How to use SQL_CALC_FOUND_ROWS with Zend\Db\TableGateway - mysql

Question

How to get SQL_CALC_FOUND_ROWS with Zend\Db\TableGateway without using direct low level queries with raw SQL?
class ProductTable {
protected $tableGateway;
/**
* Set database gateway
*
* #param TableGateway $tableGateway - database connection
* #return void
*/
public function __construct(TableGateway $tableGateway) {
$this->tableGateway = $tableGateway;
}
/**
* Fetch all products
*
* #param integer $page - page of records
* #param integer $perpage - records per page
* #return void
*/
public function fetchAll($page = 1, $perpage = 18) {
return $this->tableGateway->select(function (Select $select) use ($page, $perpage) {
$select
->limit($perpage)
->offset(($page - 1) * $perpage);
});
}
}
I wish to get total number of records in a same query used in fetchAll.

Answer 1

Looks like Zend Framework 2.1.4 has support to specify a quantifier. This enables you to use the SQL_CALC_FOUND_ROWS in a select object. One thing I did find tricky to work around is that Zend's Zend\Db\Sql\Select class will not generate the correct SQL for you if you did not specify a table. This becomes and issue when executing the subsequent select to retrieve the FOUND_ROWS(). I've updated your code below to include what I would use. I've merge my project implementation into your code, so if something does not work, its probably because I mistype something, but overall it works for me (not as desirable as I would want).
use Zend\Db\Sql\Expression;
use Zend\Db\Sql\Select;
class ProductTable {
protected $tableGateway;
/**
* Set database gateway
*
* #param TableGateway $tableGateway - database connection
* #return void
*/
public function __construct(TableGateway $tableGateway) {
$this->tableGateway = $tableGateway;
}
/**
* Fetch all products
*
* #param integer $page - page of records
* #param integer $perpage - records per page
* #return void
*/
public function fetchAll($page = 1, $perpage = 18) {
$result = $this->tableGateway->select(function (Select $select) use ($page, $perpage) {
$select
->quantifier(new Expression('SQL_CALC_FOUND_ROWS'))
->limit($perpage)
->offset(($page - 1) * $perpage);
});
/* retrieve the sql object from the table gateway */
$sql = $this->tableGateway->getSql();
/* create an empty select statement passing in some random non-empty string as the table. need this because Zend select statement will
generate an empty SQL if the table is empty. */
$select = new Select(' ');
/* update the select statement specification so that we don't incorporate the FROM clause */
$select->setSpecification(Select::SELECT, array(
'SELECT %1$s' => array(
array(1 => '%1$s', 2 => '%1$s AS %2$s', 'combinedby' => ', '),
null
)
));
/* specify the column */
$select->columns(array(
'total' => new Expression("FOUND_ROWS()")
));
/* execute the select and extract the total */
$statement = $sql->prepareStatementForSqlObject($select);
$result2 = $statement->execute();
$row = $result2->current();
$total = $row['total']';
/* TODO: need to do something with the total? */
return $result;
}
}