Database DbQuery Class

To create an SQL query you will need DbQuery class which is a query builder. For example,

$sql = new DbQuery();
$sql->select('*');
$sql->from('cms', 'c');
$sql->innerJoin('cms_lang', 'l', 'c.id_cms = l.id_cms AND l.id_lang = '.(int)$id_lang);
$sql->where('c.active = 1');
$sql->orderBy('position');
return Db::getInstance()->executeS($sql);

Here is a list of some of the methods from this class:

Name of the method and parameter	Description
__toString()	Create and get the query.
build()	Create and get the query (return a string).
from(string $table, mixed $alias = null)	Set table for FROM clause.
groupBy(string $fields)	Add a GROUP BY restriction.
having(string $restriction)	Add a restriction in the HAVING clause (each restriction will be separated by an AND statement).
innerJoin(string $table, string $alias = null, string $on = null)	Add a INNER JOIN clause, E.g. $this->innerJoin('product p ON ...').
join(string $join)	Add a JOIN clause, E.g. $this->join('RIGHT JOIN'.DB_PREFIX.'product p ON ...');.
leftJoin(string $table, string $alias = null, string $on = null)	Add a LEFT JOIN clause.
leftOuterJoin(string $table, string $alias = null, string $on = null)	Add a LEFT OUTER JOIN clause.
limit(string $limit, mixed $offset = 0)	Limit results in query.
naturalJoin(string $table, string $alias = null)	Add a NATURAL JOIN clause.
orderBy(string $fields)	Add an ORDER B restriction.
select(string $fields)	Add fields in query selection.
where(string $restriction)	Add a restriction in WHERE clause (each restriction will be separated by an AND statement).