php - ZEND2 - lastInsertValue returns NULL -

my table looks this:

create table data.brand_list (   id bigserial not null,   brand_name text,   created_at timestamp time zone default now(),   ghost boolean,   constraint brand_list_id_pkey primary key (id) ) 

it has sequence:

 create sequence data.brand_list_id_seq  increment 1  minvalue 1  maxvalue 9223372036854775807  start 649  cache 1;  alter table data.brand_list_id_seq 

my code in zend model:

public function addrow(brandlist $brandlist) {     $data = array(         'id' => $brandlist->id,         'brand_name' => $brandlist->brand_name,         'created_at' => $brandlist->created_at,         'ghost' => $brandlist->ghost,     );      $id = (int)$brandlist->id;     if ($id == 0) {         unset($data['id']);         $row = $this->tablegateway->insert($data);         var_dump($this->tablegateway->getlastinsertvalue());die;         return $id;     } else {         if ($this->findone($id)) {             $this->tablegateway->update($data, array('id' => $id));         } else {             throw new \exception('form id not exist');         }     } } 

and $row return int(1) always, $this->tablegateway->getlastinsertvalue() returns null. doing wrong? i've tried everything... no luck.

you can try raw query see if getting result want.

  $adapter = $this->tablegateway->getadapter(); 

$rowset = "select max(id)...";  $resultset = $adapter->query($rowset,array());  $rowdata = $resultset->toarray(); return $rowdata; 

or

use zend\db\sql\sql; use zend\db\sql\select; use zend\db\sql\expression;     $adapter = $this->tablegateway->getadapter();     $sql = new sql($adapter);     $select = $sql->select();     $select->from('table_name')->columns(array('id' => new expression('max(id)') ));     $selectstring = $sql->getsqlstringforsqlobject($select);     $results = $adapter->query($selectstring, $adapter::query_mode_execute);     $resultset = new resultset();     $resultset->initialize($results);     return $resultset->toarray();