I have two tables
The key to T1 is C1,C2.
The key to T2 is C1, C3
I need to create a third table T3 whose key will be C1, C2, C3
When I create the relationship from T1, C1 and C2 get imported
When I create the relationship from T2, C1 gets imported a second time.
How do I get C1 to only appear one time in T3?