Relationship: Drag/Drop creates both FK and PK on same field.

Toad Data Modeler
1

To associate two tables and create a parent/child relationship:

  1. I click the “Relationship” button from the toolbar.

  2. Select the parent table and drag to the child table.

What I notice is the existing child’s foreign key field is automatically selected (good), but in addition it also creates the foreign key column as a primary key too (wrong). So what I end up with is the child table having the proper foreign key selected AND the same field is included as the primary key (wrong). I think Toad is incorrectly creating “Primary Foreign Keys”, or I need to know how to disable this.

Thanks,

Jake

2

Hi Jake,

It sounds like you are creating an Identifying relationship which would require having both columns. If you choose Non-Identifying relationship it should function as you are expecting.

Thanks!

Kevin

3

yes - Identifying relationship means RI column serves two roles: FK and part of PK. That is exactly correct and why there are two types of relationship drawing lines to choose from. Make sure to choose the right one :slight_smile:

4

Thanks for the explanation. I’ll have to educate myself more on the two relationships.

Changing to a non-identifying relationship also changes the line from solid to a dash, which most in out department aren’t used to.

5

If you also notice that non-identifying relationship leaves the child entity a square box whereas the Identifying relationship changed the child box to rounded corner. These are the industry standards which we are following. Some people are used to non-standard styles like dashed lines meaning some portion of the cardinality (e.g. oracle style called barker notation for example). That’s not standard. TDM follows the industry standards - so for IE notation (you can swicth to IDEF1X - main menu, view, notation) that’s the norm.