Computed column question

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Computed column question

tuffgongbob

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May 19, 2008 at 8:58 pm

#186781

Ok... here's the deal. I want to create a computed column that takes a base value in one table, and increments in the computed column table. For instance, in table a I have a base value of 100. In table b, when I insert a row, I want a computed column that takes the latest value and increments it by one, or if there isn't a latest value, it takes just the base value (100). Does anyone have any pointers on how to do this? :blink:

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Jeff Moden SSC Guru Points: 1004363 More actions · Answer 1

Can't be done... computed columns cannot refer to other tables.

You might be able to use a trigger to accomplish this. Why do you need to do this?

--Jeff Moden

RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
First step towards the paradigm shift of writing Set Based code:
________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.

Change is inevitable... Change for the better is not.

Helpful Links:
How to post code problems
How to Post Performance Problems
Create a Tally Function (fnTally)

tuffgongbob SSC Enthusiast Points: 111 More actions · Answer 2

Yikes. So I'm going to have to store redundant data, eh? I guess I could store the base value in the same table as the computed column. I wish there were a way to do it without that though.

Jeff Moden SSC Guru Points: 1004363 More actions · Answer 3

No... redundant data is not necessary. Like I said, you could use a trigger to pull this off.

Just curious... why do you want to do this? What is in the 2 tables that requires it... there may be another way...

--Jeff Moden

RBAR is pronounced "ree-bar" and is a "Modenism" for Row-By-Agonizing-Row.
First step towards the paradigm shift of writing Set Based code:
________Stop thinking about what you want to do to a ROW... think, instead, of what you want to do to a COLUMN.

Change is inevitable... Change for the better is not.

Helpful Links:
How to post code problems
How to Post Performance Problems
Create a Tally Function (fnTally)