Hi all,

I have two tables: Users and companies. Both have field EMAIL as unique

Is there any way to prevent duplicated email acrosss different tables?
The idea is to prevent a company and a user with same email address.

Currently I check it at moment of register wether the email exists on both tables, but I'd like to have something more solid.

I'm using MySQL 5, MyISAM

Thanks in advance

You can't do that.

why not redesign your db and have a table to hold unique email addresses and created FK's from the other 2 tables.

Not with MyISAM

oooooopsie.

Using 1 table instead of 2, you can solve your problem:

TableA
-------
1- Email (PK)
2- Type: User/Company
3- ...