-629 SET NULL CANNOT BE SPECIFIED BECAUSE FOREIGN KEY `name` CANNOT CONTAIN NULL VALUES

Explanation
 The code SET NULL option of the indicated FOREIGN
KEY clause is invalid because no column of the key allows null values.
The name is the constraint-name specified in the
FOREIGN KEY clause or, if a constraint-name was not specified, the
first column-name specified in the clause.

System action
 The statement cannot be processed.

Programmer response
 Change a column of the key to allow null
values or change the delete rule.

SQLSTATE
 42834

-629 SET NULL CANNOT BE SPECIFIED BECAUSE FOREIGN KEY name CANNOT CONTAIN NULL VALUES

Explanation

System action

Programmer response

SQLSTATE

-629 SET NULL CANNOT BE SPECIFIED BECAUSE FOREIGN KEY `name` CANNOT CONTAIN NULL VALUES