How to add Sql\Expression in front of column Name in ZF2? - zend-framework2

Question

How to get Sql like this :
select * from foo where LOWER(foo_name) = 'test';
what i get is if Sql\Expression in right, not in left.

Answer 1

You can user code snippet like that.
$where = new Where();
$sql = new Sql($adapter);
$select = $sql->select();
$where->addPredicate(new Predicate\Expression('LOWER(foo_name) = ?', 'test' ));
$select->from('foo')->where($where);
However I dont think Sql\Expression on right side is possible on Zend Framework 2.

Answer 2

You can do it like this:
$sql = new SQL($adaptor);
$select = $sql->select()->from(array('f'=>'foo'));
$select = $select->where('foo_name' => new \Zend\Db\Sql\Expression("LOWER('test')"));
Above query would return as:
SELECT `f`.* FROM `foo` AS `f` WHERE `foo_name` = LOWER('test');

Answer 3

For others out looking for similar, there are actually quite a few different ways to achieve this as of ZF 2.2
Chaining (same as the accepted answer)
<?php
$sql = new Sql($adapter);
$select = $sql->select();
$select->from( array( 'f' => 'foo' ) )
->where
->addPredicate( new Predicate\Expression( 'LOWER(f.foo_name) = ?', 'test' ) );
//SELECT `f`.* FROM `foo` AS `f` WHERE LOWER(f.foo_name) = :where1
//:where1 = 'test'
?>
Note the absence of the execution command "()" of Select::$where allowing you to continue the method chaining.
Select::$where has a __get Magic method catch which returns the protected Select::$_where property within the Select object which is an instance of Sql\Where.
Predicate\Literal 1
<?php
$select->where( "LOWER(f.foo_name) = 'test'" );
//SELECT `f`.* FROM `foo` AS `f` WHERE LOWER(f.foo_name) = 'test'
?>
Predicate\Literal 2
<?php
$select->where( array( "LOWER(f.foo_name) = 'test'" ) );
//SELECT `f`.* FROM `foo` AS `f` WHERE LOWER(f.foo_name) = 'test'
?>
The two above automatically create a Predicate\Literal object for you if the indexed value (column identifier) of the array or argument supplied to the Select::where method is a string.
Predicate\Expression (manual)
<?php
$select->where( new Predicate\Expression( "LOWER(f.foo_name) = 'test'" ) );
//SELECT `f`.* FROM `foo` AS `f` WHERE LOWER(f.foo_name) = 'test'
?>