MySQL: Can't create table (errno: 150)

Question

I am trying to import a .sql file and its failing on creating tables.

Here\'s the query that fails:

CREATE TABLE `data` (
`id` int(10) unsigned NOT NUL         


        

Answer 1

In some cases, you may encounter this error message if there are different engines between the relating tables. For example, a table may be using InnoDB while the other uses MyISAM. Both need to be same

Answer 2

Error no. 150 means a foreign key constraint failure. You are probably creating this table before the table the foreign key depends on (table keywords). Create that table first and it should work fine.

If it doesn't, remove the foreign key statement and add it after the table is created - you will get a more meaningful error message about the specific constraint failure.

Answer 3

In most of the cases the problem is because of the ENGINE dIfference .If the parent is created by InnoDB then the referenced tables supposed to be created by MyISAM & vice versa

Answer 4

I got the same problem when executing a series of MySQL commands. Mine occurs during creating a table when referencing a foreign key to other table which was not created yet. It's the sequence of table existence before referencing.

The solution: Create the parent tables first before creating a child table which has a foreign key.

Answer 5

A real edge case is where you have used an MySQL tool, (Sequel Pro in my case) to rename a database. Then created a database with the same name.

This kept foreign key constraints to the same database name, so the renamed database (e.g. my_db_renamed) had foreign key constraints in the newly created database (my_db)

Not sure if this is a bug in Sequel Pro, or if some use case requires this behaviour, but it cost me best part of a morning :/

Answer 6

Please make sure both your primary key column and referenced column have the same data types and attributes (unsigned, binary, unsigned zerofill etc).