Since no one mentioned it, but it is timesaver, as a general rule, you can use **Database_Default** collation so you don't need to figure out which one to use. However, I strongly suggest reading Simons Liew's excellent article [Understanding the COLLATE DATABASE_DEFAULT clause in SQL Server](https://www.mssqltips.com/sqlservertip/4395/understanding-the-collate-databasedefault-clause-in-sql-server/)
``` SELECT * FROM [FAEB].[dbo].[ExportaComisiones] AS f JOIN [zCredifiel].[dbo].[optPerson] AS p ON (p.vTreasuryId = f.RFC) COLLATE Database_Default ```

As a general rule, you can use **Database_Default** collation so you don't need to figure out which one to use. However, I strongly suggest reading Simons Liew's excellent article [Understanding the COLLATE DATABASE_DEFAULT clause in SQL Server][1]
SELECT * FROM [FAEB].[dbo].[ExportaComisiones] AS f JOIN [zCredifiel].[dbo].[optPerson] AS p ON (p.vTreasuryId = f.RFC) COLLATE Database_Default


[1]: https://www.mssqltips.com/sqlservertip/4395/understanding-the-collate-databasedefault-clause-in-sql-server/