I have the situation where table a contains a mandatory association to table b and an optional association to table c.
table c also has a mandatory association to table b
Because when skipper creates the yaml file, it is putting the association to table c first.
When c_id is null in table a, then the join to table b also fails because it is via table c
If I manually edit the yaml file to put the association to table b first, then the join is successful