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 <?php
 /**
  * Zend Framework
  *
  * LICENSE
  *
  * This source file is subject to the new BSD license that is bundled
  * with this package in the file LICENSE.txt.
  * It is also available through the world-wide-web at this URL:
  * http://framework.zend.com/license/new-bsd
  * If you did not receive a copy of the license and are unable to
  * obtain it through the world-wide-web, please send an email
  * to license@zend.com so we can send you a copy immediately.
  *
  * @category   Zend
  * @package    Zend_Db
  * @subpackage Adapter
  * @copyright  Copyright (c) 2005-2015 Zend Technologies USA Inc. (http://www.zend.com)
  * @license    http://framework.zend.com/license/new-bsd     New BSD License
  * @version    $Id$
  *
  */
 
 /**
  * @see Zend_Db
  */
 // require_once 'Zend/Db.php';
 
 /**
  * @see Zend_Db_Adapter_Abstract
  */
 // require_once 'Zend/Db/Adapter/Abstract.php';
 
 /**
  * @see Zend_Db_Statement_Db2
  */
 // require_once 'Zend/Db/Statement/Db2.php';
 
 
 /**
  * @package    Zend_Db
  * @copyright  Copyright (c) 2005-2015 Zend Technologies USA Inc. (http://www.zend.com)
  * @license    http://framework.zend.com/license/new-bsd     New BSD License
  */
 
 class Zend_Db_Adapter_Db2 extends Zend_Db_Adapter_Abstract
 {
     /**
      * User-provided configuration.
      *
      * Basic keys are:
      *
      * username   => (string)  Connect to the database as this username.
      * password   => (string)  Password associated with the username.
      * host       => (string)  What host to connect to (default 127.0.0.1)
      * dbname     => (string)  The name of the database to user
      * protocol   => (string)  Protocol to use, defaults to "TCPIP"
      * port       => (integer) Port number to use for TCP/IP if protocol is "TCPIP"
      * persistent => (boolean) Set TRUE to use a persistent connection (db2_pconnect)
      * os         => (string)  This should be set to 'i5' if the db is on an os400/i5
      * schema     => (string)  The default schema the connection should use
      *
      * @var array
      */
     protected $_config = array(
         'dbname'       => null,
         'username'     => null,
         'password'     => null,
         'host'         => 'localhost',
         'port'         => '50000',
         'protocol'     => 'TCPIP',
         'persistent'   => false,
         'os'           => null,
         'schema'       => null
     );
 
     /**
      * Execution mode
      *
      * @var int execution flag (DB2_AUTOCOMMIT_ON or DB2_AUTOCOMMIT_OFF)
      */
     protected $_execute_mode = DB2_AUTOCOMMIT_ON;
 
     /**
      * Default class name for a DB statement.
      *
      * @var string
      */
     protected $_defaultStmtClass = 'Zend_Db_Statement_Db2';
     protected $_isI5 = false;
 
     /**
      * Keys are UPPERCASE SQL datatypes or the constants
      * Zend_Db::INT_TYPE, Zend_Db::BIGINT_TYPE, or Zend_Db::FLOAT_TYPE.
      *
      * Values are:
      * 0 = 32-bit integer
      * 1 = 64-bit integer
      * 2 = float or decimal
      *
      * @var array Associative array of datatypes to values 0, 1, or 2.
      */
     protected $_numericDataTypes = array(
         Zend_Db::INT_TYPE    => Zend_Db::INT_TYPE,
         Zend_Db::BIGINT_TYPE => Zend_Db::BIGINT_TYPE,
         Zend_Db::FLOAT_TYPE  => Zend_Db::FLOAT_TYPE,
         'INTEGER'            => Zend_Db::INT_TYPE,
         'SMALLINT'           => Zend_Db::INT_TYPE,
         'BIGINT'             => Zend_Db::BIGINT_TYPE,
         'DECIMAL'            => Zend_Db::FLOAT_TYPE,
         'NUMERIC'            => Zend_Db::FLOAT_TYPE
     );
 
     /**
      * Creates a connection resource.
      *
      * @return void
      */
     protected function _connect()
     {
         if (is_resource($this->_connection)) {
             // connection already exists
             return;
         }
 
         if (!extension_loaded('ibm_db2')) {
             /**
              * @see Zend_Db_Adapter_Db2_Exception
              */
             // require_once 'Zend/Db/Adapter/Db2/Exception.php';
             throw new Zend_Db_Adapter_Db2_Exception('The IBM DB2 extension is required for this adapter but the extension is not loaded');
         }
 
         $this->_determineI5();
         if ($this->_config['persistent']) {
             // use persistent connection
             $conn_func_name = 'db2_pconnect';
         } else {
             // use "normal" connection
             $conn_func_name = 'db2_connect';
         }
 
         if (!isset($this->_config['driver_options']['autocommit'])) {
             // set execution mode
             $this->_config['driver_options']['autocommit'] = &$this->_execute_mode;
         }
 
         if (isset($this->_config['options'][Zend_Db::CASE_FOLDING])) {
             $caseAttrMap = array(
                 Zend_Db::CASE_NATURAL => DB2_CASE_NATURAL,
                 Zend_Db::CASE_UPPER   => DB2_CASE_UPPER,
                 Zend_Db::CASE_LOWER   => DB2_CASE_LOWER
             );
             $this->_config['driver_options']['DB2_ATTR_CASE'] = $caseAttrMap[$this->_config['options'][Zend_Db::CASE_FOLDING]];
         }
 
         if ($this->_isI5 && isset($this->_config['driver_options']['i5_naming'])) {
             if ($this->_config['driver_options']['i5_naming']) {
                 $this->_config['driver_options']['i5_naming'] = DB2_I5_NAMING_ON;
             } else {
                 $this->_config['driver_options']['i5_naming'] = DB2_I5_NAMING_OFF;
             }
         }
 
         if ($this->_config['host'] !== 'localhost' && !$this->_isI5) {
             // if the host isn't localhost, use extended connection params
             $dbname = 'DRIVER={IBM DB2 ODBC DRIVER}' .
                      ';DATABASE=' . $this->_config['dbname'] .
                      ';HOSTNAME=' . $this->_config['host'] .
                      ';PORT='     . $this->_config['port'] .
                      ';PROTOCOL=' . $this->_config['protocol'] .
                      ';UID='      . $this->_config['username'] .
                      ';PWD='      . $this->_config['password'] .';';
             $this->_connection = $conn_func_name(
                 $dbname,
                 null,
                 null,
                 $this->_config['driver_options']
             );
         } else {
             // host is localhost, so use standard connection params
             $this->_connection = $conn_func_name(
                 $this->_config['dbname'],
                 $this->_config['username'],
                 $this->_config['password'],
                 $this->_config['driver_options']
             );
         }
 
         // check the connection
         if (!$this->_connection) {
             /**
              * @see Zend_Db_Adapter_Db2_Exception
              */
             // require_once 'Zend/Db/Adapter/Db2/Exception.php';
             throw new Zend_Db_Adapter_Db2_Exception(db2_conn_errormsg(), db2_conn_error());
         }
     }
 
     /**
      * Test if a connection is active
      *
      * @return boolean
      */
     public function isConnected()
     {
         return ((bool) (is_resource($this->_connection)
                      && get_resource_type($this->_connection) == 'DB2 Connection'));
     }
 
     /**
      * Force the connection to close.
      *
      * @return void
      */
     public function closeConnection()
     {
         if ($this->isConnected()) {
             db2_close($this->_connection);
         }
         $this->_connection = null;
     }
 
     /**
      * Returns an SQL statement for preparation.
      *
      * @param string $sql The SQL statement with placeholders.
      * @return Zend_Db_Statement_Db2
      */
     public function prepare($sql)
     {
         $this->_connect();
         $stmtClass = $this->_defaultStmtClass;
         if (!class_exists($stmtClass)) {
             // require_once 'Zend/Loader.php';
             Zend_Loader::loadClass($stmtClass);
         }
         $stmt = new $stmtClass($this, $sql);
         $stmt->setFetchMode($this->_fetchMode);
         return $stmt;
     }
 
     /**
      * Gets the execution mode
      *
      * @return int the execution mode (DB2_AUTOCOMMIT_ON or DB2_AUTOCOMMIT_OFF)
      */
     public function _getExecuteMode()
     {
         return $this->_execute_mode;
     }
 
     /**
      * @param integer $mode
      * @return void
      */
     public function _setExecuteMode($mode)
     {
         switch ($mode) {
             case DB2_AUTOCOMMIT_OFF:
             case DB2_AUTOCOMMIT_ON:
                 $this->_execute_mode = $mode;
                 db2_autocommit($this->_connection, $mode);
                 break;
             default:
                 /**
                  * @see Zend_Db_Adapter_Db2_Exception
                  */
                 // require_once 'Zend/Db/Adapter/Db2/Exception.php';
                 throw new Zend_Db_Adapter_Db2_Exception("execution mode not supported");
                 break;
         }
     }
 
     /**
      * Quote a raw string.
      *
      * @param string $value     Raw string
      * @return string           Quoted string
      */
     protected function _quote($value)
     {
         if (is_int($value) || is_float($value)) {
             return $value;
         }
         /**
          * Use db2_escape_string() if it is present in the IBM DB2 extension.
          * But some supported versions of PHP do not include this function,
          * so fall back to default quoting in the parent class.
          */
         if (function_exists('db2_escape_string')) {
             return "'" . db2_escape_string($value) . "'";
         }
         return parent::_quote($value);
     }
 
     /**
      * @return string
      */
     public function getQuoteIdentifierSymbol()
     {
         $this->_connect();
         $info = db2_server_info($this->_connection);
         if ($info) {
             $identQuote = $info->IDENTIFIER_QUOTE_CHAR;
         } else {
             // db2_server_info() does not return result on some i5 OS version
             if ($this->_isI5) {
                 $identQuote ="'";
             }
         }
         return $identQuote;
     }
 
     /**
      * Returns a list of the tables in the database.
      * @param string $schema OPTIONAL
      * @return array
      */
     public function listTables($schema = null)
     {
         $this->_connect();
 
         if ($schema === null && $this->_config['schema'] != null) {
             $schema = $this->_config['schema'];
         }
 
         $tables = array();
 
         if (!$this->_isI5) {
             if ($schema) {
                 $stmt = db2_tables($this->_connection, null, $schema);
             } else {
                 $stmt = db2_tables($this->_connection);
             }
             while ($row = db2_fetch_assoc($stmt)) {
                 $tables[] = $row['TABLE_NAME'];
             }
         } else {
             $tables = $this->_i5listTables($schema);
         }
 
         return $tables;
     }
 
 
     /**
      * Returns the column descriptions for a table.
      *
      * The return value is an associative array keyed by the column name,
      * as returned by the RDBMS.
      *
      * The value of each array element is an associative array
      * with the following keys:
      *
      * SCHEMA_NAME      => string; name of database or schema
      * TABLE_NAME       => string;
      * COLUMN_NAME      => string; column name
      * COLUMN_POSITION  => number; ordinal position of column in table
      * DATA_TYPE        => string; SQL datatype name of column
      * DEFAULT          => string; default expression of column, null if none
      * NULLABLE         => boolean; true if column can have nulls
      * LENGTH           => number; length of CHAR/VARCHAR
      * SCALE            => number; scale of NUMERIC/DECIMAL
      * PRECISION        => number; precision of NUMERIC/DECIMAL
      * UNSIGNED         => boolean; unsigned property of an integer type
      *                     DB2 not supports UNSIGNED integer.
      * PRIMARY          => boolean; true if column is part of the primary key
      * PRIMARY_POSITION => integer; position of column in primary key
      * IDENTITY         => integer; true if column is auto-generated with unique values
      *
      * @param string $tableName
      * @param string $schemaName OPTIONAL
      * @return array
      */
     public function describeTable($tableName, $schemaName = null)
     {
         // Ensure the connection is made so that _isI5 is set
         $this->_connect();
 
         if ($schemaName === null && $this->_config['schema'] != null) {
             $schemaName = $this->_config['schema'];
         }
 
         if (!$this->_isI5) {
 
             $sql = "SELECT DISTINCT c.tabschema, c.tabname, c.colname, c.colno,
                 c.typename, c.default, c.nulls, c.length, c.scale,
                 c.identity, tc.type AS tabconsttype, k.colseq
                 FROM syscat.columns c
                 LEFT JOIN (syscat.keycoluse k JOIN syscat.tabconst tc
                 ON (k.tabschema = tc.tabschema
                     AND k.tabname = tc.tabname
                     AND tc.type = 'P'))
                 ON (c.tabschema = k.tabschema
                     AND c.tabname = k.tabname
                     AND c.colname = k.colname)
                 WHERE "
                 . $this->quoteInto('UPPER(c.tabname) = UPPER(?)', $tableName);
 
             if ($schemaName) {
                $sql .= $this->quoteInto(' AND UPPER(c.tabschema) = UPPER(?)', $schemaName);
             }
 
             $sql .= " ORDER BY c.colno";
 
         } else {
 
             // DB2 On I5 specific query
             $sql = "SELECT DISTINCT C.TABLE_SCHEMA, C.TABLE_NAME, C.COLUMN_NAME, C.ORDINAL_POSITION,
                 C.DATA_TYPE, C.COLUMN_DEFAULT, C.NULLS ,C.LENGTH, C.SCALE, LEFT(C.IDENTITY,1),
                 LEFT(tc.TYPE, 1) AS tabconsttype, k.COLSEQ
                 FROM QSYS2.SYSCOLUMNS C
                 LEFT JOIN (QSYS2.syskeycst k JOIN QSYS2.SYSCST tc
                     ON (k.TABLE_SCHEMA = tc.TABLE_SCHEMA
                       AND k.TABLE_NAME = tc.TABLE_NAME
                       AND LEFT(tc.type,1) = 'P'))
                     ON (C.TABLE_SCHEMA = k.TABLE_SCHEMA
                        AND C.TABLE_NAME = k.TABLE_NAME
                        AND C.COLUMN_NAME = k.COLUMN_NAME)
                 WHERE "
                 . $this->quoteInto('UPPER(C.TABLE_NAME) = UPPER(?)', $tableName);
 
             if ($schemaName) {
                 $sql .= $this->quoteInto(' AND UPPER(C.TABLE_SCHEMA) = UPPER(?)', $schemaName);
             }
 
             $sql .= " ORDER BY C.ORDINAL_POSITION FOR FETCH ONLY";
         }
 
         $desc = array();
         $stmt = $this->query($sql);
 
         /**
          * To avoid case issues, fetch using FETCH_NUM
          */
         $result = $stmt->fetchAll(Zend_Db::FETCH_NUM);
 
         /**
          * The ordering of columns is defined by the query so we can map
          * to variables to improve readability
          */
         $tabschema      = 0;
         $tabname        = 1;
         $colname        = 2;
         $colno          = 3;
         $typename       = 4;
         $default        = 5;
         $nulls          = 6;
         $length         = 7;
         $scale          = 8;
         $identityCol    = 9;
         $tabconstType   = 10;
         $colseq         = 11;
 
         foreach ($result as $key => $row) {
             list ($primary, $primaryPosition, $identity) = array(false, null, false);
             if ($row[$tabconstType] == 'P') {
                 $primary = true;
                 $primaryPosition = $row[$colseq];
             }
             /**
              * In IBM DB2, an column can be IDENTITY
              * even if it is not part of the PRIMARY KEY.
              */
             if ($row[$identityCol] == 'Y') {
                 $identity = true;
             }
 
             // only colname needs to be case adjusted
             $desc[$this->foldCase($row[$colname])] = array(
                 'SCHEMA_NAME'      => $this->foldCase($row[$tabschema]),
                 'TABLE_NAME'       => $this->foldCase($row[$tabname]),
                 'COLUMN_NAME'      => $this->foldCase($row[$colname]),
                 'COLUMN_POSITION'  => (!$this->_isI5) ? $row[$colno]+1 : $row[$colno],
                 'DATA_TYPE'        => $row[$typename],
                 'DEFAULT'          => $row[$default],
                 'NULLABLE'         => (bool) ($row[$nulls] == 'Y'),
                 'LENGTH'           => $row[$length],
                 'SCALE'            => $row[$scale],
                 'PRECISION'        => ($row[$typename] == 'DECIMAL' ? $row[$length] : 0),
                 'UNSIGNED'         => false,
                 'PRIMARY'          => $primary,
                 'PRIMARY_POSITION' => $primaryPosition,
                 'IDENTITY'         => $identity
             );
         }
 
         return $desc;
     }
 
     /**
      * Return the most recent value from the specified sequence in the database.
      * This is supported only on RDBMS brands that support sequences
      * (e.g. Oracle, PostgreSQL, DB2).  Other RDBMS brands return null.
      *
      * @param string $sequenceName
      * @return string
      */
     public function lastSequenceId($sequenceName)
     {
         $this->_connect();
 
         if (!$this->_isI5) {
             $quotedSequenceName = $this->quoteIdentifier($sequenceName, true);
             $sql = 'SELECT PREVVAL FOR ' . $quotedSequenceName . ' AS VAL FROM SYSIBM.SYSDUMMY1';
         } else {
             $quotedSequenceName = $sequenceName;
             $sql = 'SELECT PREVVAL FOR ' . $this->quoteIdentifier($sequenceName, true) . ' AS VAL FROM QSYS2.QSQPTABL';
         }
 
         $value = $this->fetchOne($sql);
         return (string) $value;
     }
 
     /**
      * Generate a new value from the specified sequence in the database, and return it.
      * This is supported only on RDBMS brands that support sequences
      * (e.g. Oracle, PostgreSQL, DB2).  Other RDBMS brands return null.
      *
      * @param string $sequenceName
      * @return string
      */
     public function nextSequenceId($sequenceName)
     {
         $this->_connect();
         $sql = 'SELECT NEXTVAL FOR '.$this->quoteIdentifier($sequenceName, true).' AS VAL FROM SYSIBM.SYSDUMMY1';
         $value = $this->fetchOne($sql);
         return (string) $value;
     }
 
     /**
      * Gets the last ID generated automatically by an IDENTITY/AUTOINCREMENT column.
      *
      * As a convention, on RDBMS brands that support sequences
      * (e.g. Oracle, PostgreSQL, DB2), this method forms the name of a sequence
      * from the arguments and returns the last id generated by that sequence.
      * On RDBMS brands that support IDENTITY/AUTOINCREMENT columns, this method
      * returns the last value generated for such a column, and the table name
      * argument is disregarded.
      *
      * The IDENTITY_VAL_LOCAL() function gives the last generated identity value
      * in the current process, even if it was for a GENERATED column.
      *
      * @param string $tableName OPTIONAL
      * @param string $primaryKey OPTIONAL
      * @param string $idType OPTIONAL used for i5 platform to define sequence/idenity unique value
      * @return string
      */
 
     public function lastInsertId($tableName = null, $primaryKey = null, $idType = null)
     {
         $this->_connect();
 
         if ($this->_isI5) {
             return (string) $this->_i5LastInsertId($tableName, $idType);
         }
 
         if ($tableName !== null) {
             $sequenceName = $tableName;
             if ($primaryKey) {
                 $sequenceName .= "_$primaryKey";
             }
             $sequenceName .= '_seq';
             return $this->lastSequenceId($sequenceName);
         }
 
         $sql = 'SELECT IDENTITY_VAL_LOCAL() AS VAL FROM SYSIBM.SYSDUMMY1';
         $value = $this->fetchOne($sql);
         return (string) $value;
     }
 
     /**
      * Begin a transaction.
      *
      * @return void
      */
     protected function _beginTransaction()
     {
         $this->_setExecuteMode(DB2_AUTOCOMMIT_OFF);
     }
 
     /**
      * Commit a transaction.
      *
      * @return void
      */
     protected function _commit()
     {
         if (!db2_commit($this->_connection)) {
             /**
              * @see Zend_Db_Adapter_Db2_Exception
              */
             // require_once 'Zend/Db/Adapter/Db2/Exception.php';
             throw new Zend_Db_Adapter_Db2_Exception(
                 db2_conn_errormsg($this->_connection),
                 db2_conn_error($this->_connection));
         }
 
         $this->_setExecuteMode(DB2_AUTOCOMMIT_ON);
     }
 
     /**
      * Rollback a transaction.
      *
      * @return void
      */
     protected function _rollBack()
     {
         if (!db2_rollback($this->_connection)) {
             /**
              * @see Zend_Db_Adapter_Db2_Exception
              */
             // require_once 'Zend/Db/Adapter/Db2/Exception.php';
             throw new Zend_Db_Adapter_Db2_Exception(
                 db2_conn_errormsg($this->_connection),
                 db2_conn_error($this->_connection));
         }
         $this->_setExecuteMode(DB2_AUTOCOMMIT_ON);
     }
 
     /**
      * Set the fetch mode.
      *
      * @param integer $mode
      * @return void
      * @throws Zend_Db_Adapter_Db2_Exception
      */
     public function setFetchMode($mode)
     {
         switch ($mode) {
             case Zend_Db::FETCH_NUM:   // seq array
             case Zend_Db::FETCH_ASSOC: // assoc array
             case Zend_Db::FETCH_BOTH:  // seq+assoc array
             case Zend_Db::FETCH_OBJ:   // object
                 $this->_fetchMode = $mode;
                 break;
             case Zend_Db::FETCH_BOUND:   // bound to PHP variable
                 /**
                  * @see Zend_Db_Adapter_Db2_Exception
                  */
                 // require_once 'Zend/Db/Adapter/Db2/Exception.php';
                 throw new Zend_Db_Adapter_Db2_Exception('FETCH_BOUND is not supported yet');
                 break;
             default:
                 /**
                  * @see Zend_Db_Adapter_Db2_Exception
                  */
                 // require_once 'Zend/Db/Adapter/Db2/Exception.php';
                 throw new Zend_Db_Adapter_Db2_Exception("Invalid fetch mode '$mode' specified");
                 break;
         }
     }
 
     /**
      * Adds an adapter-specific LIMIT clause to the SELECT statement.
      *
      * @param string $sql
      * @param integer $count
      * @param integer $offset OPTIONAL
      * @return string
      */
     public function limit($sql, $count, $offset = 0)
     {
         $count = intval($count);
         if ($count <= 0) {
             /**
              * @see Zend_Db_Adapter_Db2_Exception
              */
             // require_once 'Zend/Db/Adapter/Db2/Exception.php';
             throw new Zend_Db_Adapter_Db2_Exception("LIMIT argument count=$count is not valid");
         }
 
         $offset = intval($offset);
         if ($offset < 0) {
             /**
              * @see Zend_Db_Adapter_Db2_Exception
              */
             // require_once 'Zend/Db/Adapter/Db2/Exception.php';
             throw new Zend_Db_Adapter_Db2_Exception("LIMIT argument offset=$offset is not valid");
         }
 
         if ($offset == 0) {
             $limit_sql = $sql . " FETCH FIRST $count ROWS ONLY";
             return $limit_sql;
         }
 
         /**
          * DB2 does not implement the LIMIT clause as some RDBMS do.
          * We have to simulate it with subqueries and ROWNUM.
          * Unfortunately because we use the column wildcard "*",
          * this puts an extra column into the query result set.
          */
         $limit_sql = "SELECT z2.*
             FROM (
                 SELECT ROW_NUMBER() OVER() AS \"ZEND_DB_ROWNUM\", z1.*
                 FROM (
                     " . $sql . "
                 ) z1
             ) z2
             WHERE z2.zend_db_rownum BETWEEN " . ($offset+1) . " AND " . ($offset+$count);
         return $limit_sql;
     }
 
     /**
      * Check if the adapter supports real SQL parameters.
      *
      * @param string $type 'positional' or 'named'
      * @return bool
      */
     public function supportsParameters($type)
     {
         if ($type == 'positional') {
             return true;
         }
 
         // if its 'named' or anything else
         return false;
     }
 
     /**
      * Retrieve server version in PHP style
      *
      * @return string
      */
     public function getServerVersion()
     {
         $this->_connect();
         $server_info = db2_server_info($this->_connection);
         if ($server_info !== false) {
             $version = $server_info->DBMS_VER;
             if ($this->_isI5) {
                 $version = (int) substr($version, 0, 2) . '.' . (int) substr($version, 2, 2) . '.' . (int) substr($version, 4);
             }
             return $version;
         } else {
             return null;
         }
     }
 
     /**
      * Return whether or not this is running on i5
      *
      * @return bool
      */
     public function isI5()
     {
         if ($this->_isI5 === null) {
             $this->_determineI5();
         }
 
         return (bool) $this->_isI5;
     }
 
     /**
      * Check the connection parameters according to verify
      * type of used OS
      *
      *  @return void
      */
     protected function _determineI5()
     {
         // first us the compiled flag.
         $this->_isI5 = (php_uname('s') == 'OS400') ? true : false;
 
         // if this is set, then us it
         if (isset($this->_config['os'])){
             if (strtolower($this->_config['os']) === 'i5') {
                 $this->_isI5 = true;
             } else {
                 // any other value passed in, its null
                 $this->_isI5 = false;
             }
         }
 
     }
 
     /**
      * Db2 On I5 specific method
      *
      * Returns a list of the tables in the database .
      * Used only for DB2/400.
      *
      * @return array
      */
     protected function _i5listTables($schema = null)
     {
         //list of i5 libraries.
         $tables = array();
         if ($schema) {
             $tablesStatement = db2_tables($this->_connection, null, $schema);
             while ($rowTables = db2_fetch_assoc($tablesStatement) ) {
                 if ($rowTables['TABLE_NAME'] !== null) {
                     $tables[] = $rowTables['TABLE_NAME'];
                 }
             }
         } else {
             $schemaStatement = db2_tables($this->_connection);
             while ($schema = db2_fetch_assoc($schemaStatement)) {
                 if ($schema['TABLE_SCHEM'] !== null) {
                     // list of the tables which belongs to the selected library
                     $tablesStatement = db2_tables($this->_connection, NULL, $schema['TABLE_SCHEM']);
                     if (is_resource($tablesStatement)) {
                         while ($rowTables = db2_fetch_assoc($tablesStatement) ) {
                             if ($rowTables['TABLE_NAME'] !== null) {
                                 $tables[] = $rowTables['TABLE_NAME'];
                             }
                         }
                     }
                 }
             }
         }
 
         return $tables;
     }
 
     protected function _i5LastInsertId($objectName = null, $idType = null)
     {
 
         if ($objectName === null) {
             $sql = 'SELECT IDENTITY_VAL_LOCAL() AS VAL FROM QSYS2.QSQPTABL';
             $value = $this->fetchOne($sql);
             return $value;
         }
 
         if (strtoupper($idType) === 'S'){
             //check i5_lib option
             $sequenceName = $objectName;
             return $this->lastSequenceId($sequenceName);
         }
 
             //returns last identity value for the specified table
         //if (strtoupper($idType) === 'I') {
         $tableName = $objectName;
         return $this->fetchOne('SELECT IDENTITY_VAL_LOCAL() from ' . $this->quoteIdentifier($tableName));
     }
 
 }