如何在不检查外键约束的情况下删除

Question

I have a table with some bad data in SQL. this table has a lot of relationship with other tables and other tables have a lot of data so when I want to delete bad data it's very slowly and take lots of time to do. I think the cause of this problem is foreign key constraints. the main problem is how can disable all of the foreign key constraints from one table.

Answer 1

You have to disable check constraint:

SET FOREIGN_KEY_CHECKS=0;

Make sure to turn it back after your commands:

SET FOREIGN_KEY_CHECKS=1;

Disable constraint for one table:

alter table
   table_name
DISABLE constraint
   constraint_name;

Here is an example:

select 'alter table '||table_name||' disable constraint '||constraint_name||';' from user_constraints;