SQL Server : error joining two tables from two different databases

Question

I am using SSMS, I am trying to join two tables from two different databases, both in the same server.

The two tables have a common id column.

My query is:

select * 
from db1.dbo.EPH e 
join db2.dbo.SALARIE s on e.id = s.id

I'm getting this error:

Unable to resolve collation conflict between "Latin1_General_CI_AI" and "French_CI_AS" in operation equal to.

Answer 1

Your two databases don't have the same collation. You need to specify the "COLLATE DATABASE_DEFAULT" clause in your join.

select * from db1.dbo.EPH e join db2.dbo.SALARIE s on e.id COLLATE DATABASE_DEFAULT=s.id COLLATE DATABASE_DEFAULT

It should do the trick.

Answer 2

In Microsoft SQL Server, the collation can be set at the column level. When you compare (or concatenate) two columns having different collation in a query.

Example:

SELECT * FROM db1.dbo.EPH e
JOIN db2.dbo.SALARIE s
ON e.id COLLATE DATABASE_DEFAULT = s.id

Answer 3

Try to use COLLATE Latin1_General_CI_AS

select * 
from db1.dbo.EPH e 
join db2.dbo.SALARIE s on
e.id COLLATE Latin1_General_CI_AS = s.id
COLLATE Latin1_General_CI_AS