Group items tagged

Known Causes:

First Steps:

dreaded errno 150:

The two key fields type and/or size is not an exact match

One of the key field that you are trying to reference does not have an index and/or is not a primary key

One or both of your tables is a MyISAM table

You have specified a cascade ON DELETE SET NULL, but the relevant key field is set to NOT NULL

Make sure that the Charset and Collate options are the same both at the table level as well as individual field level for the key columns

You have a default value (ie default=0) on your foreign key column

You have a syntax error in your ALTER statement or you have mistyped one of the field names in the relationship

The name of your foreign key exceeds the

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