Making a connection between multiple databases
I'm using JAVA DB (derby)
I want to import a public view of my data to another database (also in java db).
I want to pass this data and save in to the other database. I'm having trouble since the general rule is one connec开发者_运维知识库tion to one database.
Help would be much appreciated.
You need two connections, one to each database.
If you want the two operations to be a single unit of work, you should use XA JDBC drivers so you can do two-phase commit. You'll also need a JTA transaction manager.
This is easy to do with Spring.
SELECT from one connection; INSERT into the other. Just standard JDBC is what I'm thinking. You'll want to batch your INSERTs and checkpoint them if you have a lot of rows so you don't build up a huge rollback segment.
I'd wonder why you have to duplicate data this way. "Don't Repeat Yourself" would be a good argument against it. Why do you think you need it in two places like this?
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