[英]SQL delete a specific row among several identical foreign keys but has the oldest date on it
[英]how do you delete a row, if this has foreign keys? sql
例如,如果您有这些行
create table table1
(
column1 int primary key,
column2 varchar(50),
column3 varchar(50),
column4 varchar(50),
)
create table tabla2
(
col1 int primary key,
col2 int,
col3 varchar(50),
foreign key(col2) references table1(column1)
)
例如我有一排
insert into table1(column1,column2,column3,column4) values (1,'a','b','c');
insert into table2(col1,col2,col3) values (1,1,'xxx');
我想删除所有这些行(只是他们)
delete from table1 where colum1=1;
不工作,
我知道我可以先删除另一个,然后再删除它,但是我有一个包含很多表的数据库,并且它们自另一个表以来有一个外键,我想删除该行,因为所有行都与此相关,也删除
foreign key(col2) references table1(column1) on delete cascade
http://dev.mysql.com/doc/refman/5.1/en/innodb-foreign-key-constraints.html
将ON DELETE CASCADE
添加到您的外键约束。
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