SQLite

LIBREADLINE = @TARGET_READLINE_LIBS@

# Object files for the SQLite library.
#
LIBOBJ = build.o dbbe.o delete.o expr.o insert.o \
         main.o parse.o select.o tokenize.o update.o \
         util.o vdbe.o where.o

# All of the source code files.
#
SRC = \
  $(TOP)/src/build.c \
  $(TOP)/src/dbbe.c \
  $(TOP)/src/dbbe.h \
  $(TOP)/src/delete.c \
  $(TOP)/src/expr.c \
  $(TOP)/src/insert.c \
  $(TOP)/src/main.c \
  $(TOP)/src/parse.y \
  $(TOP)/src/select.c \
  $(TOP)/src/shell.c \
  $(TOP)/src/sqlite.h \
  $(TOP)/src/sqliteInt.h \
  $(TOP)/src/tclsqlite.c \
  $(TOP)/src/tokenize.c \
  $(TOP)/src/update.c \
  $(TOP)/src/util.c \
  $(TOP)/src/vdbe.c \
  $(TOP)/src/vdbe.h \
  $(TOP)/src/where.c

# This is the default Makefile target.  The objects listed here
# are what get build when you type just "make" with no arguments.
#
all:	libsqlite.a sqlite.h sqlite 

# Generate the file "last_change" which contains the date of change
# of the most recently modified source code file
#
last_change:	$(SRC)
	cat $(SRC) | grep '$$Id: ' | sort +4 | tail -1 \
          | awk '{print $$5,$$6}' >last_change

libsqlite.a:	$(LIBOBJ)
	$(AR) libsqlite.a $(LIBOBJ)
	$(RANLIB) libsqlite.a

sqlite:	$(TOP)/src/shell.c libsqlite.a sqlite.h
	$(TCC) $(READLINE_FLAGS) -o sqlite $(TOP)/src/shell.c \

sqlite.tar.gz:	
	pwd=`pwd`; cd $(TOP)/..; tar czf $$pwd/sqlite.tar.gz $(TARBALL)

all.tar.gz:	
	pwd=`pwd`; cd $(TOP)/..; tar czf $$pwd/all.tar.gz sqlite

index.html:	$(TOP)/www/index.tcl sqlite.tar.gz all.tar.gz last_change
	tclsh $(TOP)/www/index.tcl >index.html

sqlite.html:	$(TOP)/www/sqlite.tcl
	tclsh $(TOP)/www/sqlite.tcl >sqlite.html

c_interface.html:	$(TOP)/www/c_interface.tcl
	tclsh $(TOP)/www/c_interface.tcl >c_interface.html

This directory contains source code to 

    SQLite: An SQL Database Built Upon GDBM

To compile the project, first create a directory in which to place
the build products.  The build directory must be separate from the
source tree.  Cd into the build directory and then from the build
directory run the configure script found at the root of the source
tree.  Then run "make".

**
** Author contact information:
**   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.  The routines in this file handle
** the following kinds of rules:
**
**     CREATE TABLE
**     DROP TABLE
**     CREATE INDEX
**     DROP INDEX
**     creating expressions and ID lists
**     COPY
**     VACUUM
**
** $Id: build.c,v 1.13 2000/06/02 13:27:59 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

  ** 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,        2, 1, MASTER_NAME},
      { OP_New,         2, 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,         2, 0, 0},
      { OP_Close,       2, 0, 0},
    };
    int n;
    Vdbe *v = pParse->pVdbe;
    int lbl1, lbl2;
    int i;

    if( v==0 ){
      v = pParse->pVdbe = sqliteVdbeCreate(pParse->db->pBe);
    }
    if( v==0 ) goto exit_create_index;
    sqliteVdbeAddOp(v, OP_Open, 0, 0, pTab->zName, 0);
    sqliteVdbeAddOp(v, OP_Open, 1, 1, pIndex->zName, 0);
    if( pStart && pEnd ){
      int base;
      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);
    }


    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);
    }
    sqliteVdbeAddOp(v, OP_MakeKey, pIndex->nField, 0, 0, 0);
    sqliteVdbeAddOp(v, OP_PutIdx, 1, 0, 0, 0);
    sqliteVdbeAddOp(v, OP_Goto, 0, lbl1, 0, 0);
    sqliteVdbeAddOp(v, OP_Noop, 0, 0, 0, lbl2);
    sqliteVdbeAddOp(v, OP_Close, 1, 0, 0, 0);
    sqliteVdbeAddOp(v, OP_Close, 0, 0, 0, 0);
  }

  /* Reclaim memory on an EXPLAIN call.
  */
  if( pParse->explain ){
    sqliteFree(pIndex);
  }

** 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 1.11 2000/06/02 13:27:59 drh Exp $
*/
#include "sqliteInt.h"
#include <gdbm.h>
#include <sys/stat.h>
#include <unistd.h>
#include <ctype.h>
#include <time.h>

  p->s[p->i] = p->s[p->j];
  p->s[p->j] = t;
  t = p->s[p->i] + p->s[p->j];
  return t & 0xff;
}

/*
** This routine opens a new database.  For the GDBM driver
** implemented here, the database name is the name of the directory
** containing all the files of the database.
**
** If successful, a pointer to the Dbbe structure is returned.
** If there are errors, an appropriate error message is left
** in *pzErrMsg and NULL is returned.
*/
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, createFlag ? 
         "can't find or create directory \"" : "can't find directory \"",
         zName, "\"", 0);
      return 0;
    }
  }
  if( !S_ISDIR(statbuf.st_mode) ){
    sqliteSetString(pzErrMsg, "not a directory: \"", zName, "\"", 0);
    return 0;

    }
  }
  return zFile;
}

/*
** Generate a random filename with the given prefix.
**
** Very random names are chosen so that the chance of a
** collision with an existing filename is very very small.
*/
static void randomName(struct rc4 *pRc4, char *zBuf, char *zPrefix){
  int i, j;
  static const char zRandomChars[] = "abcdefghijklmnopqrstuvwxyz0123456789";
  strcpy(zBuf, zPrefix);
  j = strlen(zBuf);
  for(i=0; i<15; i++){
    int c = rc4byte(pRc4) % (sizeof(zRandomChars) - 1);
    zBuf[j++] = zRandomChars[c];
  }
  zBuf[j] = 0;
}


/*
** Open a new table cursor.  Write a pointer to the corresponding
** DbbeTable structure into *ppTable.  Return an integer success
** code:
**
**    SQLITE_OK          It worked!
**
**    SQLITE_NOMEM       sqliteMalloc() failed
**
**    SQLITE_PERM        Attempt to access a file for which file
**                       access permission is denied
**
**    SQLITE_BUSY        Another thread or process is already using
**                       the corresponding file and has that file locked.
**
**    SQLITE_READONLY    The current thread already has this file open
**                       readonly but you are trying to open for writing.
**                       (This can happen if a SELECT callback tries to
**                       do an UPDATE or DELETE.)
**
** If zTable is 0 or "", then a temporary table is created and opened.
** This table will be deleted from the disk when it is closed.
*/
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 */
){

  pTable->readPending = 0;
  pTable->needRewind = 1;
  *ppTable = pTable;
  return rc;
}

/*
** Drop a table from the database.  The file on the disk that corresponds
** to this table is deleted.
*/
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){

  DbbeTable *pTab;

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

  key.dptr = pKey;
  rc = gdbm_delete(pTable->pFile->dbf, key);
  if( rc ) rc = SQLITE_ERROR;
  return rc;
}

/*
** Open a temporary file.  The file should be deleted when closed.
**
** Note that we can't use the old Unix trick of opening the file
** and then immediately unlinking the file.  That works great
** under Unix, but fails when we try to port to Windows.
*/
int sqliteDbbeOpenTempFile(Dbbe *pBe, FILE **ppFile){
  char *zFile;         /* Full name of the temporary file */
  char zBuf[50];       /* Base name of the temporary file */
  int i;               /* Loop counter */
  int limit;           /* Prevent an infinite loop */
  int rc = SQLITE_OK;  /* Value returned by this function */

  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*) );

** Author contact information:
**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*************************************************************************
** This file contains C code routines used for processing expressions
**
** $Id: expr.c,v 1.2 2000/06/02 13:27:59 drh Exp $
*/
#include "sqliteInt.h"

/*
** This routine walks an expression tree and resolves references to
** table fields.  Nodes of the form ID.ID or ID resolve into an
** index to the table in the table list and a field offset.  The opcode

      }
      pExpr->op = TK_FIELD;
      break; 
    }
  
    /* A table name and field name:  ID.ID */
    case TK_DOT: {
      int cnt = 0;             /* Number of matches */
      int i;                   /* Loop counter */
      Expr *pLeft, *pRight;    /* Left and right subbranches of the expr */

      char *zLeft, *zRight;    /* Text of an identifier */

      pLeft = pExpr->pLeft;
      pRight = pExpr->pRight;
      assert( pLeft && pLeft->op==TK_ID );
      assert( pRight && pRight->op==TK_ID );
      zLeft = 0;

**   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 1.3 2000/06/02 13:27:59 drh Exp $
*/
#include "sqliteInt.h"

/*
** This routine is call to handle SQL of the following form:
**
**    insert into TABLE (IDLIST) values(EXPRLIST)
**
** The parameters are the table name and the expression list.
*/
void sqliteInsert(
  Parse *pParse,        /* Parser context */
  Token *pTableName,    /* Name of table into which we are inserting */
  ExprList *pList,      /* List of values to be inserted */
  IdList *pField        /* Field name corresponding to pList.  Might be NULL */
){
  Table *pTab;
  char *zTab;
  int i, j, idx;
  Vdbe *v;

  zTab = sqliteTableNameFromToken(pTableName);
  pTab = sqliteFindTable(pParse->db, zTab);
  sqliteFree(zTab);
  if( pTab==0 ){
    sqliteSetNString(&pParse->zErrMsg, "no such table: ", 0, 

      }
    }
  }
  v = pParse->pVdbe = sqliteVdbeCreate(pParse->db->pBe);
  if( v ){
    Index *pIdx;
    sqliteVdbeAddOp(v, OP_Open, 0, 1, pTab->zName, 0);
    for(idx=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, idx++){
      sqliteVdbeAddOp(v, OP_Open, idx, 1, pIdx->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;

      }else{
        sqliteExprCode(pParse, pList->a[j].pExpr);
      }
    }
    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(idx=1, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, idx++){
      if( pIdx->pNext ){
        sqliteVdbeAddOp(v, OP_Dup, 0, 0, 0, 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;
          }
        }
        if( pField && j>=pField->nId ){
          sqliteVdbeAddOp(v, OP_String, 0, 0, "", 0);
        }else{
          sqliteExprCode(pParse, pList->a[j].pExpr);
        }
      }
      sqliteVdbeAddOp(v, OP_MakeKey, pIdx->nField, 0, 0, 0);
      sqliteVdbeAddOp(v, OP_PutIdx, idx, 0, 0, 0);
      sqliteVdbeAddOp(v, OP_Close, idx, 0, 0, 0);
    }
  }

insert_cleanup:
  sqliteExprListDelete(pList);
  sqliteIdListDelete(pField);
}

**
*************************************************************************
** 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 1.6 2000/06/02 13:27:59 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

  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.
**
** After the database is initialized, the SQLITE_Initialized
** bit is set in the flags field of the sqlite structure.  An
** attempt is made to initialize the database as soon as it
** is opened.  If that fails (perhaps because another process
** has the sqlite_master table locked) than another attempt
** is made the first time the database is accessed.
*/
static int sqliteInit(sqlite *db, char **pzErrMsg){
  Vdbe *vdbe;
  int rc;

  /*
  ** The master database table has a structure like this

  }

  /* Attempt to read the schema */
  rc = sqliteInit(db, pzErrMsg);
  if( rc!=SQLITE_OK && rc!=SQLITE_BUSY ){
    sqlite_close(db);
    return 0;
  }else{
    sqliteFree(pzErrMsg);
    *pzErrMsg = 0;
  }
  return db;
}

/*
** Close an existing SQLite database
*/

    }
    i += n;
  }
  return lastWasSemi;
}

/*
** Execute SQL code.  Return one of the SQLITE_ success/failure
** codes.  Also write an error message into memory obtained from
** malloc() and make *pzErrMsg point to that message.
**
** If the SQL is a query, then for each row in the query result
** the xCallback() function is called.  pArg becomes the first
** argument to xCallback().  If xCallback=NULL then no callback
** is invoked, even for queries.
*/
int sqlite_exec(
  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 */

**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*************************************************************************
** This file contains code to implement the "sqlite" command line
** utility for accessing SQLite databases.
**
** $Id: shell.c,v 1.6 2000/06/02 13:27:59 drh Exp $
*/
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include "sqlite.h"
#include <unistd.h>
#include <ctype.h>

**
** The interface is like "readline" but no command-line editing
** is done.
*/
static char *getline(char *zPrompt){
  char *zLine;
  int nLine;

  int n;
  int eol;

  if( zPrompt && *zPrompt ){
    printf("%s",zPrompt);
    fflush(stdout);
  }

      argc--;
      argv++;
    }else if( strcmp(argv[1],"-line")==0 ){
      data.mode = MODE_Line;
      argc--;
      argv++;
    }else if( argc>=3 && strcmp(argv[0],"-separator")==0 ){
      sprintf(data.separator,"%.*s",(int)sizeof(data.separator)-1,argv[2]);
      argc -= 2;
      argv += 2;
    }else if( strcmp(argv[1],"-header")==0 ){
      data.showHeader = 1;
      argc--;
      argv++;
    }else if( strcmp(argv[1],"-noheader")==0 ){

** Author contact information:
**   drh@hwaci.com
**   http://www.hwaci.com/drh/
**
*************************************************************************
** Internal interface definitions for SQLite.
**
** @(#) $Id: sqliteInt.h,v 1.10 2000/06/02 13:28:00 drh Exp $
*/
#include "sqlite.h"
#include "dbbe.h"
#include "vdbe.h"
#include "parse.h"
#include <gdbm.h>
#include <stdio.h>

void sqliteCopy(Parse*, Token*, Token*, Token*);
void sqliteVacuum(Parse*, Token*);
int sqliteGlobCompare(const char*,const char*);
int sqliteLikeCompare(const unsigned char*,const unsigned char*);
char *sqliteTableNameFromToken(Token*);
int sqliteExprCheck(Parse*, Expr*, int, int*);
int sqliteFuncId(Token*);
int sqliteExprResolveIds(Parse*, IdList*, Expr*);

**
*************************************************************************
** Utility functions used throughout sqlite.
**
** This file contains functions for allocating memory, comparing
** strings, and stuff like that.
**
** $Id: util.c,v 1.9 2000/06/02 13:28:00 drh Exp $
*/
#include "sqliteInt.h"
#include <stdarg.h>
#include <ctype.h>

#ifdef MEMORY_DEBUG

**
** This routine is just an adaptation of the sqliteGlobCompare()
** routine above.
*/
int 
sqliteLikeCompare(const unsigned char *zPattern, const unsigned char *zString){
  register char c;


  char c2;

  while( (c = UpperToLower[*zPattern])!=0 ){
    switch( c ){
      case '%':
        while( zPattern[1]=='%' ) zPattern++;
        if( zPattern[1]==0 ) return 1;

# Copyright (c) 1999, 2000 D. Richard Hipp
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public
# License as published by the Free Software Foundation; either
# version 2 of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# General Public License for more details.
# 
# You should have received a copy of the GNU General Public
# License along with this library; if not, write to the
# Free Software Foundation, Inc., 59 Temple Place - Suite 330,
# Boston, MA  02111-1307, USA.
#
# Author contact information:
#   drh@hwaci.com
#   http://www.hwaci.com/drh/
#
#***********************************************************************
# This file implements regression tests for SQLite library.  The
# focus of this file is testing the SELECT statement.
#
# $Id: select2.test,v 1.1 2000/06/02 13:28:16 drh Exp $

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

execsql {CREATE TABLE tbl1(f1 int, f2 int)}
for {set i 0} {$i<=30} {incr i} {
  execsql "INSERT INTO tbl1 VALUES([expr {$i%9}],[expr {$i%10}])"
}

# Do a second query inside a first.
#
do_test select2-1.1 {
  set sql {SELECT DISTINCT f1 FROM tbl1 ORDER BY f1}
  set r {}
  db eval $sql data {
    set f1 $data(f1)
    lappend r $f1:
    set sql2 "SELECT f2 FROM tbl1 WHERE f1=$f1 ORDER BY f2"
    db eval $sql2 d2 {
      lappend r $d2(f2)
    }
  }
  set r
} {0: 0 7 8 9 1: 0 1 8 9 2: 0 1 2 9 3: 0 1 2 3 4: 2 3 4 5: 3 4 5 6: 4 5 6 7: 5 6 7 8: 6 7 8}


do_test select2-1.2 {
  set sql {SELECT DISTINCT f1 FROM tbl1 WHERE f1>3 AND f1<5}
  set r {}
  db eval $sql data {
    set f1 $data(f1)
    lappend r $f1:
    set sql2 "SELECT f2 FROM tbl1 WHERE f1=$f1 ORDER BY f2"
    db eval $sql2 d2 {
      lappend r $d2(f2)
    }
  }
  set r
} {4: 2 3 4}

finish_test

#
# Run this Tcl script to generate the sqlite.html file.
#
set rcsid {$Id: c_interface.tcl,v 1.3 2000/06/02 13:28:00 drh Exp $}

puts {<html>
<head>
  <title>The C language interface to the SQLite library</title>
</head>
<body bgcolor=white>
<h1 align=center>
The C language interface to the SQLite library
</h1>}
puts "<p align=center>
(This page was last modified on [lrange $rcsid 3 4] GMT)
</p>"

puts {
<p>The SQLite library is designed to be very easy to use from
a C or C++ program.  This document gives an overview of the C/C++
programming interface.</p>

<h2>The API</h2>

<p>The interface to the SQLite library consists of 4 functions,
one opaque data structure, and some constants used as return
values from sqlite_exec():</p>

<blockquote><pre>
typedef struct sqlite sqlite;

sqlite *sqlite_open(const char *filename, int mode, char **errmsg);

void sqlite_close(sqlite*);

int sqlite_exec(
  sqlite*,
  char *sql,
  int (*)(void*,int,char**,char**),
  void*,
  char **errmsg
);

int sqlite_complete(const char *sql);

#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_PERM      3    /* Access permission denied */
#define SQLITE_ABORT     4    /* Callback routine requested an abort */
#define SQLITE_BUSY      5    /* One or more database files are locked */
#define SQLITE_NOMEM     6    /* A malloc() failed */
#define SQLITE_READONLY  7    /* Attempt to write a readonly database */
</pre></blockquote>

<p>All of the above definitions are included in the "sqlite.h"
header file that comes in the source tree.</p>

<h2>Opening a database</h2>

<p>Use the <b>sqlite_open()</b> function to open an existing SQLite
database or to create a new SQLite database.  The first argument
is the database name.  The second argument is a constant 0666 to
open the database for reading and writing and 0444 to open the
database read only.  The third argument is a pointer to a string
pointer.  If the third argument is not NULL and an error occurs
while trying to open the database, then an error message will be
written to memory obtained from malloc() and *errmsg will be made

<p>To create a new SQLite database, all you have to do is call
<b>sqlite_open()</b> with the first parameter set to the name of
an empty directory and the second parameter set to 0666.</p>

<p>The return value of the <b>sqlite_open()</b> function is a
pointer to an opaque <b>sqlite</b> structure.  This pointer will
be the first argument to all subsequent SQLite function calls that
deal with the same database.  NULL is returned if the open fails
for any reason.</p>

<h2>Closing the database</h2>

<p>To close an SQLite database, just call the <b>sqlite_close()</b>
function passing it the sqlite structure pointer that was obtained
from a prior call to <b>sqlite_open</b>.

<h2>Executing SQL statements</h2>

<p>The <b>sqlite_exec()</b> function is used to process SQL statements
and queries.  This function requires 5 parameters as follows:</p>

<ol>
<li><p>A pointer to the sqlite structure obtained from a prior call
       to <b>sqlite_open()</b>.</p></li>
<li><p>A null-terminated string containing the text of one or more
       SQL statements and/or queries to be processed.</p></li>
<li><p>A pointer to a callback function which is invoked once for each
       row in the result of a query.  This argument may be NULL, in which
       case no callbacks will ever be invoked.</p></li>
<li><p>A pointer that is forwarded to become the first argument
       to the callback function.</p></li>
<li><p>A pointer to an error string.  Error messages are written to space
       obtained from malloc() and the error string is made to point to
       the malloced space.  The calling function is responsible for freeing
       this space when it has finished with it.
       This argument may be NULL, in which case error messages are not
       reported back to the calling function.</p></li>
</ol>

<p>
The callback function is used to receive the results of a query.  A
prototype for the callback function is as follows:</p>

<blockquote><pre>
int Callback(void *pArg, int argc, char **argv, char **columnNames){
  return 0;
}
</pre></blockquote>

<p>The first argument to the callback is just a copy of the fourth argument
to <b>sqlite_exec()</b>  This parameter can be used to pass arbitrary
information through to the callback function from client code.
The second argument is the number columns in the query result.
The third argument is an array of pointers to strings where each string
is a single column of the result for that record.  The names of the
columns are contained in the fourth argument.</p>

<p>The callback function should normally return 0.  If the callback
function returns non-zero, the query is immediately aborted and 
<b>sqlite_exec()</b> will return SQLITE_ABORT.</p>

<h2>Testing for a complete SQL statement</h2>

<p>The last interface routine to SQLite is a convenience function used
to test whether or not a string forms a complete SQL statement.
If the <b>sqlite_complete()</b> function returns true when its input
is a string, then the argument forms a complete SQL statement.
There are no guarantees that the syntax of that statement is correct,
but we at least know the statement is complete.  If <b>sqlite_complete()</b>
returns false, then more text is required to complete the SQL statement.</p>

<p>For the purpose of the <b>sqlite_complete()</b> function, an SQL
statement is complete if it ends in a semicolon.</p>

<p>The <b>sqlite</b> command-line utility uses the <b>sqlite_complete()</b>
function to know when it needs to call <b>sqlite_exec()</b>.  After each
line of input is received, <b>sqlite</b> calls <b>sqlite_complete()</b>
on all input in its buffer.  If <b>sqlite_complete()</b> returns true, 
then <b>sqlite_exec()</b> is called and the input buffer is reset.  If
<b>sqlite_complete()</b> returns false, then the prompt is changed to
the continuation prompt and another line of text is read and added to
the input buffer.</p>

<h2>Usage Examples</h2>

<p>For examples of how the SQLite C/C++ interface can be used,
refer to the source code for the <b>sqlite</b> program in the
file <b>src/shell.c</b> of the source tree.
Additional information about sqlite is available at
<a href="sqlite.html">sqlite.html</a>.
See also the sources to the Tcl interface for SQLite in
the source file <b>src/tclsqlite.c</b>.</p>
}

puts {
<p><hr /></p>
<p><a href="index.html"><img src="/goback.jpg" border=0 />
Back to the SQLite Home Page</a>
</p>

</body></html>}

}


proc chng {date desc} {
  puts "<DT><B>$date</B></DT>"
  puts "<DD><P><UL>$desc</UL></P></DD>"
}

chng {2000 June 2} {
<li>All database files to be modified by an UPDATE, INSERT or DELETE are 
now locked before any changes are made to any files.  
This makes it safe (I think) to access
the same database simultaneously from multiple processes.</li>
<li>The code appears stable so we are now calling it "beta".</li>
}

chng {2000 June 1} {
<li>Better support for file locking so that two or more processes 
(or threads)
can access the same database simultaneously.  More work needed in
this area, though.</li>
}

chng {2000 May 31} {
<li>Added support for aggregate functions (Ex: <b>COUNT(*)</b>, <b>MIN(...)</b>)
to the SELECT statement.</li>
<li>Added support for <B>SELECT DISTINCT ...</B></li>
}

#
# Run this TCL script to generate HTML for the index.html file.
#
set rcsid {$Id: index.tcl,v 1.10 2000/06/02 13:28:00 drh Exp $}

puts {<html>
<head><title>SQLite: An SQL Database Built Atop GDBM</title></head>
<body bgcolor=white>
<h1 align=center>SQLite: An SQL Database Built Upon 
<a href="http://www.gnu.org/software/gdbm/gdbm.html">GDBM</a></h1>
<p align=center>}
puts "This page was last modified on [lrange $rcsid 3 4] GMT<br>"
puts "The SQLite source code was last modifed on [exec cat last_change] GMT"
puts {</p>}

puts {
<h2>News</h2>
<p>
Though still relatively new, 
the SQLite code base appears to be working well and has therefore

been upgraded to "beta" status.
There are currently no known errors in the code.


One very large database (1M+ records in 50+ separate tables) has
been converted from PostgreSQL and gives every appearance of working
correctly.</p>

<p>Your constructive comments are still very important to us.
Please visit the 
<a href="#mailinglist">mailing list</a> to offer feedback.</p>

}

puts {<h2>Introduction</h2>

<p>SQLite is an SQL database built atop the 
<a href="http://www.gnu.org/software/gdbm/gdbm.html">GDBM library</a>.
The SQLite distribution includes both a interactive command-line
access program (<b>sqlite</b>) and a C library (<b>libsqlite.a</b>)
that can be linked
with a C/C++ program to provide SQL database access without having
to rely on an external RDBMS.</p>

<p>The C interface to SQLite is very simple, consisting of only
four functions, a single opaque data structure, and a handful of
constants that define error return codes.
See <a href="c_interface.html">c_interface.html</a> for details.
A Tcl interface
to SQLite is also available and is included in the source tree.
Documentation on the Tcl interface is pending.
Interfaces for perl and python may be supplied in future releases.</p>

<p>The standalone program <b>sqlite</b> can be used
to interactively create, update and/or query an SQLite database.
The sources to the sqlite program are part of the source tree and
can be used as an example of how to interact with the SQLite C
library.  For more information on the sqlite program,
see <a href="sqlite.html">sqlite.html</a>.</p>

<p>A history of changes to SQLite is found
<a href="changes.html">here</a>.</p>

<p>SQLite is intended to be small and light-weight.
It does not try to implement every feature of SQL. 
A few of the many SQL features that SQLite does not (currently) 
implement are as follows:</p>

<p>
<ul>
<li>The GROUP BY or HAVING clauses of a SELECT</li>
<li>Constraints</li>

puts {<h2>Download</h2>

<p>You can download a tarball containing all C source
code for SQLite at <a href="sqlite.tar.gz">sqlite.tar.gz</a>.}
puts "This is a [file size sqlite.tar.gz] byte download.  The
tarball was last modified at [clock format [file mtime sqlite.tar.gz]]"
puts {</p>

<p>To build sqlite, just unwrap the tarball, create a separate
build directory, run configure from the build directory and then
type "make".  For example:</p>

<blockquote><pre>
$ tar xzf sqlite.tar.gz   ;# Unpacks into directory named "sqlite"
$ mkdir bld               ;# Create a separate build directory
$ cd bld
$ ../sqlite/configure
$ make                    ;# Builds "sqlite" and "libsqlite.a"
$ make test               ;# Optional: run regression tests
</pre></blockquote>

<p>You can also download a larger tarball that contains everything
in the source tarball plus all of the sources for the text that
appears on this website, and other miscellaneous files.  The
complete tarball is found at <a href="all.tar.gz">all.tar.gz</a>.}
puts "This is a [file size all.tar.gz] byte download and was
was last modified at [clock format [file mtime sqlite.tar.gz]]</p>"

<li><p>Someday, we would like to port SQLite to work with
       the Berkeley DB library in addition to GDBM.  For information
       about the Berkeley DB library, see
       <a href="http://www.sleepycat.com/">http://www.sleepycat.com/</a>
       </p></li>

<li><p>Here is a good <a href="http://w3.one.net/~jhoffman/sqltut.htm">
       tutorial on SQL</a>.</p></li>

<li><p><a href="http://www.postgresql.org/">PostgreSQL</a> is a
       full-blown SQL RDBMS that is also open source.</p></li>
</ul>}

puts {
<p><hr /></p>
<p>
<a href="../index.html"><img src="/goback.jpg" border=0 />
More Open Source Software</a> from Hwaci.
</p>

</body></html>}

#
# Run this Tcl script to generate the sqlite.html file.
#
set rcsid {$Id: sqlite.tcl,v 1.6 2000/06/02 13:28:00 drh Exp $}

puts {<html>
<head>
  <title>sqlite: A program of interacting with SQLite databases</title>
</head>
<body bgcolor=white>
<h1 align=center>

<p>To start the <b>sqlite</b> program, just type "sqlite" followed by
the name of an SQLite database.  An SQLite database is really just
a directory full of GDBM files, so the argument to the sqlite command
should really be the name of a directory on your disk.  If that
directory did not previously contain an SQLite database, a new one
is created for you automatically.  The <b>sqlite</b> program will
prompt you to enter SQL.  Type in SQL statements (terminated by a
semicolon), press "Enter" and the SQL will be executed.  It's as
simple as that!</p>

<p>For example, to create a new SQLite database named "ex1" 
with a single table named "tbl1", you might do this:</p>
}

proc Code {body} {

$ (((mkdir ex1)))
$ (((sqlite ex1)))
Enter ".help" for instructions
sql> (((create table tbl1(one varchar(10), two smallint);)))
sql> (((insert into tbl1 values('hello!',10);)))
sql> (((insert into tbl1 values('goodbye', 20);)))
sql> (((select * from tbl1;)))
hello!|10


goodbye|20

sql>
}

puts {
<p>(In the example above, and in all subsequent examples, the commands
you type are shown with a green tint in an italic font and the responses
from the computer are shown in black with a constant-width font.)</p>

<p>You can terminate the sqlite program by typing your systems
End-Of-File character (usually a Control-D) or the interrupt
character (usually a Control-C).</p>

<p>Make sure you type a semicolon at the end of each SQL command!
The sqlite looks for a semicolon to know when your SQL command is
complete.  If you omit the semicolon, sqlite will give you a
continuation prompt and wait for you to enter more text to be
added to the current SQL command.  This feature allows you to
enter SQL commands that span multiple lines.  For example:</p>
}

sql = create table tbl1(one varchar(10), two smallint)
sql>
}

puts {
<p>
But you cannot execute DROP TABLE, UPDATE, INSERT or DELETE against
the sqlite_master table.  The sqlite_master
table is updated automatically as you create or drop tables and
indices from the database.  You can not make manual changes
to the sqlite_master table.
</p>

<h2>Special commands to sqlite</h2>

<p>
Most of the time, sqlite just reads lines of input and passes them
on to the SQLite library for execution.
But if an input line begins with a dot ("."), then
that line is intercepted and interpreted by the sqlite program itself.
These "dot commands" are typically used to change the output format
of queries, or to execute certain prepackaged query statements.
</p>

<p>
For a listing of the available dot commands, you can enter ".help"
at any time.  For example:
</p>}

one = goodbye
two = 20
sql>
}

puts {
<p>Line mode used to be the default mode setting.  But after some
experience using the utility, it was decided that "list" mode made
a better default and so now the default mode is "list".</p>
}

puts {
<p>In column mode, each record is shown on a separate line with the
data aligned in columns.  For example:</p>}

Code {

------------  ------
hello         10    
goodbye       20    
sql>
}

puts {
<p>The ".width" command in the example above sets the width of the first
column to 12 and the width of the second column to 6.  All other column
widths were unaltered.  You can gives as many arguments to ".width" as
necessary to specify the widths of as many columns as are in your
query results.</p>

<p>The column labels that appear on the first two lines of output
can be turned on and off using the ".header" dot command.  In the

puts {
<p>The third output mode supported by sqlite is called "list".  In
list mode, each record of a query result is written on one line of
output and each field within that record is separated by a specific
separator string.  The default separator is a pipe symbol ("|").
List mode is especially useful when you are going to send the output
of a query to another program (such as AWK) for additional processing.</p>}

Code {
sql> (((.mode list)))
sql> (((select * from tbl1;)))
hello|10
goodbye|20
sql>

list mode, then entering the following query:</p>

<blockquote><pre>
SELECT sql FROM sqlite_master
ORDER BY tbl_name, type DESC, name
</pre></blockquote>

<p>Or, if you give an argument to ".schema" because you only
want the schema for a single table, the query looks like this:</p>

<blockquote><pre>
SELECT sql FROM sqlite_master
WHERE tbl_name LIKE '%s'
ORDER BY type DESC, name
</pre></blockquote>

<p>The <b>%s</b> in the query above is replaced by the argument
to ".schema", of course.</p>

<h2>Other Dot Commands</h2>

<p>The ".explain" dot command can be used to set the output mode
to "column" and to set the column widths to values that are reasonable
for looking at the output of an EXPLAIN command.  The EXPLAIN command
is an SQLite-specific SQL extension that is useful for debugging.  If any
regular SQL is prefaced by EXPLAIN, then the SQL command is parsed and
analyzed but is not executed.  Instead, the sequence of virtual machine
instructions that would have been used to execute the SQL command are
returned like a query result.  For example:</p>}

Code {
sql> (((.explain)))
sql> (((explain delete from tbl1 where two<20;)))
addr  opcode        p1     p2     p3          
----  ------------  -----  -----  -------------------------------------   
0     ListOpen      0      0                  
1     Open          0      1      tbl1        
2     Next          0      9                  
3     Field         0      1                  
4     Integer       20     0                  
5     Ge            0      2                  
6     Key           0      0                  
7     ListWrite     0      0                  
8     Goto          0      2