Table design - PK - unique constraint?

[KrazyKoder]

Hello,

I have a junction table with composite PK on 3 fields...
[fldA], [fldB], [fldC]
I also need values to be unique across 4 values...
[fldA], [fldB], [fldC], [fldD]
I cant add the [fldD] column to the pk cause then 2 records could have the same data for [fldA], [fldB], [fldC], and that would be bad data.

Was going to add another unique constraint using all 4 fields.
Is that the best most efficent way to handle this?
Table will most likely have few records from 5 - 100.

Thanks!

[ck9663]

Hello,

I have a junction table with composite PK on 3 fields...
[fldA], [fldB], [fldC]
I also need values to be unique across 4 values...
[fldA], [fldB], [fldC], [fldD]
I cant add the [fldD] column to the pk cause then 2 records could have the same data for [fldA], [fldB], [fldC], and that would be bad data.

Was going to add another unique constraint using all 4 fields.
Is that the best most efficent way to handle this?
Table will most likely have few records from 5 - 100.

Thanks!

i'll vote for YES.....

[KrazyKoder]

Sorry I did not ask my question properly.

Having a PK on fldA, fldB & fldC would ensure that fldA, fldB, fldC & fldD are always unique. So that makes my question silly the way i originally asked it.

Let me try again with a non generic example...

Composite PK is on Strategy, Type & Priority
So far everything is good they need to be unique.
Problem is that it would be considered bad data to have the Size field be the same as in the example below.

Strategy Type Priority Size
1 1 1 1

1 1 2 1

i cant just add Size to the PK cause then that would let there be a duplicate Priority like...

Strategy Type Priority Size
1 1 1 1

1 1 1 2

So i was thinking of keeping PK the way i have it on Strategy, Type & Priority
then adding a unique constraint on all 4 Strategy, Type & Priority, Size

now i can ask...
Is this the best & most efficent way to handle this situation or is there a better way to accomplish it?

Thanks!

ck9663 - I think your vote still applies, thanks for response - anyone else?