Is it possible to have a mysql table accept a null value for a primary_key column referencing a diff
- by Dr.Dredel
I have a table that has a column which holds the id of a row in another table. However, when table A is being populated, table B may or may not have a row ready for table A.
My question is, is it possible to have mysql prevent an invalid value from being entered but be ok with a NULL? or does a foreign key necessitate a valid related value?
So...…