Question

I am using ColdFusion 9.1.

I need to use two different datasources in some of my queries. I know it can be done because I see other code that uses two different datasources and it works fine.

I’ve tried lots of combinations but can’t get anything to work, but I know that both of my datasources are working properly.

I have a default database set up in the THIS scope. The default is “DatasourceOne”.

<cfquery>
SELECT UserID
FROM   DatasourceOne.TableOne IN (SELECT Userid FROM DatasourceTwo.TableTwo )
</cfquery

What are the rules or guidelines about using multiple datasources?

CLARIFICATION

I should have originally asked how I could use two database (not datasources) in a single query. I am sure your answers would have been different. We do have both databases set up as datasources though and I was a little confused myself.

Answer 1

Depending on your database, if the second database is on the same server (or is defined as a linked server) and the user in the datasource has permission, you can usually reference the other database.

SELECT * FROM myTable 
WHERE myField IN 
(SELECT otherField FROM otherDatabase.dbo.tableName)