adodb-db2.inc.php

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<?php
/*
  V5.19  23-Apr-2014  (c) 2000-2012 (jlim#natsoft.com). All rights reserved.

  This is a version of the ADODB driver for DB2.  It uses the 'ibm_db2' PECL extension
  for PHP (http://pecl.php.net/package/ibm_db2), which in turn requires DB2 V8.2.2 or
  higher.

  Originally tested with PHP 5.1.1 and Apache 2.0.55 on Windows XP SP2.
  More recently tested with PHP 5.1.2 and Apache 2.0.55 on Windows XP SP2.

  This file was ported from "adodb-odbc.inc.php" by Larry Menard, "larry.menard#rogers.com".
  I ripped out what I believed to be a lot of redundant or obsolete code, but there are
  probably still some remnants of the ODBC support in this file; I'm relying on reviewers
  of this code to point out any other things that can be removed.
*/

// security - hide paths
if (!defined('ADODB_DIR')) die();

  define("_ADODB_DB2_LAYER", 2 );

/*--------------------------------------------------------------------------------------
--------------------------------------------------------------------------------------*/





class ADODB_db2 extends ADOConnection {
    var $databaseType = "db2";
    var $fmtDate = "'Y-m-d'";
    var $concat_operator = '||';

    var $sysTime = 'CURRENT TIME';
    var $sysDate = 'CURRENT DATE';
    var $sysTimeStamp = 'CURRENT TIMESTAMP';

    var $fmtTimeStamp = "'Y-m-d H:i:s'";
    var $replaceQuote = "''"; // string to use to replace quotes
    var $dataProvider = "db2";
    var $hasAffectedRows = true;

    var $binmode = DB2_BINARY;

    var $useFetchArray = false; // setting this to true will make array elements in FETCH_ASSOC mode case-sensitive
                                // breaking backward-compat
    var $_bindInputArray = false;
    var $_genIDSQL = "VALUES NEXTVAL FOR %s";
    var $_genSeqSQL = "CREATE SEQUENCE %s START WITH %s NO MAXVALUE NO CYCLE";
    var $_dropSeqSQL = "DROP SEQUENCE %s";
    var $_autocommit = true;
    var $_haserrorfunctions = true;
    var $_lastAffectedRows = 0;
    var $uCaseTables = true; // for meta* functions, uppercase table names
    var $hasInsertID = true;


    function _insertid()
    {
        return ADOConnection::GetOne('VALUES IDENTITY_VAL_LOCAL()');
    }

    function ADODB_db2()
    {
        $this->_haserrorfunctions = ADODB_PHPVER >= 0x4050;
    }

        // returns true or false
    function _connect($argDSN, $argUsername, $argPassword, $argDatabasename)
    {
        global $php_errormsg;

        if (!function_exists('db2_connect')) {
            ADOConnection::outp("Warning: The old ODBC based DB2 driver has been renamed 'odbc_db2'. This ADOdb driver calls PHP's native db2 extension which is not installed.");
            return null;
        }
        // This needs to be set before the connect().
        // Replaces the odbc_binmode() call that was in Execute()
        ini_set('ibm_db2.binmode', $this->binmode);

        if ($argDatabasename && empty($argDSN)) {

            if (stripos($argDatabasename,'UID=') && stripos($argDatabasename,'PWD=')) $this->_connectionID = db2_connect($argDatabasename,null,null);
            else $this->_connectionID = db2_connect($argDatabasename,$argUsername,$argPassword);
        } else {
            if ($argDatabasename) $schema = $argDatabasename;
            if (stripos($argDSN,'UID=') && stripos($argDSN,'PWD=')) $this->_connectionID = db2_connect($argDSN,null,null);
            else $this->_connectionID = db2_connect($argDSN,$argUsername,$argPassword);
        }
        if (isset($php_errormsg)) $php_errormsg = '';

        // For db2_connect(), there is an optional 4th arg.  If present, it must be
        // an array of valid options.  So far, we don't use them.

        $this->_errorMsg = @db2_conn_errormsg();
        if (isset($this->connectStmt)) $this->Execute($this->connectStmt);

        if ($this->_connectionID && isset($schema)) $this->Execute("SET SCHEMA=$schema");
        return $this->_connectionID != false;
    }

    // returns true or false
    function _pconnect($argDSN, $argUsername, $argPassword, $argDatabasename)
    {
        global $php_errormsg;

        if (!function_exists('db2_connect')) return null;

        // This needs to be set before the connect().
        // Replaces the odbc_binmode() call that was in Execute()
        ini_set('ibm_db2.binmode', $this->binmode);

        if (isset($php_errormsg)) $php_errormsg = '';
        $this->_errorMsg = isset($php_errormsg) ? $php_errormsg : '';

        if ($argDatabasename && empty($argDSN)) {

            if (stripos($argDatabasename,'UID=') && stripos($argDatabasename,'PWD=')) $this->_connectionID = db2_pconnect($argDatabasename,null,null);
            else $this->_connectionID = db2_pconnect($argDatabasename,$argUsername,$argPassword);
        } else {
            if ($argDatabasename) $schema = $argDatabasename;
            if (stripos($argDSN,'UID=') && stripos($argDSN,'PWD=')) $this->_connectionID = db2_pconnect($argDSN,null,null);
            else $this->_connectionID = db2_pconnect($argDSN,$argUsername,$argPassword);
        }
        if (isset($php_errormsg)) $php_errormsg = '';

        $this->_errorMsg = @db2_conn_errormsg();
        if ($this->_connectionID && $this->autoRollback) @db2_rollback($this->_connectionID);
        if (isset($this->connectStmt)) $this->Execute($this->connectStmt);

        if ($this->_connectionID && isset($schema)) $this->Execute("SET SCHEMA=$schema");
        return $this->_connectionID != false;
    }

    // format and return date string in database timestamp format
    function DBTimeStamp($ts)
    {
        if (empty($ts) && $ts !== 0) return 'null';
        if (is_string($ts)) $ts = ADORecordSet::UnixTimeStamp($ts);
        return 'TO_DATE('.adodb_date($this->fmtTimeStamp,$ts).",'YYYY-MM-DD HH24:MI:SS')";
    }

    // Format date column in sql string given an input format that understands Y M D
    function SQLDate($fmt, $col=false)
    {
    // use right() and replace() ?
        if (!$col) $col = $this->sysDate;

        /* use TO_CHAR() if $fmt is TO_CHAR() allowed fmt */
        if ($fmt== 'Y-m-d H:i:s')
            return 'TO_CHAR('.$col.", 'YYYY-MM-DD HH24:MI:SS')";

        $s = '';

        $len = strlen($fmt);
        for ($i=0; $i < $len; $i++) {
            if ($s) $s .= $this->concat_operator;
            $ch = $fmt[$i];
            switch($ch) {
            case 'Y':
            case 'y':
                if ($len==1) return "year($col)";
                $s .= "char(year($col))";
                break;
            case 'M':
                if ($len==1) return "monthname($col)";
                $s .= "substr(monthname($col),1,3)";
                break;
            case 'm':
                if ($len==1) return "month($col)";
                $s .= "right(digits(month($col)),2)";
                break;
            case 'D':
            case 'd':
                if ($len==1) return "day($col)";
                $s .= "right(digits(day($col)),2)";
                break;
            case 'H':
            case 'h':
                if ($len==1) return "hour($col)";
                if ($col != $this->sysDate) $s .= "right(digits(hour($col)),2)";
                else $s .= "''";
                break;
            case 'i':
            case 'I':
                if ($len==1) return "minute($col)";
                if ($col != $this->sysDate)
                    $s .= "right(digits(minute($col)),2)";
                    else $s .= "''";
                break;
            case 'S':
            case 's':
                if ($len==1) return "second($col)";
                if ($col != $this->sysDate)
                    $s .= "right(digits(second($col)),2)";
                else $s .= "''";
                break;
            default:
                if ($ch == '\\') {
                    $i++;
                    $ch = substr($fmt,$i,1);
                }
                $s .= $this->qstr($ch);
            }
        }
        return $s;
    }


    function ServerInfo()
    {
        $row = $this->GetRow("SELECT service_level, fixpack_num FROM TABLE(sysproc.env_get_inst_info())
            as INSTANCEINFO");


        if ($row) {
            $info['version'] = $row[0].':'.$row[1];
            $info['fixpack'] = $row[1];
            $info['description'] = '';
        } else {
            return ADOConnection::ServerInfo();
        }

        return $info;
    }

    function CreateSequence($seqname='adodbseq',$start=1)
    {
        if (empty($this->_genSeqSQL)) return false;
        $ok = $this->Execute(sprintf($this->_genSeqSQL,$seqname,$start));
        if (!$ok) return false;
        return true;
    }

    function DropSequence($seqname)
    {
        if (empty($this->_dropSeqSQL)) return false;
        return $this->Execute(sprintf($this->_dropSeqSQL,$seqname));
    }

    function SelectLimit($sql,$nrows=-1,$offset=-1,$inputArr=false)
    {
        $nrows = (integer) $nrows;
        if ($offset <= 0) {
        // could also use " OPTIMIZE FOR $nrows ROWS "
            if ($nrows >= 0) $sql .=  " FETCH FIRST $nrows ROWS ONLY ";
            $rs = $this->Execute($sql,$inputArr);
        } else {
            if ($offset > 0 && $nrows < 0);
            else {
                $nrows += $offset;
                $sql .=  " FETCH FIRST $nrows ROWS ONLY ";
            }
            $rs = ADOConnection::SelectLimit($sql,-1,$offset,$inputArr);
        }

        return $rs;
    }

    /*
        This algorithm is not very efficient, but works even if table locking
        is not available.

        Will return false if unable to generate an ID after $MAXLOOPS attempts.
    */
    function GenID($seq='adodbseq',$start=1)
    {
        // if you have to modify the parameter below, your database is overloaded,
        // or you need to implement generation of id's yourself!
                $num = $this->GetOne("VALUES NEXTVAL FOR $seq");
                return $num;
    }


    function ErrorMsg()
    {
        if ($this->_haserrorfunctions) {
            if ($this->_errorMsg !== false) return $this->_errorMsg;
            if (empty($this->_connectionID)) return @db2_conn_errormsg();
            return @db2_conn_errormsg($this->_connectionID);
        } else return ADOConnection::ErrorMsg();
    }

    function ErrorNo()
    {

        if ($this->_haserrorfunctions) {
            if ($this->_errorCode !== false) {
                // bug in 4.0.6, error number can be corrupted string (should be 6 digits)
                return (strlen($this->_errorCode)<=2) ? 0 : $this->_errorCode;
            }

            if (empty($this->_connectionID)) $e = @db2_conn_error();
            else $e = @db2_conn_error($this->_connectionID);

             // bug in 4.0.6, error number can be corrupted string (should be 6 digits)
             // so we check and patch
            if (strlen($e)<=2) return 0;
            return $e;
        } else return ADOConnection::ErrorNo();
    }



    function BeginTrans()
    {
        if (!$this->hasTransactions) return false;
        if ($this->transOff) return true;
        $this->transCnt += 1;
        $this->_autocommit = false;
        return db2_autocommit($this->_connectionID,false);
    }

    function CommitTrans($ok=true)
    {
        if ($this->transOff) return true;
        if (!$ok) return $this->RollbackTrans();
        if ($this->transCnt) $this->transCnt -= 1;
        $this->_autocommit = true;
        $ret = db2_commit($this->_connectionID);
        db2_autocommit($this->_connectionID,true);
        return $ret;
    }

    function RollbackTrans()
    {
        if ($this->transOff) return true;
        if ($this->transCnt) $this->transCnt -= 1;
        $this->_autocommit = true;
        $ret = db2_rollback($this->_connectionID);
        db2_autocommit($this->_connectionID,true);
        return $ret;
    }

    function MetaPrimaryKeys($table)
    {
    global $ADODB_FETCH_MODE;

        if ($this->uCaseTables) $table = strtoupper($table);
        $schema = '';
        $this->_findschema($table,$schema);

        $savem = $ADODB_FETCH_MODE;
        $ADODB_FETCH_MODE = ADODB_FETCH_NUM;
        $qid = @db2_primarykeys($this->_connectionID,'',$schema,$table);

        if (!$qid) {
            $ADODB_FETCH_MODE = $savem;
            return false;
        }
        $rs = new ADORecordSet_db2($qid);
        $ADODB_FETCH_MODE = $savem;

        if (!$rs) return false;

        $arr = $rs->GetArray();
        $rs->Close();
        $arr2 = array();
        for ($i=0; $i < sizeof($arr); $i++) {
            if ($arr[$i][3]) $arr2[] = $arr[$i][3];
        }
        return $arr2;
    }

    function MetaForeignKeys($table, $owner = FALSE, $upper = FALSE, $asociative = FALSE )
    {
    global $ADODB_FETCH_MODE;

        if ($this->uCaseTables) $table = strtoupper($table);
        $schema = '';
        $this->_findschema($table,$schema);

        $savem = $ADODB_FETCH_MODE;
        $ADODB_FETCH_MODE = ADODB_FETCH_NUM;
        $qid = @db2_foreign_keys($this->_connectionID,'',$schema,$table);
        if (!$qid) {
            $ADODB_FETCH_MODE = $savem;
            return false;
        }
        $rs = new ADORecordSet_db2($qid);

        $ADODB_FETCH_MODE = $savem;
        /*
        $rs->fields indices
        0 PKTABLE_CAT
        1 PKTABLE_SCHEM
        2 PKTABLE_NAME
        3 PKCOLUMN_NAME
        4 FKTABLE_CAT
        5 FKTABLE_SCHEM
        6 FKTABLE_NAME
        7 FKCOLUMN_NAME
        */
        if (!$rs) return false;

        $foreign_keys = array();
        while (!$rs->EOF) {
            if (strtoupper(trim($rs->fields[2])) == $table && (!$schema || strtoupper($rs->fields[1]) == $schema)) {
                if (!is_array($foreign_keys[$rs->fields[5].'.'.$rs->fields[6]]))
                    $foreign_keys[$rs->fields[5].'.'.$rs->fields[6]] = array();
                $foreign_keys[$rs->fields[5].'.'.$rs->fields[6]][$rs->fields[7]] = $rs->fields[3];
            }
            $rs->MoveNext();
        }

        $rs->Close();
        return $foreign_key;
    }


    function MetaTables($ttype=false,$schema=false)
    {
    global $ADODB_FETCH_MODE;

        $savem = $ADODB_FETCH_MODE;
        $ADODB_FETCH_MODE = ADODB_FETCH_NUM;
        $qid = db2_tables($this->_connectionID);

        $rs = new ADORecordSet_db2($qid);

        $ADODB_FETCH_MODE = $savem;
        if (!$rs) {
            $false = false;
            return $false;
        }

        $arr = $rs->GetArray();
        $rs->Close();
        $arr2 = array();

        if ($ttype) {
            $isview = strncmp($ttype,'V',1) === 0;
        }
        for ($i=0; $i < sizeof($arr); $i++) {
            if (!$arr[$i][2]) continue;
            $type = $arr[$i][3];
            $owner = $arr[$i][1];
            $schemaval = ($schema) ? $arr[$i][1].'.' : '';
            if ($ttype) {
                if ($isview) {
                    if (strncmp($type,'V',1) === 0) $arr2[] = $schemaval.$arr[$i][2];
                } else if (strncmp($owner,'SYS',3) !== 0) $arr2[] = $schemaval.$arr[$i][2];
            } else if (strncmp($owner,'SYS',3) !== 0) $arr2[] = $schemaval.$arr[$i][2];
        }
        return $arr2;
    }

/*
See http://msdn.microsoft.com/library/default.asp?url=/library/en-us/db2/htm/db2datetime_data_type_changes.asp
/ SQL data type codes /
#define SQL_UNKNOWN_TYPE    0
#define SQL_CHAR            1
#define SQL_NUMERIC      2
#define SQL_DECIMAL      3
#define SQL_INTEGER      4
#define SQL_SMALLINT        5
#define SQL_FLOAT          6
#define SQL_REAL            7
#define SQL_DOUBLE        8
#if (DB2VER >= 0x0300)
#define SQL_DATETIME        9
#endif
#define SQL_VARCHAR     12


/ One-parameter shortcuts for date/time data types /
#if (DB2VER >= 0x0300)
#define SQL_TYPE_DATE     91
#define SQL_TYPE_TIME     92
#define SQL_TYPE_TIMESTAMP 93

#define SQL_UNICODE                             (-95)
#define SQL_UNICODE_VARCHAR                     (-96)
#define SQL_UNICODE_LONGVARCHAR                 (-97)
*/
    function DB2Types($t)
    {
        switch ((integer)$t) {
        case 1:
        case 12:
        case 0:
        case -95:
        case -96:
            return 'C';
        case -97:
        case -1: //text
            return 'X';
        case -4: //image
            return 'B';

        case 9:
        case 91:
            return 'D';

        case 10:
        case 11:
        case 92:
        case 93:
            return 'T';

        case 4:
        case 5:
        case -6:
            return 'I';

        case -11: // uniqidentifier
            return 'R';
        case -7: //bit
            return 'L';

        default:
            return 'N';
        }
    }

    function MetaColumns($table, $normalize=true)
    {
    global $ADODB_FETCH_MODE;

        $false = false;
        if ($this->uCaseTables) $table = strtoupper($table);
        $schema = '';
        $this->_findschema($table,$schema);

        $savem = $ADODB_FETCH_MODE;
        $ADODB_FETCH_MODE = ADODB_FETCH_NUM;

            $colname = "%";
            $qid = db2_columns($this->_connectionID, "", $schema, $table, $colname);
        if (empty($qid)) return $false;

        $rs = new ADORecordSet_db2($qid);
        $ADODB_FETCH_MODE = $savem;

        if (!$rs) return $false;
        $rs->_fetch();

        $retarr = array();

        /*
        $rs->fields indices
        0 TABLE_QUALIFIER
        1 TABLE_SCHEM
        2 TABLE_NAME
        3 COLUMN_NAME
        4 DATA_TYPE
        5 TYPE_NAME
        6 PRECISION
        7 LENGTH
        8 SCALE
        9 RADIX
        10 NULLABLE
        11 REMARKS
        */
        while (!$rs->EOF) {
            if (strtoupper(trim($rs->fields[2])) == $table && (!$schema || strtoupper($rs->fields[1]) == $schema)) {
                $fld = new ADOFieldObject();
                $fld->name = $rs->fields[3];
                $fld->type = $this->DB2Types($rs->fields[4]);

                // ref: http://msdn.microsoft.com/library/default.asp?url=/archive/en-us/dnaraccgen/html/msdn_odk.asp
                // access uses precision to store length for char/varchar
                if ($fld->type == 'C' or $fld->type == 'X') {
                    if ($rs->fields[4] <= -95) // UNICODE
                        $fld->max_length = $rs->fields[7]/2;
                    else
                        $fld->max_length = $rs->fields[7];
                } else
                    $fld->max_length = $rs->fields[7];
                $fld->not_null = !empty($rs->fields[10]);
                $fld->scale = $rs->fields[8];
                $fld->primary_key = false;
                $retarr[strtoupper($fld->name)] = $fld;
            } else if (sizeof($retarr)>0)
                break;
            $rs->MoveNext();
        }
        $rs->Close();
        if (empty($retarr)) $retarr = false;

          $qid = db2_primary_keys($this->_connectionID, "", $schema, $table);
        if (empty($qid)) return $false;

        $rs = new ADORecordSet_db2($qid);
        $ADODB_FETCH_MODE = $savem;

        if (!$rs) return $retarr;
        $rs->_fetch();

        /*
        $rs->fields indices
        0 TABLE_CAT
        1 TABLE_SCHEM
        2 TABLE_NAME
        3 COLUMN_NAME
        4 KEY_SEQ
        5 PK_NAME
        */
        while (!$rs->EOF) {
            if (strtoupper(trim($rs->fields[2])) == $table && (!$schema || strtoupper($rs->fields[1]) == $schema)) {
                $retarr[strtoupper($rs->fields[3])]->primary_key = true;
            } else if (sizeof($retarr)>0)
                break;
            $rs->MoveNext();
        }
        $rs->Close();

        if (empty($retarr)) $retarr = false;
        return $retarr;
    }


    function Prepare($sql)
    {
        if (! $this->_bindInputArray) return $sql; // no binding
        $stmt = db2_prepare($this->_connectionID,$sql);
        if (!$stmt) {
            // we don't know whether db2 driver is parsing prepared stmts, so just return sql
            return $sql;
        }
        return array($sql,$stmt,false);
    }

    /* returns queryID or false */
    function _query($sql,$inputarr=false)
    {
    GLOBAL $php_errormsg;
        if (isset($php_errormsg)) $php_errormsg = '';
        $this->_error = '';

        if ($inputarr) {
            if (is_array($sql)) {
                $stmtid = $sql[1];
            } else {
                $stmtid = db2_prepare($this->_connectionID,$sql);

                if ($stmtid == false) {
                    $this->_errorMsg = isset($php_errormsg) ? $php_errormsg : '';
                    return false;
                }
            }

            if (! db2_execute($stmtid,$inputarr)) {
                if ($this->_haserrorfunctions) {
                    $this->_errorMsg = db2_stmt_errormsg();
                    $this->_errorCode = db2_stmt_error();
                }
                return false;
            }

        } else if (is_array($sql)) {
            $stmtid = $sql[1];
            if (!db2_execute($stmtid)) {
                if ($this->_haserrorfunctions) {
                    $this->_errorMsg = db2_stmt_errormsg();
                    $this->_errorCode = db2_stmt_error();
                }
                return false;
            }
        } else
            $stmtid = @db2_exec($this->_connectionID,$sql);

        $this->_lastAffectedRows = 0;
        if ($stmtid) {
            if (@db2_num_fields($stmtid) == 0) {
                $this->_lastAffectedRows = db2_num_rows($stmtid);
                $stmtid = true;
            } else {
                $this->_lastAffectedRows = 0;
            }

            if ($this->_haserrorfunctions) {
                $this->_errorMsg = '';
                $this->_errorCode = 0;
            } else
                $this->_errorMsg = isset($php_errormsg) ? $php_errormsg : '';
        } else {
            if ($this->_haserrorfunctions) {
                $this->_errorMsg = db2_stmt_errormsg();
                $this->_errorCode = db2_stmt_error();
            } else
                $this->_errorMsg = isset($php_errormsg) ? $php_errormsg : '';

        }
        return $stmtid;
    }

    /*
        Insert a null into the blob field of the table first.
        Then use UpdateBlob to store the blob.

        Usage:

        $conn->Execute('INSERT INTO blobtable (id, blobcol) VALUES (1, null)');
        $conn->UpdateBlob('blobtable','blobcol',$blob,'id=1');
    */
    function UpdateBlob($table,$column,$val,$where,$blobtype='BLOB')
    {
        return $this->Execute("UPDATE $table SET $column=? WHERE $where",array($val)) != false;
    }

    // returns true or false
    function _close()
    {
        $ret = @db2_close($this->_connectionID);
        $this->_connectionID = false;
        return $ret;
    }

    function _affectedrows()
    {
        return $this->_lastAffectedRows;
    }

}

/*--------------------------------------------------------------------------------------
     Class Name: Recordset
--------------------------------------------------------------------------------------*/

class ADORecordSet_db2 extends ADORecordSet {

    var $bind = false;
    var $databaseType = "db2";
    var $dataProvider = "db2";
    var $useFetchArray;

    function ADORecordSet_db2($id,$mode=false)
    {
        if ($mode === false) {
            global $ADODB_FETCH_MODE;
            $mode = $ADODB_FETCH_MODE;
        }
        $this->fetchMode = $mode;

        $this->_queryID = $id;
    }


    // returns the field object
    function FetchField($offset = -1)
    {
        $o= new ADOFieldObject();
        $o->name = @db2_field_name($this->_queryID,$offset);
        $o->type = @db2_field_type($this->_queryID,$offset);
        $o->max_length = db2_field_width($this->_queryID,$offset);
        if (ADODB_ASSOC_CASE == 0) $o->name = strtolower($o->name);
        else if (ADODB_ASSOC_CASE == 1) $o->name = strtoupper($o->name);
        return $o;
    }

    /* Use associative array to get fields array */
    function Fields($colname)
    {
        if ($this->fetchMode & ADODB_FETCH_ASSOC) return $this->fields[$colname];
        if (!$this->bind) {
            $this->bind = array();
            for ($i=0; $i < $this->_numOfFields; $i++) {
                $o = $this->FetchField($i);
                $this->bind[strtoupper($o->name)] = $i;
            }
        }

         return $this->fields[$this->bind[strtoupper($colname)]];
    }


    function _initrs()
    {
    global $ADODB_COUNTRECS;
        $this->_numOfRows = ($ADODB_COUNTRECS) ? @db2_num_rows($this->_queryID) : -1;
        $this->_numOfFields = @db2_num_fields($this->_queryID);
        // some silly drivers such as db2 as/400 and intersystems cache return _numOfRows = 0
        if ($this->_numOfRows == 0) $this->_numOfRows = -1;
    }

    function _seek($row)
    {
        return false;
    }

    // speed up SelectLimit() by switching to ADODB_FETCH_NUM as ADODB_FETCH_ASSOC is emulated
    function GetArrayLimit($nrows,$offset=-1)
    {
        if ($offset <= 0) {
            $rs = $this->GetArray($nrows);
            return $rs;
        }
        $savem = $this->fetchMode;
        $this->fetchMode = ADODB_FETCH_NUM;
        $this->Move($offset);
        $this->fetchMode = $savem;

        if ($this->fetchMode & ADODB_FETCH_ASSOC) {
            $this->fields = $this->GetRowAssoc(ADODB_ASSOC_CASE);
        }

        $results = array();
        $cnt = 0;
        while (!$this->EOF && $nrows != $cnt) {
            $results[$cnt++] = $this->fields;
            $this->MoveNext();
        }

        return $results;
    }


    function MoveNext()
    {
        if ($this->_numOfRows != 0 && !$this->EOF) {
            $this->_currentRow++;

            $this->fields = @db2_fetch_array($this->_queryID);
            if ($this->fields) {
                if ($this->fetchMode & ADODB_FETCH_ASSOC) {
                    $this->fields = $this->GetRowAssoc(ADODB_ASSOC_CASE);
                }
                return true;
            }
        }
        $this->fields = false;
        $this->EOF = true;
        return false;
    }

    function _fetch()
    {

        $this->fields = db2_fetch_array($this->_queryID);
        if ($this->fields) {
            if ($this->fetchMode & ADODB_FETCH_ASSOC) {
                $this->fields = $this->GetRowAssoc(ADODB_ASSOC_CASE);
            }
            return true;
        }
        $this->fields = false;
        return false;
    }

    function _close()
    {
        return @db2_free_result($this->_queryID);
    }

}