Computed column formula with join

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Computed column formula with join

Atif

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September 6, 2008 at 3:00 am

#197819

I have a column c1 in a table T1, there is another table t2 with column c2.
I am required to prepare a formula for a computed column in t2.
Formula will check that if c2 is less than c1 then computed value will be 0, and if c2 > = c1 then computed value will be 1.
How to prepare such formula with join between t1 and t2.
DBDigger Microsoft Data Platform Consultancy.

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John H Marsh SSChampion Points: 11671 More actions · Answer 1

Hello,

You would probably want to create the Computed Column from a Case statement based on column c2, with the if/else logic comparing it to column c1.

Regards,

John Marsh

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Carl Federl One Orange Chip Points: 25384 More actions · Answer 2

A computed column cannot be used as defining expression may only reference base columns within the same table.

You will need to add a physical column and then use a trigger to maintain the value.

SQL = Scarcely Qualifies as a Language

Jeff Moden SSC Guru Points: 1004414 More actions · Answer 3

Like Carl said... can't be done by a computed column... but, you could use a view for this. Carl also suggested that you could use a trigger and that would work, as well.

--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.

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