To make it connect to northwind, do the following:

• Go to http://sourceforge.net/projects/jtds/files/  and download jtds-1.2.4-dist.zip
• Unzip jtds-1.2.4-dist.zip and extract:
• jtds-1.2.4.jar into C:\Program Files\Java\jdk1.6.0_16\jre\lib\ext ( or whichever version you are using in BlueJ – Find from BlueJ about button)
• put ntlmauth.dll in C:\Program Files\Java\jdk1.6.0_16\jre\bin 
  
• In your code: (see testconnection2.java)
  
• import java.sql.*
  
• define the driver with the command  Class.forName("net.sourceforge.jtds.jdbc.Driver");
  
• this says we are using the jtds driver, an open source driver.
  
• this requires a catch of Exception e
  
• create a Connection object  using the DriverManager.getConnection method, passing it "jdbc:jtds:sqlserver://localhost/Northwind;instance=sqlexpress"
• the connection object knows the database.
  
• create a Statement object for that connection with <your Connection object>.createStatement()
  
• I think you can have multiples, but am not sure
• If you don't want a result row back, tell your Statement object to execute a string which is an SQL statement   as <your statement object>.execute ("your sql statement with no ;")
• If you want a result row back, tell your Statement object to execute a string which is an SQL statement as ResultSet <name a variable> = <your statement object>.executeQuery("your sql statement")
• read it by telling your result set to go to the next line with result.next();
• then result.getString("column name");
  
• To manage 2 different database connections, create a class with no variables and pass it the database connection string. Let the class do all the connection and sql statement execution.
  
• It doesn't need any instance variables.
  
• see sample
  
• Here is an example with a menu. The loop to take in a menu option isn't working quite right.
  

Great site: http://softwaresalariman.blogspot.com/2007/04/jdbc-to-sql-server-express.html --- but we used windows authentication. The  readme.sso from the zip file said to put ntlmauth.dll in C:\Program Files\Java\jdk1.6.0_16\jre\bin 

Got sample code here: http://www.java-tips.org/other-api-tips/jdbc/how-to-connect-microsoft-sql-server-using-jdbc.html