Reference two databases with Connection in java

Question

I have two local databases I'm trying to connect to using Java's Connection class. It's easy enough to connect to the first database using:

public Connection conn;
conn = DriverManager.getConnection(connectionString);

How can I add a second database to that same connection? They're both on the same server so it should be fairly simple but I can't find the right commands to do it.

Thanks

Answer 1

A Connection is a session with a specific database. You can't use one Connection to communicate with two different databases; for that, you need two separate Connections.

Connection conn1 =  DriverManager.getConnection(connectionString1);
Connection conn2 =  DriverManager.getConnection(connectionString2);

Answer 2

Have you tried:

public Connection conn1;
conn1 = DriverManager.getConnection(connectionString1);
public Connection conn2;
conn2 = DriverManager.getConnection(connectionString2);

Answer 3

1. Instance members shouldn't be public.

2. Connection should be a local variable, not an instance member.

You can only connect to one database at a time with a single Connection. Ergo you need another Connection.

Answer 4

我认为你必须使用J2EE，JTA事务管理器来实现这一目标。