public function update($tableName)
    {
        $this->_queryType = self :: UPDATE;
        $this->_update    = $tableName;

        return $this;
    }
public function update($tableName)
    {
        $this->_queryType = self :: UPDATE;
        $this->_update    = $tableName;

        return $this;
    }
public function update ( $ tableName ) { $ this -> _queryType = self :: UPDATE ; $ this -> _update = $ tableName ; return $ this ; }
Configure object for UPDATE query
and set the main table name

@param $tableName

@return $this
Configure object for UPDATE query and set the main table name