, zTable);
  unlink(zFile);
  sqliteFree(zFile);
}

/*
** Reorganize a table to reduce search times and disk usage.
*/
void sqliteDbbeReorganizeTable(Dbbe *pBe, const char *zTable){
  char *zFile;            /* Name of the table file */
  DbbeTable *pTab;

  if( sqliteDbbeOpenTable(pBe, zTable, 1, &pTab)!=SQLITE_OK ){
    return;
  }
  if( pTab && pTab->pFile && pTab->pFile->dbf ){
    gdbm_reorganize(pTab->pFile->dbf);
  }
  if( pTab ){
    sqliteDbbeCloseTable(pTab);
  }
}

/*
** Make is so that the next call to sqliteNextKey() finds the first
** key of the table.
*/
int sqliteDbbeRewind(DbbeTable *pTable){
  pTable->needRewind = 1;
  return SQLITE_OK;
}

/*
** Read the next key from the table.  Return 1 on success.  Return
** 0 if there are no more keys.
*/
int sqliteDbbeNextKey(DbbeTable *pTable){

/*
** Write an entry into the table.  Overwrite any prior entry with the
** same key.
*/
int sqliteDbbePut(DbbeTable *pTable, int nKey,char *pKey,int nData,char *pData){
  datum data, key;
  int rc;
  if( pTable->pFile==0 || pTable->pFile->dbf==0 ) return SQLITE_ERROR;
  data.dsize = nData;
  data.dptr = pData;
  key.dsize = nKey;
  key.dptr = pKey;
  rc = gdbm_store(pTable->pFile->dbf, key, data, GDBM_REPLACE);
  if( rc ) rc = SQLITE_ERROR;
  datumClear(&pTable->key);
  datumClear(&pTable->data);
  return rc;
}

/*
** Remove an entry from a table, if the entry exists.
*/
int sqliteDbbeDelete(DbbeTable *pTable, int nKey, char *pKey){
  datum key;
  int rc;
  datumClear(&pTable->key);
  datumClear(&pTable->data);
  if( pTable->pFile==0 || pTable->pFile->dbf==0 ) return SQLITE_ERROR;
  key.dsize = nKey;
  key.dptr = pKey;
  rc = gdbm_delete(pTable->pFile->dbf, key);
  if( rc ) rc = SQLITE_ERROR;
  return rc;
}

/*
** Open a temporary file.
*/
int sqliteDbbeOpenTempFile(Dbbe *pBe, FILE **ppFile){
  char *zFile;
  char zBuf[50];
  int i, j;
  int limit;
  int rc = SQLITE_OK;

  for(i=0; i<pBe->nTemp; i++){
    if( pBe->apTemp[i]==0 ) break;
  }
  if( i>=pBe->nTemp ){
    pBe->nTemp++;
    pBe->apTemp = sqliteRealloc(pBe->apTemp, pBe->nTemp*sizeof(FILE*) );
  }
  if( pBe->apTemp==0 ){
    *ppFile = 0;
    return SQLITE_NOMEM;
  }
  limit = 4;
  zFile = 0;
  do{
    randomName(&pBe->rc4, zBuf, "/_temp_file_");
    sqliteFree(zFile);
    zFile = 0;
    sqliteSetString(&zFile, pBe->zDir, zBuf, 0);
  }while( access(zFile,0)==0 && limit-- >= 0 );
  *ppFile = pBe->apTemp[i] = fopen(zFile, "w+");
  if( pBe->apTemp[i]==0 ){
    rc = SQLITE_ERROR;
  }
  sqliteFree(zFile);
  return rc;
}

/*
** Close a temporary file opened using sqliteDbbeOpenTempFile()
*/
void sqliteDbbeCloseTempFile(Dbbe *pBe, FILE *f){
  int i;

** This file defines the interface to the database backend (Dbbe).
**
** The database backend is designed to be as general as possible
** so that it can easily be replaced by a different backend.
** This library was originally designed to support the following
** backends: GDBM, NDBM, SDBM, Berkeley DB.
**
** $Id: dbbe.h,v 1.4 2000/06/02 01:17:37 drh Exp $
*/
#ifndef _SQLITE_DBBE_H_
#define _SQLITE_DBBE_H_
#include <stdio.h>

/*
** The database backend supports two opaque structures.  A Dbbe is

/* Open a particular table of a previously opened database.
** Create the table if it doesn't already exist and writeable!=0.
**
** If zTableName is 0 or "", then a temporary table is created that
** will be deleted when closed.
*/
int sqliteDbbeOpenTable(Dbbe*, const char *zName, int writeable, DbbeTable **);

/* Delete a table from the database */
void sqliteDbbeDropTable(Dbbe*, const char *zTableName);

/* Reorganize a table to speed access or reduce its disk usage */
void sqliteDbbeReorganizeTable(Dbbe*, const char *zTableName);

*/
int sqliteDbbePut(DbbeTable*, int nKey, char *pKey, int nData, char *pData);

/* Remove an entry from the table */
int sqliteDbbeDelete(DbbeTable*, int nKey, char *pKey);

/* Open a file suitable for temporary storage */
int sqliteDbbeOpenTempFile(Dbbe*, FILE**);

/* Close a temporary file */
void sqliteDbbeCloseTempFile(Dbbe *, FILE *);

#endif /* defined(_SQLITE_DBBE_H_) */

**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle DELETE FROM statements.
**
** $Id: delete.c,v 1.2 2000/06/02 01:17:37 drh Exp $
*/
#include "sqliteInt.h"

/*
** Process a DELETE FROM statement.
*/
void sqliteDeleteFrom(

  /* End the database scan loop.
  */
  sqliteWhereEnd(pWInfo);

  /* Delete every item identified in the list.
  */
  sqliteVdbeAddOp(v, OP_ListRewind, 0, 0, 0, 0);
  sqliteVdbeAddOp(v, OP_Open, 0, 1, pTab->zName, 0);
  for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
    sqliteVdbeAddOp(v, OP_Open, i, 1, pIdx->zName, 0);
  }
  end = sqliteVdbeMakeLabel(v);
  addr = sqliteVdbeAddOp(v, OP_ListRead, 0, end, 0, 0);
  if( pTab->pIndex ){
    sqliteVdbeAddOp(v, OP_Dup, 0, 0, 0, 0);
    sqliteVdbeAddOp(v, OP_Fetch, 0, 0, 0, 0);
    for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){

**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle INSERT statements.
**
** $Id: insert.c,v 1.2 2000/06/02 01:17:37 drh Exp $
*/
#include "sqliteInt.h"

/*
** This routine is call to handle SQL of the following form:
**
**    insert into TABLE (IDLIST) values(EXPRLIST)

        goto insert_cleanup;
      }
    }
  }
  v = pParse->pVdbe = sqliteVdbeCreate(pParse->db->pBe);
  if( v ){
    Index *pIdx;
    sqliteVdbeAddOp(v, OP_Open, 0, 1, pTab->zName, 0);
    sqliteVdbeAddOp(v, OP_New, 0, 0, 0, 0);
    if( pTab->pIndex ){
      sqliteVdbeAddOp(v, OP_Dup, 0, 0, 0, 0);
    }
    for(i=0; i<pTab->nCol; i++){
      if( pField==0 ){
        j = i;

    sqliteVdbeAddOp(v, OP_MakeRecord, pTab->nCol, 0, 0, 0);
    sqliteVdbeAddOp(v, OP_Put, 0, 0, 0, 0);
    sqliteVdbeAddOp(v, OP_Close, 0, 0, 0, 0);
    for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
      if( pIdx->pNext ){
        sqliteVdbeAddOp(v, OP_Dup, 0, 0, 0, 0);
      }
      sqliteVdbeAddOp(v, OP_Open, 0, 1, pIdx->zName, 0);
      for(i=0; i<pIdx->nField; i++){
        int idx = pIdx->aiField[i];
        if( pField==0 ){
          j = idx;
        }else{
          for(j=0; j<pField->nId; j++){
            if( pField->a[j].idx==idx ) break;

**
*************************************************************************
** 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 1.3 2000/06/02 01:17:37 drh Exp $
*/
#include "sqliteInt.h"

/*
** This is the callback routine for the code that initializes the
** database.  Each callback contains text of a CREATE TABLE or
** CREATE INDEX statement that must be parsed to yield the internal

  sParse.db = db;
  sParse.initFlag = 1;
  nErr = sqliteRunParser(&sParse, argv[0], &zErrMsg);
  return nErr;
}

/*
** Attempt to read the database schema and initialize internal
** data structures.  Return one of the SQLITE_ error codes to
** indicate success or failure.
*/
static int sqliteInit(sqlite *db, char **pzErrMsg){

  Vdbe *vdbe;
  int rc;

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

    { OP_Ne,       0, 9,  0},
    { OP_Field,    0, 3,  0},
    { OP_Callback, 1, 0,  0},
    { OP_Goto,     0, 9,  0},
    { OP_Halt,     0, 0,  0},           /* 16 */
  };

  /* Create a virtual machine to run the initialization program.  Run
  ** the program.  The delete the virtual machine.
  */
  vdbe = sqliteVdbeCreate(db->pBe);
  sqliteVdbeAddOpList(vdbe, sizeof(initProg)/sizeof(initProg[0]), initProg);
  rc = sqliteVdbeExec(vdbe, sqliteOpenCb, db, pzErrMsg);
  sqliteVdbeDelete(vdbe);
  if( rc==SQLITE_OK ){
    Table *pTab;
    char *azArg[2];
    azArg[0] = master_schema;
    azArg[1] = 0;
    sqliteOpenCb(db, 1, azArg, 0);
    pTab = sqliteFindTable(db, MASTER_NAME);
    if( pTab ){
      pTab->readOnly = 1;
    }
    db->flags |= SQLITE_Initialized;
  }else{
    sqliteStrRealloc(pzErrMsg);
  }
  return rc;
}

/*
** Open a new SQLite database.  Construct an "sqlite" structure to define
** the state of this database and return a pointer to that structure.
**
** An attempt is made to initialize the in-memory data structures that
** hold the database schema.  But if this fails (because the schema file
** is locked) then that step is deferred until the first call to
** sqlite_exec().
*/
sqlite *sqlite_open(const char *zFilename, int mode, char **pzErrMsg){
  sqlite *db;
  int rc;

  /* Allocate the sqlite data structure */
  db = sqliteMalloc( sizeof(sqlite) );
  if( pzErrMsg ) *pzErrMsg = 0;
  if( db==0 ){
    sqliteSetString(pzErrMsg, "out of memory", 0);
    sqliteStrRealloc(pzErrMsg);
    return 0;
  }
  
  /* Open the backend database driver */
  db->pBe = sqliteDbbeOpen(zFilename, (mode&0222)!=0, mode!=0, pzErrMsg);
  if( db->pBe==0 ){
    sqliteFree(db);
    return 0;
  }




  /* Attempt to read the schema */


  rc = sqliteInit(db, pzErrMsg);
  if( rc!=SQLITE_OK && rc!=SQLITE_BUSY ){
    sqlite_close(db);
    return 0;
  }




  return db;
}

/*
** Close an existing SQLite database
*/
void sqlite_close(sqlite *db){

  sqlite *db,                 /* The database on which the SQL executes */
  char *zSql,                 /* The SQL to be executed */
  sqlite_callback xCallback,  /* Invoke this callback routine */
  void *pArg,                 /* First argument to xCallback() */
  char **pzErrMsg             /* Write error messages here */
){
  Parse sParse;
  int rc;

  if( pzErrMsg ) *pzErrMsg = 0;
  if( (db->flags & SQLITE_Initialized)==0 ){
    int rc = sqliteInit(db, pzErrMsg);
    if( rc!=SQLITE_OK ) return rc;
  }
  memset(&sParse, 0, sizeof(sParse));
  sParse.db = db;
  sParse.xCallback = xCallback;
  sParse.pArg = pArg;
  rc = sqliteRunParser(&sParse, zSql, pzErrMsg);
  sqliteStrRealloc(pzErrMsg);
  return rc;
}

**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*************************************************************************
** This header file defines the interface that the sqlite library
** presents to client programs.
**
** @(#) $Id: sqlite.h,v 1.2 2000/06/02 01:17:38 drh Exp $
*/
#ifndef _SQLITE_H_
#define _SQLITE_H_

/*
** Each open sqlite database is represented by an instance of the
** following opaque structure.

** A function to executes one or more statements of SQL.
**
** If one or more of the SQL statements are queries, then
** the callback function specified by the 3rd parameter is
** invoked once for each row of the query result.  This callback
** should normally return 0.  If the callback returns a non-zero
** value then the query is aborted, all subsequent SQL statements
** are skipped and the sqlite_exec() function returns the SQLITE_ABORT.

**
** The 4th parameter is an arbitrary pointer that is passed
** to the callback function as its first parameter.
**
** The 2nd parameter to the callback function is the number of
** columns in the query result.  The 3rd parameter is an array
** of string holding the values for each column.  The 4th parameter
** is an array of strings holding the names of each column.
**
** The callback function may be NULL, even for queries.  A NULL
** callback is not an error.  It just means that no callback
** will be invoked.
**
** If an error occurs while parsing or evaluating the SQL (but
** not while executing the callback) then an appropriate error
** message is written into memory obtained from malloc() and
** *errmsg is made to point to that message.  If errmsg==NULL,
** then no error message is ever written.  The return value is
** SQLITE_ERROR if an error occurs.
**
** If the query could not be executed because a database file is
** locked or busy, then this function returns SQLITE_BUSY.  If
** the query could not be executed because a file is missing or
** has incorrect permissions, this function returns SQLITE_ERROR.
*/
int sqlite_exec(
  sqlite*,                      /* An open database */
  char *sql,                    /* SQL to be executed */
  sqlite_callback,              /* Callback function */
  void *,                       /* 1st argument to callback function */
  char **errmsg                 /* Error msg written here */
);

/*
** Return values fro sqlite_exec()
*/
#define SQLITE_OK        0    /* Successful result */
#define SQLITE_INTERNAL  1    /* An internal logic error in SQLite */
#define SQLITE_ERROR     2    /* SQL error or missing database */
#define SQLITE_ABORT     3    /* Callback routine requested an abort */
#define SQLITE_BUSY      4    /* One or more database files are locked */
#define SQLITE_NOMEM     5    /* A malloc() failed */


/* This function returns true if the given input string comprises
** one or more complete SQL statements.
**
** The algorithm is simple.  If the last token other than spaces
** and comments is a semicolon, then return true.  otherwise return
** false.
*/
int sqlite_complete(const char *sql);

#endif /* _SQLITE_H_ */

** Author contact information:
**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.8 2000/06/02 01:17:38 drh Exp $
*/
#include "sqlite.h"
#include "dbbe.h"
#include "vdbe.h"
#include "parse.h"
#include <gdbm.h>
#include <stdio.h>

  Index *apIdxHash[N_HASH];  /* All indices of the database */
};

/*
** Possible values for the flags field of sqlite
*/
#define SQLITE_VdbeTrace    0x00000001
#define SQLITE_Initialized  0x00000002

/*
** Values for SQLITE_OK, SQLITE_ERROR, etc are defined in sqlite.h.
** The following are several new return codes that are used internally
** only.  Take care that these values do not overlap.
*/
#define SQLITE_READONLY   6    /* Table already opened as read-only */

/*
** Each table is represented in memory by
** an instance of the following structure
*/
struct Table {
  char *zName;        /* Name of the table */

** Author contact information:
**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*************************************************************************
** A TCL Interface to SQLite
**
** $Id: tclsqlite.c,v 1.4 2000/06/02 01:17:38 drh Exp $
*/
#include "sqlite.h"
#include <tcl.h>
#include <stdlib.h>
#include <string.h>

/*

  char *zErrMsg;
  if( argc!=3 && argc!=4 ){
    Tcl_AppendResult(interp,"wrong # args: should be \"", argv[0],
       " HANDLE FILENAME ?MODE?\"", 0);
    return TCL_ERROR;
  }
  if( argc==3 ){
    mode = 0666;
  }else if( Tcl_GetInt(interp, argv[3], &mode)!=TCL_OK ){
    return TCL_ERROR;
  }
  zErrMsg = 0;
  p = sqlite_open(argv[2], mode, &zErrMsg);
  if( p==0 ){
    Tcl_SetResult(interp, zErrMsg, TCL_VOLATILE);

**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*************************************************************************
** This file contains C code routines that are called by the parser
** to handle UPDATE statements.
**
** $Id: update.c,v 1.2 2000/06/02 01:17:38 drh Exp $
*/
#include "sqliteInt.h"

/*
** Process an UPDATE statement.
*/
void sqliteUpdate(

  */
  sqliteWhereEnd(pWInfo);

  /* Rewind the list of records that need to be updated and
  ** open every index that needs updating.
  */
  sqliteVdbeAddOp(v, OP_ListRewind, 0, 0, 0, 0);
  sqliteVdbeAddOp(v, OP_Open, 0, 1, pTab->zName, 0);
  for(i=0; i<nIdx; i++){
    sqliteVdbeAddOp(v, OP_Open, i+1, 1, apIdx[i]->zName, 0);
  }

  /* Loop over every record that needs updating.  We have to load
  ** the old data for each record to be updated because some fields
  ** might not change and we will need to copy the old value, therefore.
  ** Also, the old data is needed to delete the old index entires.
  */

** inplicit conversion from one type to the other occurs as necessary.
** 
** Most of the code in this file is taken up by the sqliteVdbeExec()
** function which does the work of interpreting a VDBE program.
** But other routines are also provided to help in building up
** a program instruction by instruction.
**
** $Id: vdbe.c,v 1.7 2000/06/02 01:17:38 drh Exp $
*/
#include "sqliteInt.h"

/*
** SQL is translated into a sequence of instructions to be
** executed by a virtual machine.  Each instruction is an instance
** of the following structure.

  };

  if( xCallback==0 ) return 0;
  azField[0] = zAddr;
  azField[2] = zP1;
  azField[3] = zP2;
  azField[5] = 0;
  rc = SQLITE_OK;
  if( pzErrMsg ){ *pzErrMsg = 0; }
  for(i=0; rc==SQLITE_OK && i<p->nOp; i++){
    sprintf(zAddr,"%d",i);
    sprintf(zP1,"%d", p->aOp[i].p1);
    sprintf(zP2,"%d", p->aOp[i].p2);
    azField[4] = p->aOp[i].p3;
    if( azField[4]==0 ) azField[4] = "";
    azField[1] = zOpName[p->aOp[i].opcode];
    if( xCallback(pArg, 5, azField, azColumnNames) ){
      rc = SQLITE_ABORT;
    }
  }
  return rc;
}

/*
** Make sure space has been allocated to hold at least N
** stack elements.  Allocate additional stack space if

** Execute the program in the VDBE.
**
** If an error occurs, an error message is written to memory obtained
** from sqliteMalloc() and *pzErrMsg is made to point to that memory.
** The return parameter is the number of errors.
**
** If the callback every returns non-zero, then the program exits
** immediately.  No error message but the function does return SQLITE_ABORT.
**
** A memory allocation error causes this routine to return SQLITE_NOMEM
** and abandon furture processing.
**
** Other fatal errors return SQLITE_ERROR.
**
** If a database file could not be opened because it is locked by
** another database instance, then this routine returns SQLITE_BUSY.
*/
int sqliteVdbeExec(
  Vdbe *p,                   /* The VDBE */
  sqlite_callback xCallback, /* The callback */
  void *pArg,                /* 1st argument to callback */
  char **pzErrMsg            /* Error msg written here */
){
  int pc;                    /* The program counter */
  Op *pOp;                   /* Current operation */
  int rc;                    /* Value to return */
  char zBuf[100];            /* Space to sprintf() and integer */

  p->tos = -1;
  rc = SQLITE_OK;
  if( pzErrMsg ){ *pzErrMsg = 0; }
  for(pc=0; rc==SQLITE_OK && pc<p->nOp && pc>=0; pc++){
    pOp = &p->aOp[pc];
    if( p->trace ){
      fprintf(p->trace,"%4d %-12s %4d %4d %s\n",
        pc, zOpName[pOp->opcode], pOp->p1, pOp->p2,
           pOp->p3 ? pOp->p3 : "");
    }
    switch( pOp->opcode ){
      /* Opcode:  Goto P2 * *
      **
      ** An unconditional jump to address P2.
      ** The next instruction executed will be 
      ** the one at index P2 from the beginning of
      ** the program.
      */
      case OP_Goto: {
        pc = pOp->p2 - 1;





        break;
      }

      /* Opcode:  Halt * * *
      **
      ** Exit immediately.  All open DBs, Lists, Sorts, etc are closed
      ** automatically.

        int j;
        if( i<0 ) goto not_enough_stack;
        if( NeedStack(p, p->tos+2) ) goto no_mem;
        for(j=i; j<=p->tos; j++){
          if( Stringify(p, j) ) goto no_mem;
        }
        p->zStack[p->tos+1] = 0;
        if( xCallback(pArg, pOp->p1, &p->zStack[i], p->azColName)!=0 ){
          rc = SQLITE_ABORT;
        }
        PopStack(p, pOp->p1);
        break;
      }

      /* Opcode: Concat * * *
      **
      ** Pop two elements from the stack.  Append the first (what used

          switch( pOp->opcode ){
            case OP_Add:         b += a;       break;
            case OP_Subtract:    b -= a;       break;
            case OP_Multiply:    b *= a;       break;
            default: {
              if( a==0 ){ 
                sqliteSetString(pzErrMsg, "division by zero", 0);
                rc = SQLITE_ERROR;
                goto cleanup;
              }
              b /= a;
              break;
            }
          }
          PopStack(p, 1);

          switch( pOp->opcode ){
            case OP_Add:         b += a;       break;
            case OP_Subtract:    b -= a;       break;
            case OP_Multiply:    b *= a;       break;
            default: {
              if( a==0.0 ){ 
                sqliteSetString(pzErrMsg, "division by zero", 0);
                rc = SQLITE_ERROR;
                goto cleanup;
              }
              b /= a;
              break;
            }
          }
          sprintf(zBuf,"%g",b);

        NeedStack(p, p->tos+1);
        p->tos++;
        p->iStack[p->tos] = nByte;
        p->zStack[p->tos] = zNewKey;
        break;
      }

      /* Opcode: Open P1 P2 P3
      **
      ** Open a new database table named P3.  Give it an identifier P1.
      ** Open readonly if P2==0 and for reading and writing if P2!=0.
      ** The table is created if it does not already exist and P2!=0.
      ** If there is already another table opened on P1, then the old
      ** table is closed first.  All tables are automatically closed when
      ** the VDBE finishes execution.  The P1 values need not be

          p->aTab = sqliteRealloc( p->aTab, (i+1)*sizeof(VdbeTable) );
          if( p->aTab==0 ){ p->nTable = 0; goto no_mem; }
          for(j=p->nTable; j<=i; j++) p->aTab[j].pTable = 0;
          p->nTable = i+1;
        }else if( p->aTab[i].pTable ){
          sqliteDbbeCloseTable(p->aTab[i].pTable);
        }
        rc = sqliteDbbeOpenTable(p->pBe, pOp->p3, pOp->p2, &p->aTab[i].pTable);
        p->aTab[i].index = 0;
        break;
      }

      /* Opcode: Close P1 * *
      **
      ** Close a database table previously opened as P1.  If P1 is not

        int tos = p->tos;
        if( tos<0 ) goto not_enough_stack;
        if( i>=0 && i<p->nTable && p->aTab[i].pTable ){
          if( p->zStack[tos]==0 ){
            sqliteDbbeFetch(p->aTab[i].pTable, sizeof(int), 
                           (char*)&p->iStack[tos]);
          }else{
            sqliteDbbeFetch(p->aTab[i].pTable, p->iStack[tos], 
                           p->zStack[tos]);
          }
        }
        PopStack(p, 1);
        break;
      }

      /* Opcode: Distinct P1 P2 *

                                          (char*)&p->iStack[tos]);
          }else{
            alreadyExists = sqliteDbbeTest(p->aTab[i].pTable, p->iStack[tos], 
                                           p->zStack[tos]);
          }
        }
        if( !alreadyExists ){
          pc = pOp->p2 - 1;





        }
        break;
      }

      /* Opcode: New P1 * *
      **
      ** Get a new integer key not previous used by table P1 and

      ** Advance P1 to the next entry in the table.  Or, if there are no
      ** more entries, rewind P1 and jump to location P2.
      */
      case OP_Next: {
        int i = pOp->p1;
        if( i>=0 && i<p->nTable && p->aTab[i].pTable!=0 ){
          if( sqliteDbbeNextKey(p->aTab[i].pTable)==0 ){
            pc = pOp->p2 - 1;





          }
        }
        break;
      }

      /* Opcode: ResetIdx P1 * *
      **

            if( aIdx[j]!=0 ){
              p->iStack[tos] = aIdx[j];
              break;
            }
          }
          if( j>=nIdx ){
            j = -1;
            pc = pOp->p2 - 1;





            PopStack(p, 1);
          }
          p->aTab[i].index = j+1;
        }
        break;
      }

          p->apList = sqliteRealloc( p->apList, (i+1)*sizeof(FILE*) );
          if( p->apList==0 ){ p->nList = 0; goto no_mem; }
          for(j=p->nList; j<=i; j++) p->apList[j] = 0;
          p->nList = i+1;
        }else if( p->apList[i] ){
          sqliteDbbeCloseTempFile(p->pBe, p->apList[i]);
        }
        rc = sqliteDbbeOpenTempFile(p->pBe, &p->apList[i]);
        break;
      }

      /* Opcode: ListWrite P1 * *
      **
      ** Write the integer on the top of the stack
      ** into the temporary storage file P1.

        amt = fread(&val, sizeof(int), 1, p->apList[i]);
        if( amt==1 ){
          p->tos++;
          if( NeedStack(p, p->tos) ) goto no_mem;
          p->iStack[p->tos] = val;
          p->zStack[p->tos] = 0;
        }else{
          pc = pOp->p2 - 1;





        }
        break;
      }

      /* Opcode: ListClose P1 * *
      **
      ** Close the temporary storage buffer and discard its contents.

          p->tos++;
          NeedStack(p, p->tos);
          p->zStack[p->tos] = pSorter->pData;
          p->iStack[p->tos] = pSorter->nData;
          sqliteFree(pSorter->zKey);
          sqliteFree(pSorter);
        }else{
          pc = pOp->p2 - 1;





        }
        break;
      }

      /* Opcode: SortKey P1 * *
      **
      ** Push the key for the topmost element of the sorter onto the stack.

      ** the SortMakeRec operation with the same P1 value as this
      ** instruction.  Pop this record from the stack and invoke the
      ** callback on it.
      */
      case OP_SortCallback: {
        int i = p->tos;
        if( i<0 ) goto not_enough_stack;
        if( xCallback(pArg, pOp->p1, (char**)p->zStack[i], p->azColName) ){
          rc = SQLITE_ABORT;
        }
        PopStack(p, 1);
        break;
      }

      /* Opcode: SortClose P1 * *
      **
      ** Close the given sorter and remove all its elements.

        if( sqliteStrICmp(pOp->p3,"stdin")==0 ){
          p->pFile = stdin;
        }else{
          p->pFile = fopen(pOp->p3, "r");
        }
        if( p->pFile==0 ){
          sqliteSetString(pzErrMsg,"unable to open file: ", pOp->p3, 0);
          rc = SQLITE_ERROR;
          goto cleanup;
        }
        break;
      }

      /* Opcode: FileClose * * *
      **

          p->azField[i++] = "";
        }
        break;

        /* If we reach end-of-file, or if anything goes wrong, jump here.
        ** This code will cause a jump to P2 */
      fileread_jump:
        pc = pOp->p2 - 1;





        break;
      }

      /* Opcode: FileField P1 * *
      **
      ** Push onto the stack the P1-th field of the most recently read line
      ** from the file.

      }

      /* An other opcode is illegal...
      */
      default: {
        sprintf(zBuf,"%d",pOp->opcode);
        sqliteSetString(pzErrMsg, "unknown opcode ", zBuf, 0);
        rc = SQLITE_INTERNAL;
        break;
      }
    }
    if( pc<-1 || pc>=p->nOp ){
      sqliteSetString(pzErrMsg, "jump destination out of range", 0);
      rc = SQLITE_INTERNAL;
    }
    if( p->trace && p->tos>=0 ){
      int i;
      fprintf(p->trace, "Stack:");
      for(i=p->tos; i>=0 && i>p->tos-5; i--){
        if( p->zStack[i] ){
          fprintf(p->trace, " [%.11s]", p->zStack[i]);

  /* Jump to here if a operator is encountered that requires more stack
  ** operands than are currently available on the stack.
  */
not_enough_stack:
  sprintf(zBuf,"%d",pc);
  sqliteSetString(pzErrMsg, "too few operands on stack at ", zBuf, 0);
  rc = SQLITE_INTERNAL;
  goto cleanup;

  /* Jump here if an illegal or illformed instruction is executed.
  */
bad_instruction:
  sprintf(zBuf,"%d",pc);
  sqliteSetString(pzErrMsg, "illegal operation at ", zBuf, 0);
  rc = SQLITE_INTERNAL;
  goto cleanup;

}