When creating a FK from an integer (child record) to a serial (parent record ID), PGD generates an error even though both fields are technically equivalent (integers). (PostgrSQL 9.x).
Mind And Go
Wich version of pgdesigner are you using?
Have you tried to create the relation and then change the type in the child table?
pgDesigner not understand the difference between the types, but if two fields are related, the change in the scope of the parent table is reflected in the field of the table (or tables) daughter. It is, therefore, changed the type of dependent fields.
If you want to use a particular type of field, all fields must be employees of the same type.
It is also not allowed to create partial fields, and thus should be connecting 1 to 1.