Been a while since I did this; turns out it’s easy enough.

First, you’ll need the current JDBC driver from Microsoft, which can be found here.  Add to classpath as usual.

Set up your Java application to use the following JDBC connection settings:

• ConnectionDriverName=com.microsoft.sqlserver.jdbc.SQLServerDriver
• ConnectionURL=jdbc:sqlserver://127.0.0.1:1433;instance=SQLEXPRESS;databaseName=jdo;
• ConnectionUserName=jdo
• ConnectionPassword=jdopass

In this case I’m connecting to SQLExpress instance running on my localhost.

The trickiest bit (for me) was figuring out how to persuade SQL Server to listen over TCP/IP – by default it only seems to listen over shared memory.  Anyway, after a bit of trial and error, the following worked.

First, locate SQL Server Configuration Manager, and enable TCP/IP for the SQL Server instance (SQLExpress in this case).

Then, right-click to open up the properties for TCP/IP, and set the port for IPAll at the bottom:

You should then be able to connect.