Re: ERROR 1005: Can't create table (errno: 150) (Potential solution)

[Niranjan Hoskote]

The field being referenced as a FK, in the PARENT table, needs to be
1) either a AI or UQ
2) It has to be the same "data type" and equal in ALL respects (VARCHAR(xx)) in BOTH the field in the parent table and the FK in the child table
3) Make sure that the "Collation" is ALSO the same (latin 1 or UTF8 are the most common ones). To ensure sanity make everything the same (you can do this at the table level or at field level). BUT what is critical is that the parent AND child tables have to be the same, IF NOT the field in the parent table and the FK field in the child table has to be the same.
4) Engine has to be InnoDB
5) IF you are using a field from a table as a FK in more than one table, then make sure that the "Foreign Key Name" (a column in the MySQL Workbench) is unique. IF you use the same FK Name, it will fail.

I am a real newbie, but that is what my research has led me to.

(Also, I find it extremely hard to believe that no one has collated a better error manual for MySQL!!!!!! Strange that after years we still have the same meaningless error messages. Why is that the process that was inserting, updating, whatever could throw an error message but could not spit out a more meaningful one, I have no idea. These are fairly trivial things.)

Best .............

N-



Edited 3 time(s). Last edit at 03/05/2010 09:24AM by Niranjan Hoskote.