Mysql workbench foreign key options [Restrict, Cascade, Set Null, No Action], what do they do?

mysql-workbench
user2310173 picture user2310173 · Apr 23, 2013 · Viewed 33.7k times · Source

In foreign key options on update and on delete. What does each field [Restrict, Cascade, Set Null, No Action] do?

Answer

Axel Agarrat picture Axel Agarrat · Apr 23, 2013

If you take one by one :

For both update and delete :

if you try to update / delete the parent row :

Restrict : Nothing gonna be delete if there is a child row

Cascade : the child row will be delete / update too

Set Null : the child column will be set to null if you delete the parent

No action : The child row will not be concern of the delete / update

Related questions

MySQL error code: 1175 during UPDATE in MySQL Workbench

I'm trying to update the column visited to give it the value 1. I use MySQL workbench, and I'm writing the statement in the SQL editor from inside the workbench. I'm writing the following command: UPDATE tablename SET columnname=1; It gives …

Read More
MySQL: How to allow remote connection to mysql

I have installed MySQL Community Edition 5.5 on my local machine and I want to allow remote connections so that I can connect from external source. How can I do that?

Read More
Access Denied for User 'root'@'localhost' (using password: YES) - No Privileges?

I am continuously receiving this error. I am using mySQL Workbench and from what I am finding is that root's schema privileges are null. There are no privileges at all. I am having troubles across platforms that my server is …

Read More