Sets the GROUP BY part of the query.
public groupBy ( string | array | yii\db\Expression $columns ) | ||
$columns | string | array | yii\db\Expression | the columns to be grouped by. Columns can be specified in either a string (e.g. "id, name") or an array (e.g. ['id', 'name']). The method will automatically quote the column names unless a column contains some parenthesis (which means the column contains a DB expression). Note that if your group-by is an expression containing commas, you should always use an array to represent the group-by information. Otherwise, the method will not be able to correctly determine the group-by columns. Since version 2.0.7, an [[Expression]] object can be passed to specify the GROUP BY part explicitly in plain SQL. |