SQLite

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains routines used for analyzing expressions and
** for generating VDBE code that evaluates expressions in SQLite.
**
** $Id: expr.c,v 1.43 2002/02/23 23:45:45 drh Exp $
*/
#include "sqliteInt.h"


/*
** Construct a new expression node and return a pointer to it.  Memory
** for this node is obtained from sqliteMalloc().  The calling function

  switch( pExpr->op ){
    case TK_FUNCTION: {
      int id = sqliteFuncId(&pExpr->token);
      int n = pExpr->pList ? pExpr->pList->nExpr : 0;
      int no_such_func = 0;
      int too_many_args = 0;
      int too_few_args = 0;
      int wrong_num_args = 0;
      int is_agg = 0;
      int i;
      pExpr->iColumn = id;
      switch( id ){
        case FN_Unknown: {
          UserFunc *pUser = sqliteFindUserFunction(pParse->db,
             pExpr->token.z, pExpr->token.n, n, 0);
          if( pUser==0 ){
            pUser = sqliteFindUserFunction(pParse->db,
               pExpr->token.z, pExpr->token.n, -1, 0);
            if( pUser==0 ){
              no_such_func = 1;
            }else{
              wrong_num_args = 1;
            }
          }else{
            is_agg = pUser->xFunc==0;
          }
          break;
        }
        case FN_Count: { 

          too_many_args = n>1;
          is_agg = 1;
          break;
        }
        case FN_Max:
        case FN_Min: {
          too_few_args = n<1;
          is_agg = n==1;
          break;
        }
        case FN_Avg:
        case FN_Sum: {

          too_many_args = n>1;
          too_few_args = n<1;
          is_agg = 1;
          break;
        }
        case FN_Abs:
        case FN_Length: {

        case FN_Substr: {
          too_few_args = n<3;
          too_many_args = n>3;
          break;
        }
        default: break;
      }
      if( is_agg && !allowAgg ){
        sqliteSetNString(&pParse->zErrMsg, "misuse of aggregate function ", -1,
           pExpr->token.z, pExpr->token.n, "()", 2, 0);
        pParse->nErr++;
        nErr++;
        is_agg = 0;
      }else if( no_such_func ){
        sqliteSetNString(&pParse->zErrMsg, "no such function: ", -1,
           pExpr->token.z, pExpr->token.n, 0);
        pParse->nErr++;
        nErr++;
      }else if( too_many_args ){
        sqliteSetNString(&pParse->zErrMsg, "too many arguments to function ",-1,
           pExpr->token.z, pExpr->token.n, "()", 2, 0);
        pParse->nErr++;
        nErr++;
      }else if( too_few_args ){
        sqliteSetNString(&pParse->zErrMsg, "too few arguments to function ",-1,
           pExpr->token.z, pExpr->token.n, "()", 2, 0);
        pParse->nErr++;
        nErr++;
      }else if( wrong_num_args ){
        sqliteSetNString(&pParse->zErrMsg, 
           "wrong number of arguments to function ",-1,
           pExpr->token.z, pExpr->token.n, "()", 2, 0);
        pParse->nErr++;
        nErr++;
      }
      if( is_agg ) pExpr->op = TK_AGG_FUNCTION;
      if( is_agg && pIsAgg ) *pIsAgg = 1;
      for(i=0; nErr==0 && i<n; i++){
        nErr = sqliteExprCheck(pParse, pExpr->pList->a[i].pExpr,
                               allowAgg && !is_agg, pIsAgg);

        }
        case FN_Substr: {
          for(i=0; i<pList->nExpr; i++){
            sqliteExprCode(pParse, pList->a[i].pExpr);
          }
          sqliteVdbeAddOp(v, OP_Substr, 0, 0);
          break;
        }
        case FN_Unknown: {
          UserFunc *pUser;
          pUser = sqliteFindUserFunction(pParse->db,
                      pExpr->token.z, pExpr->token.n, pList->nExpr, 0);
          assert( pUser!=0 );
          for(i=0; i<pList->nExpr; i++){
            sqliteExprCode(pParse, pList->a[i].pExpr);
          }
          sqliteVdbeAddOp(v, OP_UserFunc, pList->nExpr, 0);
          sqliteVdbeChangeP3(v, -1, (char*)pUser->xFunc, P3_POINTER);
          break;
        }
        default: {
          /* Can't happen! */
          break;
        }
      }
      break;

        }
      }
      break;
    }
  }
  return nErr;
}

/*
** Locate a user function given a name and a number of arguments.
** Return a pointer to the UserFunc structure that defines that
** function, or return NULL if the function does not exist.
**
** If the createFlag argument is true, then a new (blank) UserFunc
** structure is created and liked into the "db" structure if a
** no matching function previously existed.  When createFlag is true
** and the nArg parameter is -1, then only a function that accepts
** any number of arguments will be returned.
**
** If createFlag is false and nArg is -1, then the first valid
** function found is returned.  A function is valid if either xFunc
** or xStep is non-zero.
*/
UserFunc *sqliteFindUserFunction(
  sqlite *db,        /* An open database */
  const char *zName, /* Name of the function.  Not null-terminated */
  int nName,         /* Number of characters in the name */
  int nArg,          /* Number of arguments.  -1 means any number */
  int createFlag     /* Create new entry if true and does not otherwise exist */
){
  UserFunc *pFirst, *p, *pMaybe;
  pFirst = p = (UserFunc*)sqliteHashFind(&db->userFunc, zName, nName);
  if( !createFlag && nArg<0 ){
    while( p && p->xFunc==0 && p->xStep==0 ){ p = p->pNext; }
    return p;
  }
  pMaybe = 0;
  while( p && p->nArg!=nArg ){
    if( p->nArg<0 && !createFlag && (p->xFunc || p->xStep) ) pMaybe = p;
    p = p->pNext;
  }
  if( p && !createFlag && p->xFunc==0 && p->xStep==0 ){
    return 0;
  }
  if( p==0 && pMaybe ){
    assert( createFlag==0 );
    return pMaybe;
  }
  if( p==0 && createFlag ){
    p = sqliteMalloc( sizeof(*p) );
    p->nArg = nArg;
    p->pNext = pFirst;
    sqliteHashInsert(&db->userFunc, zName, nName, (void*)p);
  }
  return p;
}

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This is the implementation of generic hash-tables
** used in SQLite.
**
** $Id: hash.c,v 1.7 2002/02/23 23:45:45 drh Exp $
*/
#include "sqliteInt.h"
#include <assert.h>

/* Turn bulk memory into a hash table object by initializing the
** fields of the Hash structure.
**

** new data replaces the old data and the old data is returned.
** The key is not copied in this instance.  If a malloc fails, then
** the new data is returned and the hash table is unchanged.
**
** If the "data" parameter to this function is NULL, then the
** element corresponding to "key" is removed from the hash table.
*/
void *sqliteHashInsert(Hash *pH, const void *pKey, int nKey, void *data){
  int hraw;             /* Raw hash value of the key */
  int h;                /* the hash of the key modulo hash table size */
  HashElem *elem;       /* Used to loop thru the element list */
  HashElem *new_elem;   /* New element added to the pH */
  int (*xHash)(const void*,int);  /* The hash function */

  assert( pH!=0 );

    new_elem->pKey = sqliteMalloc( nKey );
    if( new_elem->pKey==0 ){
      sqliteFree(new_elem);
      return data;
    }
    memcpy((void*)new_elem->pKey, pKey, nKey);
  }else{
    new_elem->pKey = (const void*)pKey;
  }
  new_elem->nKey = nKey;
  pH->count++;
  if( pH->htsize==0 ) rehash(pH,8);
  if( pH->htsize==0 ){
    pH->count = 0;
    sqliteFree(new_elem);

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** This is the header file for the generic hash-table implemenation
** used in SQLite.
**
** $Id: hash.h,v 1.4 2002/02/23 23:45:45 drh Exp $
*/
#ifndef _SQLITE_HASH_H_
#define _SQLITE_HASH_H_

/* Forward declarations of structures. */
typedef struct Hash Hash;
typedef struct HashElem HashElem;

#define SQLITE_HASH_STRING    3
#define SQLITE_HASH_BINARY    4

/*
** Access routines.  To delete, insert a NULL pointer.
*/
void sqliteHashInit(Hash*, int keytype, int copyKey);
void *sqliteHashInsert(Hash*, const void *pKey, int nKey, void *pData);
void *sqliteHashFind(const Hash*, const void *pKey, int nKey);
void sqliteHashClear(Hash*);

/*
** Macros for looping over all elements of a hash table.  The idiom is
** like this:
**

**
*************************************************************************
** 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 1.62 2002/02/23 23:45:45 drh Exp $
*/
#include <ctype.h>
#include "sqliteInt.h"
#include "os.h"

/*
** This is the callback routine for the code that initializes the
** database.  See sqliteInit() below for additional information.
**

** following global constant always lets us know.
*/
#ifdef SQLITE_UTF8
const char sqlite_encoding[] = "UTF-8";
#else
const char sqlite_encoding[] = "iso8859";
#endif

/*
** Implementation of the upper() and lower() SQL functions.
*/
static void upperFunc(void *context, int argc, const char **argv){
  char *z;
  int i;
  if( argc<1 || argv[0]==0 ) return;
  z = sqlite_set_result_string(context, argv[0], -1);
  if( z==0 ) return;
  for(i=0; z[i]; i++){
    if( islower(z[i]) ) z[i] = toupper(z[i]);
  }
}
static void lowerFunc(void *context, int argc, const char **argv){
  char *z;
  int i;
  if( argc<1 || argv[0]==0 ) return;
  z = sqlite_set_result_string(context, argv[0], -1);
  if( z==0 ) return;
  for(i=0; z[i]; i++){
    if( isupper(z[i]) ) z[i] = tolower(z[i]);
  }
}

/*
** 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

  db = sqliteMalloc( sizeof(sqlite) );
  if( pzErrMsg ) *pzErrMsg = 0;
  if( db==0 ) goto no_mem_on_open;
  sqliteHashInit(&db->tblHash, SQLITE_HASH_STRING, 0);
  sqliteHashInit(&db->idxHash, SQLITE_HASH_STRING, 0);
  sqliteHashInit(&db->tblDrop, SQLITE_HASH_POINTER, 0);
  sqliteHashInit(&db->idxDrop, SQLITE_HASH_POINTER, 0);
  sqliteHashInit(&db->userFunc, SQLITE_HASH_STRING, 1);
  sqlite_create_function(db, "upper", 1, upperFunc);
  sqlite_create_function(db, "lower", 1, lowerFunc);
  db->onError = OE_Default;
  db->priorNewRowid = 0;
  
  /* Open the backend database driver */
  rc = sqliteBtreeOpen(zFilename, mode, MAX_PAGES, &db->pBe);
  if( rc!=SQLITE_OK ){
    switch( rc ){

  return db->lastRowid;
}

/*
** Close an existing SQLite database
*/
void sqlite_close(sqlite *db){
  HashElem *i;
  sqliteBtreeClose(db->pBe);
  clearHashTable(db, 0);
  if( db->pBeTemp ){
    sqliteBtreeClose(db->pBeTemp);
  }
  for(i=sqliteHashFirst(&db->userFunc); i; i=sqliteHashNext(i)){
    UserFunc *pFunc, *pNext;
    for(pFunc = (UserFunc*)sqliteHashData(i); pFunc; pFunc=pNext){
      pNext = pFunc->pNext;
      sqliteFree(pFunc);
    }
  }
  sqliteHashClear(&db->userFunc);
  sqliteFree(db);
}

/*
** Return TRUE if the given SQL string ends in a semicolon.
*/
int sqlite_complete(const char *zSql){

/*
** Windows systems need functions to call to return the sqlite_version
** and sqlite_encoding strings.
*/
const char *sqlite_libversion(void){ return sqlite_version; }
const char *sqlite_libencoding(void){ return sqlite_encoding; }

/*
** Create new user-defined functions.  The sqlite_create_function()
** routine creates a regular function and sqlite_create_aggregate()
** creates an aggregate function.
**
** Passing a NULL xFunc argument or NULL xStep and xFinalize arguments
** disables the function.  Calling sqlite_create_function() with the
** same name and number of arguments as a prior call to
** sqlite_create_aggregate() disables the prior call to
** sqlite_create_aggregate(), and vice versa.
**
** If nArg is -1 it means that this function will accept any number
** of arguments, including 0.
*/
int sqlite_create_function(
  sqlite *db,          /* Add the function to this database connection */
  const char *zName,   /* Name of the function to add */
  int nArg,            /* Number of arguments */
  void (*xFunc)(void*,int,const char**)  /* Implementation of the function */
){
  UserFunc *p;
  if( db==0 || zName==0 ) return 1;
  p = sqliteFindUserFunction(db, zName, strlen(zName), nArg, 1);
  p->xFunc = xFunc;
  p->xStep = 0;
  p->xFinalize = 0;
  return 0;
}
int sqlite_create_aggregate(
  sqlite *db,          /* Add the function to this database connection */
  const char *zName,   /* Name of the function to add */
  int nArg,            /* Number of arguments */
  void *(*xStep)(void*,int,const char**), /* The step function */
  void (*xFinalize)(void*,void*)          /* The finalizer */
){
  UserFunc *p;
  if( db==0 || zName==0 ) return 1;
  p = sqliteFindUserFunction(db, zName, strlen(zName), nArg, 1);
  p->xFunc = 0;
  p->xStep = xStep;
  p->xFinalize = xFinalize;
  return 0;
}

**    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 1.26 2002/02/23 23:45:45 drh Exp $
*/
#ifndef _SQLITE_H_
#define _SQLITE_H_
#include <stdarg.h>     /* Needed for the definition of va_list */

/*
** The version of the SQLite library.

  char ***resultp,       /* Result written to a char *[]  that this points to */
  int *nrow,             /* Number of result rows written here */
  int *ncolumn,          /* Number of result columns written here */
  char **errmsg,         /* Error msg written here */
  va_list ap             /* Arguments to the format string */
);

/*
** Use the following routines to create new user-defined functions.  See
** the documentation for details.
*/
int sqlite_create_function(
  sqlite*,               /* Database where the new function is registered */
  const char *zName,     /* Name of the new function */
  int nArg,              /* Number of arguments.  -1 means any number */
  void (*xFunc)(void*,int,const char**)  /* C code to implement the function */
);
int sqlite_create_aggregate(
  sqlite*,               /* Database where the new function is registered */
  const char *zName,     /* Name of the function */
  int nArg,              /* Number of arguments */
  void *(*xStep)(void*,int,const char**), /* Called for each row */
  void (*xFinalize)(void*,void*)          /* Called once to get final result */
);

/*
** The user function implementations call one of the following four routines
** in order to return their results.  The first parameter to each of these
** routines is a copy of the first argument to xFunc() or the second argument
** to xFinalize().  The second parameter to these routines is the result
** to be returned.  A NULL can be passed as the second parameter to
** sqlite_set_result_string() in order to return a NULL result.
**
** The 3rd argument to _string and _error is the number of characters to
** take from the string.  If this argument is negative, then all characters
** up to and including the first '\000' are used.
*/
char *sqlite_set_result_string(void*,const char*,int);
void sqlite_set_result_int(void*,int);
void sqlite_set_result_double(void*,double);
void sqlite_set_result_error(void*,const char*,int);

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

#endif /* _SQLITE_H_ */

/*
** 2001 September 15
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    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 1.91 2002/02/23 23:45:45 drh Exp $
*/
#include "sqlite.h"
#include "hash.h"
#include "vdbe.h"
#include "parse.h"
#include "btree.h"
#include <stdio.h>

** an array.
*/
#define ArraySize(X)    (sizeof(X)/sizeof(X[0]))

/*
** Integer identifiers for built-in SQL functions.
*/
#define FN_Unknown    0      /* Not a built-in.  Might be user defined */
#define FN_Count      1
#define FN_Min        2
#define FN_Max        3
#define FN_Sum        4
#define FN_Avg        5
#define FN_Fcnt       6
#define FN_Length     7

typedef struct Parse Parse;
typedef struct Token Token;
typedef struct IdList IdList;
typedef struct WhereInfo WhereInfo;
typedef struct WhereLevel WhereLevel;
typedef struct Select Select;
typedef struct AggExpr AggExpr;
typedef struct UserFunc UserFunc;

/*
** Each database is an instance of the following structure
*/
struct sqlite {
  Btree *pBe;                   /* The B*Tree backend */
  Btree *pBeTemp;               /* Backend for session temporary tables */
  int flags;                    /* Miscellanous flags. See below */
  int file_format;              /* What file format version is this database? */
  int schema_cookie;            /* Magic number that changes with the schema */
  int next_cookie;              /* Value of schema_cookie after commit */
  int nTable;                   /* Number of tables in the database */
  void *pBusyArg;               /* 1st Argument to the busy callback */
  int (*xBusyCallback)(void *,const char*,int);  /* The busy callback */
  Hash tblHash;                 /* All tables indexed by name */
  Hash idxHash;                 /* All (named) indices indexed by name */
  Hash tblDrop;                 /* Uncommitted DROP TABLEs */
  Hash idxDrop;                 /* Uncommitted DROP INDEXs */
  Hash userFunc;                /* User defined functions */
  int lastRowid;                /* ROWID of most recent insert */
  int priorNewRowid;            /* Last randomly generated ROWID */
  int onError;                  /* Default conflict algorithm */
};

/*
** Possible values for the sqlite.flags.

                                          /*   DELETE, or UPDATE and return */
                                          /*   the count using a callback. */
#define SQLITE_NullCallback   0x00000080  /* Invoke the callback once if the */
                                          /*   result set is empty */
#define SQLITE_ResultDetails  0x00000100  /* Details added to result set */

/*
** Each user-defined function is defined by an instance of the following
** structure.  A pointer to this structure is stored in the sqlite.userFunc
** hash table.  When multiple functions have the same name, the hash table
** points to a linked list of these structures.
*/

struct UserFunc {
  void (*xFunc)(void*,int,const char**);   /* Regular function */
  void *(*xStep)(void*,int,const char**);  /* Aggregate function step */
  void (*xFinalize)(void*,void*);          /* Aggregate function finializer */
  int nArg;                                /* Number of arguments */
  UserFunc *pNext;                         /* Next function with same name */
};

/*
** information about each column of an SQL table is held in an instance
** of this structure.
*/
struct Column {
  char *zName;     /* Name of this column */

void sqliteCompleteInsertion(Parse*, Table*, int, char*, int, int);
void sqliteBeginWriteOperation(Parse*);
void sqliteBeginMultiWriteOperation(Parse*);
void sqliteEndWriteOperation(Parse*);
void sqliteExprMoveStrings(Expr*, int);
void sqliteExprListMoveStrings(ExprList*, int);
void sqliteSelectMoveStrings(Select*, int);
UserFunc *sqliteFindUserFunction(sqlite*,const char*,int,int,int);

** interface routines.  These are just wrappers around the main
** interface routine of sqlite_exec().
**
** These routines are in a separate files so that they will not be linked
** if they are not used.
*/
#include <stdlib.h>
#include <string.h>
#include "sqlite.h"

/*
** This structure is used to pass data from sqlite_get_table() through
** to the callback function is uses to build the result.
*/
typedef struct TabResult {

** 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 1.122 2002/02/23 23:45:45 drh Exp $
*/
#include "sqliteInt.h"
#include <ctype.h>

/*
** The following global variable is incremented every time a cursor
** moves, either by the OP_MoveTo or the OP_Next opcode.  The test

#define STK_Null      0x0001   /* Value is NULL */
#define STK_Str       0x0002   /* Value is a string */
#define STK_Int       0x0004   /* Value is an integer */
#define STK_Real      0x0008   /* Value is a real number */
#define STK_Dyn       0x0010   /* Need to call sqliteFree() on zStack[*] */
#define STK_Static    0x0020   /* zStack[] points to a static string */

/*
** The "context" argument for a user-defined function.
*/
struct UserFuncContext {
  Stack s;       /* Small string, integer, and floating point values go here */
  char *z;       /* Space for holding dynamic string results */
  int isError;   /* Set to true for an error */
};
typedef struct UserFuncContext UserFuncContext;

/*
** An Agg structure describes an Aggregator.  Each Agg consists of
** zero or more Aggregator elements (AggElem).  Each AggElem contains
** a key and one or more values.  The values are used in processing
** aggregate functions in a SELECT.  The key is used to implement
** the GROUP BY clause of a select.
*/

    }else{
      z[j++] = z[i++];
    }
  }
  while( j>0 && isspace(z[j-1]) ){ j--; }
  z[j] = 0;
}

/*
** The following group or routines are employed by user-defined functions
** to return their results.
**
** The sqlite_set_result_string() routine can be used to return a string
** value or to return a NULL.  To return a NULL, pass in NULL for zResult.
** A copy is made of the string before this routine returns so it is safe
** to pass in a ephemeral string.
**
** sqlite_set_result_error() works like sqlite_set_result_string() except
** that it signals a fatal error.  The string argument, if any, is the
** error message.  If the argument is NULL a generic substitute error message
** is used.
**
** The sqlite_set_result_int() and sqlite_set_result_double() set the return
** value of the user function to an integer or a double.
*/
char *sqlite_set_result_string(void *context, const char *zResult, int n){
  UserFuncContext *p = (UserFuncContext*)context;
  if( p->s.flags & STK_Dyn ){
    sqliteFree(p->z);
  }
  if( zResult==0 ){
    p->s.flags = STK_Null;
    n = 0;
    p->z = 0;
  }else{
    if( n<0 ) n = strlen(zResult);
    if( n<NBFS-1 ){
      memcpy(p->s.z, zResult, n);
      p->s.z[n] = 0;
      p->s.flags = STK_Str;
      p->z = p->s.z;
    }else{
      p->z = sqliteMalloc( n+1 );
      if( p->z ){
        memcpy(p->z, zResult, n);
        p->z[n] = 0;
      }
      p->s.flags = STK_Str | STK_Dyn;
    }
  }
  p->s.n = n;
  return p->z;
}
void sqlite_set_result_int(void *context, int iResult){
  UserFuncContext *p = (UserFuncContext*)context;
  if( p->s.flags & STK_Dyn ){
    sqliteFree(p->z);
  }
  p->s.i = iResult;
  p->s.flags = STK_Int;
}
void sqlite_set_result_double(void *context, double rResult){
  UserFuncContext *p = (UserFuncContext*)context;
  if( p->s.flags & STK_Dyn ){
    sqliteFree(p->z);
  }
  p->s.r = rResult;
  p->s.flags = STK_Real;
}
void sqlite_set_result_error(void *context, const char *zMsg, int n){
  UserFuncContext *p = (UserFuncContext*)context;
  sqlite_set_result_string(context, zMsg, n);
  p->isError = 1;
}

/*
** Reset an Agg structure.  Delete all its contents.
*/
static void AggReset(Agg *pAgg){
  int i;
  HashElem *p;

  "Divide",            "Remainder",         "BitAnd",            "BitOr",
  "BitNot",            "ShiftLeft",         "ShiftRight",        "AbsValue",
  "Precision",         "Min",               "Max",               "Like",
  "Glob",              "Eq",                "Ne",                "Lt",
  "Le",                "Gt",                "Ge",                "IsNull",
  "NotNull",           "Negative",          "And",               "Or",
  "Not",               "Concat",            "Noop",              "Strlen",
  "Substr",            "UserFunc",          "UserAgg",           "Limit",
};

/*
** Given the name of an opcode, return its number.  Return 0 if
** there is no match.
**
** This routine is used for testing and debugging.

    aStack[tos].flags = 0;
  }else{
    Release(p, tos);
  }
  p->tos = nos;
  break;
}

/* Opcode: UserFunc P1 * P3
**
** Invoke a user function (P3 is a pointer to the function) with
** P1 string arguments taken from the stack.  Pop all arguments from
** the stack and push back the result.
*/
case OP_UserFunc: {
  int n, i;
  UserFuncContext ctx;
  void (*xFunc)(void*,int,const char**);
  n = pOp->p1;
  VERIFY( if( n<=0 ) goto bad_instruction; )
  VERIFY( if( p->tos+1<n ) goto not_enough_stack; )
  for(i=p->tos-n+1; i<=p->tos; i++){
    if( (aStack[i].flags & STK_Null)==0 ){
      if( Stringify(p, i) ) goto no_mem;
    }
  }
  xFunc = (void(*)(void*,int,const char**))pOp->p3;
  ctx.s.flags = STK_Null;
  ctx.isError = 0;
  xFunc((void*)&ctx, n, (const char**)&zStack[p->tos-n+1]);
  PopStack(p, n);
  VERIFY( NeedStack(p, p->tos+1); )
  p->tos++;
  aStack[p->tos] = ctx.s;
  if( ctx.s.flags & STK_Dyn ){
    zStack[p->tos] = ctx.z;
  }else if( ctx.s.flags & STK_Str ){
    zStack[p->tos] = aStack[p->tos].z;
  }else{
    zStack[p->tos] = 0;
  }
  if( ctx.isError ){
    sqliteSetString(pzErrMsg, 
       zStack[p->tos] ? zStack[p->tos] : "user function error", 0);
    rc = SQLITE_ERROR;
  }
  break;
}

/* Opcode: BitAnd * * *
**
** Pop the top two elements from the stack.  Convert both elements
** to integers.  Push back onto the stack the bit-wise AND of the
** two elements.
*/

*************************************************************************
** Header file for the Virtual DataBase Engine (VDBE)
**
** This header defines the interface to the virtual database engine
** or VDBE.  The VDBE implements an abstract machine that runs a
** simple program to access and modify the underlying database.
**
** $Id: vdbe.h,v 1.45 2002/02/23 23:45:46 drh Exp $
*/
#ifndef _SQLITE_VDBE_H_
#define _SQLITE_VDBE_H_
#include <stdio.h>

/*
** A single VDBE is an opaque structure named "Vdbe".  Only routines

#define OP_NotNull           109
#define OP_Negative          110
#define OP_And               111
#define OP_Or                112
#define OP_Not               113
#define OP_Concat            114
#define OP_Noop              115

#define OP_Strlen            116
#define OP_Substr            117
#define OP_UserFunc          118
#define OP_UserAgg           119

#define OP_Limit             120

#define OP_MAX               120

/*
** Prototypes for the VDBE interface.  See comments on the implementation
** for a description of what each of these routines does.
*/
Vdbe *sqliteVdbeCreate(sqlite*);
void sqliteVdbeCreateCallback(Vdbe*, int*);

# 2001 September 15
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    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 implements regression tests for SQLite library.  The
# focus of this file is testing the SELECT statement.
#
# $Id: select1.test,v 1.19 2002/02/23 23:45:47 drh Exp $

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

# Try to select on a non-existant table.
#
do_test select1-1.1 {

do_test select1-2.19 {
  set v [catch {execsql {SELECT SUM(min(f1,f2)) FROM test1}} msg]
  lappend v $msg
} {0 44}
do_test select1-2.20 {
  set v [catch {execsql {SELECT SUM(min(f1)) FROM test1}} msg]
  lappend v $msg
} {1 {misuse of aggregate function min()}}

# WHERE clause expressions
#
do_test select1-3.1 {
  set v [catch {execsql {SELECT f1 FROM test1 WHERE f1<11}} msg]
  lappend v $msg
} {0 {}}

do_test select1-3.8 {
  set v [catch {execsql {SELECT f1 FROM test1 WHERE max(f1,f2)!=11}} msg]
  lappend v [lsort $msg]
} {0 {11 33}}
do_test select1-3.9 {
  set v [catch {execsql {SELECT f1 FROM test1 WHERE count(f1,f2)!=11}} msg]
  lappend v $msg
} {1 {misuse of aggregate function count()}}

# ORDER BY expressions
#
do_test select1-4.1 {
  set v [catch {execsql {SELECT f1 FROM test1 ORDER BY f1}} msg]
  lappend v $msg
} {0 {11 33}}
do_test select1-4.2 {
  set v [catch {execsql {SELECT f1 FROM test1 ORDER BY -f1}} msg]
  lappend v $msg
} {0 {33 11}}
do_test select1-4.3 {
  set v [catch {execsql {SELECT f1 FROM test1 ORDER BY min(f1,f2)}} msg]
  lappend v $msg
} {0 {11 33}}
do_test select1-4.4 {
  set v [catch {execsql {SELECT f1 FROM test1 ORDER BY min(f1)}} msg]
  lappend v $msg
} {1 {misuse of aggregate function min()}}
do_test select1-4.5 {
  catchsql {
    SELECT f1 FROM test1 ORDER BY 8.4;
  }
} {1 {ORDER BY expressions should not be constant}}

# ORDER BY ignored on an aggregate query

<li>Change the name of the sanity_check PRAGMA to <b>integrity_check</b>
    and make it available in all compiles.</li>
<li>SELECT min() or max() of an indexed column with no WHERE or GROUP BY
    clause is handled as a special case which avoids a complete table scan.</li>
<li>Automatically generated ROWIDs are now sequential.</li>
<li>Do not allow dot-commands of the command-line shell to occur in the
    middle of a real SQL command.</li>
<li>Modifications to the "lemon" parser generator so that the parser tables
    are 4 times smaller.</li>
<li>Added support for user-defined functions implemented in C.</li>
}

chng {2002 Feb 18 (2.3.3)} {
<li>Allow identifiers to be quoted in square brackets, for compatibility
    with MS-Access.</li>
<li>Added support for sub-queries in the FROM clause of a SELECT.</li>
<li>More efficient implementation of sqliteFileExists() under Windows.