[Postgres] Replace LIKE with IIKE (output walker)

IlikeWalker.php

<?php
namespace XXX\SearchBundle\Doctrine;

use Doctrine\ORM\Query\SqlWalker;

/**
 * Replace LIKE with ILIKE
 * Usage: $query->setHint(Query::HINT_CUSTOM_OUTPUT_WALKER, 'XXX\SearchBundle\Doctrine\IlikeWalker');
 *
 * @author Ziumin
 */
class IlikeWalker extends SqlWalker
{
	/**
	 * Walks down a WhereClause AST node, thereby generating the appropriate SQL.
	 *
	 * @param WhereClause $whereClause
	 *
	 * @return string The SQL.
	 */
	public function walkWhereClause($whereClause)
	{
		$sql = parent::walkWhereClause($whereClause);
		$sql = str_replace('LIKE', 'ILIKE', $sql);

		return $sql;
	}
}