Can we lock tables while executing a query in Zend-Db

$db->beginTransaction();try{
    $select = $db->select()->forUpdate()// <-- here's the magic->from(
                     array('a'=>'yourTable'),
                     array('your','column','names'))->where('someColumn = ?', $whatever );

    $result = $this->_adapter->fetchRow( $select );/*
      alter data in $result
      and update if necessary:
    */
    $db->update('yourTable', $result, array('someColumn = ?'=> $whatever ));

    $db->commit();}catch(Exception $e ){
    $db->rollBack();}

// Start a transaction explicitly.
$db->beginTransaction();try{//Get your data
    $sql ="SELECT * FROM page WHERE col='value'";
    $result = $db->fetchAll($sql);//Make the insert
    $data = array('col1'=>'val1','col2'=>'val2');
    $db->insert('page', $data);// If all succeed, commit the transaction and all changes// are committed at once.
    $db->commit();}catch(Exception $e){// If any of the queries failed and threw an exception,// we want to roll back the whole transaction, reversing// changes made in the transaction, even those that succeeded.// Thus all changes are committed together, or none are.
    $db->rollBack();
    echo $e->getMessage();}