如何删除外键参考表 [英] How to delete the forigne key reference table

问题描述

亲爱的所有人

如何删除原键参考表行.

表1:

id，名称(heare ID是主键)

表2:

Emp_ID，dept，ID(这里的ID是外来键参考)

Dear All

How to delete forigen key reference table rows.

table 1:

id, name (heare Id is primary key)

table 2:

Emp_ID, dept, ID (here id is forigen key reference)

推荐答案

您可以轻松地从表2中删除，但是如果要从表1中删除
使用
从table1级联删除

you can easily delete from table 2 but if you want to delete from table 1
use
delete from table1 cascade

如果要从table2中删除.要么


1.您应该从表1中删除所有相应的条目，然后只有u可以从表2中删除，否则它将显示
''DELETE语句与REFERENCE约束冲突''

2.如果您从表1中删除外键约束，则还有1个选项，那么您还可以从表2中删除行..


从表1的WHERE ID = 1
删除 GO
从table2中删除WHERE Emp_ID = 1



还有1种方法->否则在表定义中使用ON DELETE CASCADE.

If you want to delete from table2. either


1. You should to delete all the corresponding entries from table1, then only u can delete from table2,Or else it''ll show
''The DELETE statement conflicted with the REFERENCE constraint''

2. 1 more option is there if u drop the constraint of foreign key from table1, then also u can delete rows from table 2..


DELETE FROM table1 WHERE Id=1
GO
DELETE FROM table2 WHERE Emp_ID=1



1 more method -->Or Else use ON DELETE CASCADE with table Definition.

您好....

只要试试这个

ALTER TABLE table2
添加约束FK_table2ID外键(ID)
参考table1(id)
删除级联



祝你好运...

Hi there....

just try this one

ALTER TABLE table2
ADD CONSTRAINT FK_table2ID FOREIGN KEY (ID)
REFERENCES table1(id)
ON DELETE CASCADE



best of luck....

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