An error occurred while creating a foreign key for MySQL.

Can't create table 'xxx. # sql-1130_1 '(errno: 150)

Cause: Check whether the two fields associated are of the same type.

Solution: Change the field type to consistent

 

Cannot add or update a child row: A foreign key constraint fails ('xxx '. '# sql-1130_1', constraint 'fk _ x1x2 'foreign key ('x1') References 'xx2 '('x2 '))

Cause: data exists in the table associated with the foreign key. The field value of the field used as the foreign key does not exist in the table to be associated, therefore, the foreign key Association of the record in the table cannot be updated.

Solution: delete data in the table that creates a foreign key association, or delete the data that does not exist in the table to be joined.