Foreign key issue:ERROR 1005 (HY000): Can't create table (errno: 150)

Question

I\'m getting this error: ERROR 1005 (HY000): Can\'t create table (errno: 150); I know it has something to do with the foreign keys but I have checked to see if they

Answer 1

You have FK definitions that will try to set a null value on non null columns. Therefore that FK declaration is impossible.

CREATE TABLE IF NOT EXISTS registration (
  branchNo VARCHAR (15) NOT NULL,
  memberNo VARCHAR (15) **NOT NULL**,
  StaffNo VARCHAR (15) **NOT NULL**,
  dateJoined date NOT NULL,
  PRIMARY KEY (branchNo, memberNo), 
FOREIGN KEY (memberNo) REFERENCES member (memberNo) ON DELETE **SET NULL** ON UPDATE 
CASCADE, 
FOREIGN KEY (StaffNo) REFERENCES staff (StaffNo) ON DELETE **SET NULL** ON UPDATE 
CASCADE
) ENGINE=InnoDB;

you can either set "on DELETE CASCADE" or allow those fields to be null.

You might have the same error on other tables. I just stopped at the first error I found :)

Answer 2

Solved:

Check to make sure Primary_Key and Foreign_Key are exact match with data types.

If one is signed another one unsigned, it will be failed.
Good practice is to make sure both are unsigned INT.