How to conduct cross-database querying in SQL Server?

To perform cross-database queries in SQL Server, you can use the Fully Qualified Table Name. This includes the database name, schema name, and table name in the format [database name].[schema name].[table name].

For example, to query the table Table1 in the Database1 and the table Table2 in the Database2, you can perform a cross-database query using the following method:

SELECT Database1.dbo.Table1.Column1, Database2.dbo.Table2.Column2
FROM Database1.dbo.Table1
JOIN Database2.dbo.Table2 ON Database1.dbo.Table1.CommonColumn = Database2.dbo.Table2.CommonColumn

In the example above, Database1 and Database2 are the names of the databases, dbo is the schema name (default is dbo), and Table1 and Table2 are the names of the tables. By using fully qualified table names, cross-database queries can be performed.