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Default Constraint Question - SQL Server 2005

Posted on 2010-08-18
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Last Modified: 2012-05-10
Hi,
I was looking at documentation from Microsoft about their AdventureWorks Database :
http://msdn.microsoft.com/en-us/library/ms124879(v=SQL.100).aspx

In their SalesOrderHeader table, they have a column "SubTotal" that they define  as :
     Sales subtotal:  Computed as SUM(SalesOrderDetail.LineTotal) for the SalesOrderID.

Q:  Can this be coded as a contraint or are they referring to the application computing this value?

Thanks much in advance,
hefterr
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Question by:hefterr
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by:cyberkiwi
ID: 33470352
It is being computed by a trigger on the detail table, see trigger  SalesLT.[iduSalesOrderDetail]
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by:hefterr
ID: 33470453
Hi cyberkiwi,
Thanks for the answer BUT could you please point me to this reference.  I am not familiar with using triggers.

Thanks,
hefterr
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cyberkiwi earned 500 total points
ID: 33470687
There is no reference.
Go directly to the database in SSMS and inspect it.

The SubTotal is defined as just a simple column, not a computed column.
Also, looking at table iduSalesOrderDetail and expanding to Triggers, you see the trigger there.  Right-click modify reveals the calculation used to update the header whenever something interesting happens to a detail record.
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