MySQL-删除相关表行

假设我有以下内容（示例结构和数据）：

在上面的示例中，当删除

列表_类别

表中的一行时，它还需要删除表

列表_标记

中的相关条目

现在我知道我可以组合表'category'和表'category_tag'，但我更喜欢将它们分开，因为

category_tag

表包含额外的字段和数据

另一个选项是将

cat_id

列添加到表

listing_tag

——但我希望尽可能避免重复数据

---

是否可以使用上表配置创建“级联删除”外键约束？如果没有，我应该如何更改表以使其工作？

在

列表\u类别

表上使用on delete触发器如何？

SELECT * FROM ints;
+---+
| i |
+---+
| 0 |
| 1 |
| 2 |
| 3 |
| 4 |
| 5 |
| 6 |
| 7 |
| 8 |
| 9 |
+---+

SELECT * FROM my_a;
+----+--------+--------+
| id | value1 | value2 |
+----+--------+--------+
|  0 |   1.00 |   2.20 |
|  1 |   2.10 |   3.50 |
|  2 |   5.20 |   2.90 |
+----+--------+--------+

DELETE x
     , y 
  FROM ints x 
  JOIN my_a y 
    ON y.id = x.i 
 WHERE y.value1 = 1.00 
    AND y.value2 = 2.2;

SELECT * FROM my_a;
+----+--------+--------+
| id | value1 | value2 |
+----+--------+--------+
|  1 |   2.10 |   3.50 |
|  2 |   5.20 |   2.90 |
+----+--------+--------+

SELECT * FROM ints;
+---+
| i |
+---+
| 1 |
| 2 |
| 3 |
| 4 |
| 5 |
| 6 |
| 7 |
| 8 |
| 9 |
+---+

SELECT * FROM ints;
+---+
| i |
+---+
| 0 |
| 1 |
| 2 |
| 3 |
| 4 |
| 5 |
| 6 |
| 7 |
| 8 |
| 9 |
+---+

SELECT * FROM my_a;
+----+--------+--------+
| id | value1 | value2 |
+----+--------+--------+
|  0 |   1.00 |   2.20 |
|  1 |   2.10 |   3.50 |
|  2 |   5.20 |   2.90 |
+----+--------+--------+

DELETE x
     , y 
  FROM ints x 
  JOIN my_a y 
    ON y.id = x.i 
 WHERE y.value1 = 1.00 
    AND y.value2 = 2.2;

SELECT * FROM my_a;
+----+--------+--------+
| id | value1 | value2 |
+----+--------+--------+
|  1 |   2.10 |   3.50 |
|  2 |   5.20 |   2.90 |
+----+--------+--------+

SELECT * FROM ints;
+---+
| i |
+---+
| 1 |
| 2 |
| 3 |
| 4 |
| 5 |
| 6 |
| 7 |
| 8 |
| 9 |
+---+