MYSQL按列分组

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

我想展示的是类型、型号和所有权，除了我拥有所有权之外，这些都很好用。我需要在拥有和租用之间分离所有权，以便查询后显示的输出如下所示

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

在SQL语句中，我使用的GROUPBY OWNERSH给出了第一行和第三行，但不是第二行。以下是我的确切问题，如有任何帮助，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";

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只需在GROUPBY子句中添加类型。由于您没有提供列名称，我猜可能是这样的：

GROUP BY t.type, u.ownership