MySQL的 - 如何从整个相关表

删除数据我有3个表MySQL的 - 如何从整个相关表

tbl_car 
id | name 
1 | toyota 

tbl_brand 
id | brand_name | **car_id** (one to many) 
1 | brand1 | 1 
2 | brand2 | 1 


tbl_item 
id | item_name | **brand_id** (one to many) 
1 | brand1_item1 | 1 
2 | brand1_item2 | 1 
3 | brand2_item1 | 2 
4 | brand2_item2 | 2

我想从tbl_car删除数据ID = 1，我尝试

DELETE tbl_car a LEFT JOIN tbl_brand b ON a.id = b.car_id LEFT JOIN tbl_item c ON b.id = c.brand_id WHERE a.id = 1

但它没有工作。我想要的是删除tbl_car id = 1和关系表中的全部数据.i感谢任何帮助，谢谢。

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2017-02-20 plonknimbuzz

看后进入on删除外键 – Mihai

我使用CASCADE选项那个，但是我读了那么多文章告诉说ON DELETE CASCADE是个坏主意。像这样http://dba.stackexchange.com/questions/74627/difference-between-on-delete-cascade-on-update-cascade-in-mysql – plonknimbuzz

@plonknimbuzz不使用级联的原因与不使用级联相同在一个语句中使用多表删除。 –

你可以试试这样：

DELETE a.*,b.*,c.* FROM tbl_car a LEFT JOIN tbl_brand b ON a.id = b.car_id LEFT JOIN tbl_item c ON b.id = c.brand_id WHERE a.id = 1

，或者尝试使用触发器表中删除tbl_car

delimiter $$ 
    CREATE TRIGGER `after_delete_Car`  
     AFTER DELETE ON `tbl_car`  
     FOR EACH ROW  
    BEGIN 
     DELETE FROM tbl_brand WHERE car_id=OLD.id; 
     DELETE FROM tbl_item WHERE brand_id=OLD.id; 
    END 
    $$ 
    delimiter ;

来源

2017-02-20 22:25:46

触发器是正确的做法。但我更喜欢删除级联。谢谢你danilo你的时间和答案 – plonknimbuzz

MySQL的 - 如何从整个相关表

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