Updating postgressql for hold em manager
A database connection pool contains connection information that allow us to connect to our database, such as the server name, port, and credentials.
The advantage of using a connection pool instead of directly opening a JDBC connection to a database is that database connections in a connection pool are never closed, they are simply allocated to applications as they need them.
This results in performance improvements, since the operations of opening and closing database connections are expensive in terms of performance.
The easiest way to get going is to create a user named “APP” and select a password for this user.
Clicking on the Show JDBC URL checkbox reveals the JDBC URL for the connection we are setting up.
Please hava a look at the end of the article with the book recommendation.
We then need to navigate to the location of a JAR file containing the JDBC driver. to Java DB, this attribute is used to create the database if it doesn’t exist yet.
When dealing with JPA, we don’t need to directly obtain a reference to a data source, it is all done automatically by the JPA API, but we still need to indicate the data source to use in the application’s Persistence Unit.As with all of our examples, we will be using the bundled Glass Fish application server.To create a new JPA Entity, we need to right-click on the project and select New | Entity Class.In order to do this, we need to select the New Database Connection… Net Beans includes JDBC drivers for a few Relational Database Management Systems (RDBMS) such as Java DB, My SQL, and Postgre SQL “out of the box”.Java DB is bundled with both Glass Fish and Net Beans, therefore we picked Java DB for our example.Before we can interact with a database from any Java EE 5 application, a database connection pool and data source need to be created in the application server.