Create SQL user-defined function in ColdFusion with MS SQL Server - sql-server

Question

I'm doing queries in which I want to extract the left-most n characters from a string that has been stripped of all leading and following spaces. An example is:
Select SUBSTRING(LTRIM(RTRIM(somefield)), 0, #n) AS mydata
FROM sometable
It's the only way I can figure to do it on a SQL Server.
I've never written a UDF before, but I think if I was just working on a SQL Server, I could create a user-defined function such as:
CREATE FUNCTION udfLeftTrimmed
(
#inputString nvarchar(50),
#n int
)
RETURNS nvarchar(#n)
AS
BEGIN
RETURN SUBSTRING(LTRIM(RTRIM(#inputString)), 0, #n);
END
I could then do something like:
Select udfLeftTrimmed(somefield,6) AS mydata
FROM sometable
which is at least a little easier to read and understand.
The question is, how do I create the UDF in ColdFusion? All my searches for SQL user-defined function in ColdFusion just gave me how to create ColdFusion functions.

Answer 1

Since there is nothing special or "dynamic" about your UDF you really don't need to create it in CF. You should just create it using MSSQL Manager. UDFs in SQL are like stored procedures. Once created they are a part of the DB/Schema. so create once, use as many times as you like (as #leigh has mentioned).
Keep in mind that using a SQL udf in SQL usually requires the user prepend as in:
<cfquery...>
Select dbo.udfLeftTrimmed(somefield,6) AS mydata
FROM sometable
</cfquery>
Note the "dbo.udf..." that dbo is important and may be why your subsequent try is failing - besides getting a duplicate UDF error by now. :)
NOTE:
To follow up on your comments and Leighs, you can create your UDF in a DB accessible to your user then access it as dbo.dbname.function ... as inthe following code:
<cfquery...>
Select dbo.myspecialDatabase.udfLeftTrimmed(somefield,6) AS mydata
FROM sometable
</cfquery>
Then you need only create it one time.