MYSQL Group By列

Question

我有以下MYSQL输出

Type        | Unit | Model       |Ownership         
-----------------------------------------
Drill       | BM70 | DD110       | owned
Drill       | BM81 | DD110       | owned
Light Plant | X652 | 20 KW Tower | owned
Light Plant | LT12 | 20 KW Tower | rental
Light Plant | LT13 | 20 KW Tower | rental
Light Plant | G242 | 20 KW Tower | rental

我想要显示的是类型，型号和所有权，除非我获得所有权，否则工作正常。我需要拆分拥有和租用之间的所有权，以便在我的查询后显示的输出看起来像

   Type        | Model        |Ownership         
    ------------------------------------
    Drill       | DD110       | owned
    Light Plant | 20 KW Tower | owned
    Light Plant | 20 KW Tower | rental

在SQL语句中我使用GROUP BY所有权给了我第1行和第3行，但不是第二行。这是我的确切查询，任何帮助将不胜感激：

               $order = 'equipment_model_name';

               $get_equipment = "SELECT * FROM
                    rbs_equipment_type t
                        INNER JOIN
                    rbs_equipment_model m
                        ON t.id = m.model_type_id
                        INNER JOIN
                    rbs_equipment_unit u
                        ON m.model_id = u.equipment_unit_model_id
                    GROUP BY u.ownership
                    ORDER BY $order";

Answer 1

只需在group by子句中添加类型即可。由于您没有提供列名称，我猜想会像：

GROUP BY t.type, u.ownership