Column Persisted Problem

[jsc0624]

Hi Guys,

Is this possible?

Table1:
Description     Quantity
Item 1           10

Table2:
Description     Amount
Item A           20

Persisted:

CREATE TABLE Table1
(
   DescriptionID INT IDENTITY (1,1),
   Description VARCHAR(255),
   Quantity DECIMAL(18,2)
)

CREATE TABLE Table2
(
   DescriptionID INT IDENTITY(1,1),
   Description VARCHAR(255),
   Amount DECIMAL(18,2),
   Total AS (Table1.Quantity * Amount) PERSISTED
)

Thanks in advance.

[dee-u]

What does the line

Total AS (Table1.Quantity * Amount) PERSISTED

supposed to do? I can see that it is trying to multiply the value of Table1.Quantity with the value of Amount but when you are designing it manually where are you setting such PERSISTED information?

And what database is this?

[brucevde]

The expression of a computed column can only inlcude other columns within the same table. The expression can be the result of a scalar udf function and can be persisted if the udf is considered deterministic (always returns the same result with the same parameters).

So you can do what you want by using a udf, although based on what you posted it seems like a ridiculous method to use. Describe the business problem you are trying to solve and maybe we can offer some alternatives.