Justin Cooney

User defined functions are a useful tool when working with SQL Server. However recently as Luvy and I were working on creating a stored procedure we found out that user defined functions cannot be executed across a linked server in the usual way. We ran our tests on SQL Server 2008, but I believe this issue is applicable in SQL Server 2000 and 2005 as well.

The specific problem we encountered was that we wanted to select data from a user defined function via the linked server into a temporary table while passing variable parameters to the function.

After some trial and error we discovered two ways that one can execute user defined functions via a linked server. One can use the command: Openquery or one can use the command sp_executesql

We first tried using the command Openquery, but encountered roadblocks when when passing in parameter variables.

Then when we tried using the sp_executesql command, which ended up working like a charm.

Below is an example of the sp_executesql command we ran cross server using two parameter variables called Field1 and Field2.

declare @Field1 char(4)
declare @Field2 char(8)
set @Field1 ='1234'
set @Field2 = '567'

INSERT INTO #TheTempTable
(Field1,
Field2,
Amt,
[Year],
[Month]
)exec CROSSSERVER.databasename.dbo.sp_executesql N'
SELECT @Field1,@Field2,* 
from databasename.dbo.dbFnc(@FromDate,@ToDate,@Charge)',
N'@Field1 char(4),@Field2 char(8),
@FromDate smalldatetime,@ToDate smalldatetime,
@Charge money',@Field1=@Field1,
@Field2=@Field2,@FromDate=@FromDate,@ToDate=@ToDate,
@Charge=@Charge

select * from #TheTempTable
drop table #TheTempTable

References:

• MSDN tSQL Documentation
• Microsoft Support
• PRB: User-Defined Function Call in Four-Part Linked Server Query Fails with Error Message 170
• SQLTeam: How To Call A UDF From Different Server