Originally Posted by Isskint
I think we may need more information to help.
Can you provide the names of the 3 sub-tables and the relationship(s) PK/FK that link them to the Jobs table. Also a little insight into the purpose of the 3 sub-tables may help. From what you have said so far, i get a feeling your 3 sub tables are for different 'types' of jobs, in which case a single table may suit and that would make your OP simpler.
the three sub-tables have a one to many relationship with the main table "Jobs"
the first one is called "ex-works", second is called "freight rate" and the third is called "customs formality"
I work in shipping and i need to create a database to help me follow up on my quotations.
I want to add a forth sub-table for the quotations sent to clients.