SQLite

      cd[1] = (void *)pScript;
      rc = DbEvalNextCmd(cd, interp, TCL_OK);
    }
    break;
  }

  /*
  **     $db function NAME [-argcount N] [-deterministic] SCRIPT
  **
  ** Create a new SQL function called NAME.  Whenever that function is
  ** called, invoke SCRIPT to evaluate the function.
  */
  case DB_FUNCTION: {
    int flags = SQLITE_UTF8;
    SqlFunc *pFunc;
    Tcl_Obj *pScript;
    char *zName;
    int nArg = -1;
    int i;
    if( objc<4 ){
      Tcl_WrongNumArgs(interp, 2, objv, "NAME ?SWITCHES? SCRIPT");
      return TCL_ERROR;
    }
    for(i=3; i<(objc-1); i++){
      const char *z = Tcl_GetString(objv[i]);
      int n = strlen30(z);
      if( n>2 && strncmp(z, "-argcount",n)==0 ){
        if( i==(objc-2) ){
          Tcl_AppendResult(interp, "option requires an argument: ", z, 0);
          return TCL_ERROR;
        }
        if( Tcl_GetIntFromObj(interp, objv[i+1], &nArg) ) return TCL_ERROR;
        if( nArg<0 ){
          Tcl_AppendResult(interp, "number of arguments must be non-negative",
                           (char*)0);
          return TCL_ERROR;
        }
        i++;
      }else

      if( n>2 && strncmp(z, "-deterministic",n)==0 ){
        flags |= SQLITE_DETERMINISTIC;
      }else{
        Tcl_AppendResult(interp, "bad option \"", z, 
            "\": must be -argcount or -deterministic", 0
        );
        return TCL_ERROR;
      }
    }

    pScript = objv[objc-1];

    zName = Tcl_GetStringFromObj(objv[2], 0);
    pFunc = findSqlFunc(pDb, zName);
    if( pFunc==0 ) return TCL_ERROR;
    if( pFunc->pScript ){
      Tcl_DecrRefCount(pFunc->pScript);
    }
    pFunc->pScript = pScript;
    Tcl_IncrRefCount(pScript);
    pFunc->useEvalObjv = safeToUseEvalObjv(interp, pScript);
    rc = sqlite3_create_function(pDb->db, zName, nArg, flags,
        pFunc, tclSqlFunc, 0, 0);
    if( rc!=SQLITE_OK ){
      rc = TCL_ERROR;
      Tcl_SetResult(interp, (char *)sqlite3_errmsg(pDb->db), TCL_VOLATILE);
    }
    break;
  }

    }
  }

  sqlite3_result_text(context, Tcl_GetString(pRet), -1, SQLITE_TRANSIENT);
  Tcl_DecrRefCount(pRet);
}

/*
** The implementation of scalar SQL function "test_zeroblob()". This is
** similar to the built-in zeroblob() function, except that it does not
** check that the integer parameter is within range before passing it
** to sqlite3_result_zeroblob().
*/
static void test_zeroblob(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  int nZero = sqlite3_value_int(argv[0]);
  sqlite3_result_zeroblob(context, nZero);
}

static int registerTestFunctions(sqlite3 *db){
  static const struct {
     char *zName;
     signed char nArg;
     unsigned int eTextRep; /* 1: UTF-16.  0: UTF-8 */
     void (*xFunc)(sqlite3_context*,int,sqlite3_value **);
  } aFuncs[] = {
    { "randstr",               2, SQLITE_UTF8, randStr    },
    { "test_destructor",       1, SQLITE_UTF8, test_destructor},
#ifndef SQLITE_OMIT_UTF16
    { "test_destructor16",     1, SQLITE_UTF8, test_destructor16},
    { "hex_to_utf16be",        1, SQLITE_UTF8, testHexToUtf16be},
    { "hex_to_utf16le",        1, SQLITE_UTF8, testHexToUtf16le},
#endif
    { "hex_to_utf8",           1, SQLITE_UTF8, testHexToUtf8},
    { "test_destructor_count", 0, SQLITE_UTF8, test_destructor_count},
    { "test_auxdata",         -1, SQLITE_UTF8, test_auxdata},
    { "test_error",            1, SQLITE_UTF8, test_error},
    { "test_error",            2, SQLITE_UTF8, test_error},
    { "test_eval",             1, SQLITE_UTF8, test_eval},
    { "test_isolation",        2, SQLITE_UTF8, test_isolation},
    { "test_counter",          1, SQLITE_UTF8, counterFunc},
    { "real2hex",              1, SQLITE_UTF8, real2hex},
    { "test_decode",           1, SQLITE_UTF8, test_decode},
    { "test_extract",          2, SQLITE_UTF8, test_extract},
    { "test_zeroblob",  1, SQLITE_UTF8|SQLITE_DETERMINISTIC, test_zeroblob},
  };
  int i;

  for(i=0; i<sizeof(aFuncs)/sizeof(aFuncs[0]); i++){
    sqlite3_create_function(db, aFuncs[i].zName, aFuncs[i].nArg,
        aFuncs[i].eTextRep, 0, aFuncs[i].xFunc, 0, 0);
  }

  pVal = valueNew(db, pCtx);
  if( pVal==0 ){
    rc = SQLITE_NOMEM;
    goto value_from_function_out;
  }

  assert( pCtx->pParse->rc==SQLITE_OK );
  memset(&ctx, 0, sizeof(ctx));
  ctx.pOut = pVal;
  ctx.pFunc = pFunc;
  pFunc->xFunc(&ctx, nVal, apVal);
  if( ctx.isError ){
    rc = ctx.isError;
    sqlite3ErrorMsg(pCtx->pParse, "%s", sqlite3_value_text(pVal));

  }else{
    sqlite3ValueApplyAffinity(pVal, aff, SQLITE_UTF8);
    assert( rc==SQLITE_OK );
    rc = sqlite3VdbeChangeEncoding(pVal, enc);
    if( rc==SQLITE_OK && sqlite3VdbeMemTooBig(pVal) ){
      rc = SQLITE_TOOBIG;
      pCtx->pParse->nErr++;
    }
  }
  pCtx->pParse->rc = rc;

 value_from_function_out:
  if( rc!=SQLITE_OK ){
    pVal = 0;
  }
  if( apVal ){
    for(i=0; i<nVal; i++){

  11 "x = nullif('19', 0) AND y = nullif('4', 0)" {t1y (y=?)}
  12 "x = nullif('4', 0) AND y = nullif('19', 0)" {t1y (y=?)}
} {
  set res "0 0 0 {SEARCH TABLE t1 USING INDEX $idx}"
  do_eqp_test 1.$tn "SELECT * FROM t1 WHERE $where" $res
}

# Test that functions that do not exist - "func()" - do not cause an error.
#
do_catchsql_test 2.1 {
  SELECT * FROM t1 WHERE x = substr('145', 2, 1) AND y = func(1, 2, 3)
} {1 {no such function: func}}
do_catchsql_test 2.2 {
  UPDATE t1 SET y=y+1 WHERE x = substr('145', 2, 1) AND y = func(1, 2, 3)
} {1 {no such function: func}}


# Check that functions that accept zero arguments do not cause problems.
#
proc ret {x} { return $x }

db func det4 -deterministic [list ret 4]
db func nondet4 [list ret 4]
db func det19 -deterministic [list ret 19]
db func nondet19 [list ret 19]

foreach {tn where idx} {
  1 "x = det4() AND y = det19()"     {t1x (x=?)}
  2 "x = det19() AND y = det4()"     {t1y (y=?)}

  3 "x = nondet4() AND y = nondet19()"     {t1y (y=?)}
  4 "x = nondet19() AND y = nondet4()"     {t1y (y=?)}
} {
  set res "0 0 0 {SEARCH TABLE t1 USING INDEX $idx}"
  do_eqp_test 3.$tn "SELECT * FROM t1 WHERE $where" $res
}


execsql { DELETE FROM t1 }

proc throw_error {err} { error $err }
db func error -deterministic throw_error
do_catchsql_test 4.1 {
  SELECT * FROM t1 WHERE x = error('error one') AND y = 4;
} {1 {error one}}

do_catchsql_test 4.2 {
  SELECT * FROM t1 WHERE x = zeroblob(2000000000) AND y = 4;
} {1 {string or blob too big}}

sqlite3_limit db SQLITE_LIMIT_LENGTH 1000000
proc dstr {} { return [string repeat x 1100000] }
db func dstr -deterministic dstr
do_catchsql_test 4.3 {
  SELECT * FROM t1 WHERE x = dstr() AND y = 11;
} {1 {string or blob too big}}

do_catchsql_test 4.4 {
  SELECT * FROM t1 WHERE x = test_zeroblob(1100000) AND y = 4;
} {1 {string or blob too big}}


finish_test

  CREATE TABLE x1(a INTEGER PRIMARY KEY, b);
}
do_faultsim_test 7.2 -faults oom* -body {
  execsql { SELECT * FROM x1 WHERE a = (SELECT 1) }
} -test {
  faultsim_test_result [list 0 {}]
}

reset_db

proc isqrt {i} { expr { int(sqrt($i)) } }
db func isqrt isqrt

do_execsql_test 8.0 {
  PRAGMA encoding = 'utf-16';
  CREATE TABLE x2(x TEXT, y TEXT);
  WITH data(i) AS (
    SELECT 1 UNION ALL SELECT i+1 FROM data
  )
  INSERT INTO x2 SELECT isqrt(i), isqrt(i) FROM data LIMIT 400;
  CREATE INDEX x2x ON x2(x);
  CREATE INDEX x2y ON x2(y);
  ANALYZE;
  DELETE FROM x2;
}

proc str {a} { return $a }
db func str -deterministic str

do_faultsim_test 8 -faults oom* -body {
  execsql { SELECT * FROM x2 WHERE x = str('19') AND y = str('4') }
} -test {
  faultsim_test_result [list 0 {}]
}


finish_test

do_test tcl-1.14 {
  set v [catch {db eval} msg]
  lappend v $msg
} {1 {wrong # args: should be "db eval SQL ?ARRAY-NAME? ?SCRIPT?"}}
do_test tcl-1.15 {
  set v [catch {db function} msg]
  lappend v $msg
} {1 {wrong # args: should be "db function NAME ?SWITCHES? SCRIPT"}}
do_test tcl-1.16 {
  set v [catch {db last_insert_rowid xyz} msg]
  lappend v $msg
} {1 {wrong # args: should be "db last_insert_rowid "}}
do_test tcl-1.17 {
  set v [catch {db rekey} msg]
  lappend v $msg