SQL Server 2012视图中的动态SQL连接

Question

I don't really know what to title this question as because I'm not too sure about the exact terminology, however I just wanted to know if it is possible to set up a dynamic database connection inside a view.
We have a view which looks at 2 different databases. The database names are stored in another table, lets say the columns are called dbID1 and dbID2...

exampleView
SELECT a.ID, b.name 
FROM db1.dbo.IDNumbers a
INNER JOIN db2.dbo.Employees b ON a.ID = b.ID

In the exampleView the databases are hardcoded as db1.dbo and db2.dbo, is it possible to have that db1 or db2 set dynamically based on the values other table? I realize this is probably a silly example but it is just to demonstrate.

Answer 1

You need to compose your request as a string ( NVARCHAR(MAX) ), then run EXEC.

DECLARE @myRequest NVARCHAR(MAX)
SELECT @myRequest = SELECT  'SELECT * FROM (' + dbID1 + ').IDNumbers' FROM settings WHERE key = 'TableName' 
EXEC (@myRequest)

Hope this helps!