Run below SQL scripts to create the table and insert some dummy values in the table. For showing how we can achieve loose-coupling in connecting to databases using JDBC API, I will use Oracle and MySQL database systems. We will write program to connect to database server and run a simple jdbc query and process the results. Installing the database servers is not in the scope of this tutorial, so I will assume that you have database servers installed. Let’s create a simple JDBC Example Project and see how JDBC API helps us in writing loosely-coupled code for database connectivity.īefore starting with the jdbc example, we need to do some prep work to have some data in the database servers to query. However for this solution, we should use database specific drivers, for example OJDBC jars provided by Oracle for Oracle DB and MySQL Connector/J for MySQL databases. This solution doesn’t require any extra APIs at the client side and suitable for database connectivity over the network.

Direct-to-Database Pure Java Driver (Type 4): This is the preferred driver because it converts the JDBC calls to the network protocol understood by the database server.

Hence this is also not widely used JDBC driver. This adds to extra network calls and slow performance. We should have a middleware server installed to work with this kind of driver.

Pure Java Driver for Database Middleware (Type 3): This type of driver sends the JDBC calls to a middleware server that can connect to different type of databases.

Because of extra dependency on database client API drivers, this is also not preferred driver.

We should have database client API installed at the machine from which we want to make database connection.

Native API partly Java technology-enabled driver (Type 2): This type of driver converts JDBC class to the client API for the RDBMS servers.

We should have ODBC drivers installed in the machines from where we want to connect to database, that’s why this driver is almost obsolete and should be used only when other options are not available.

JDBC-ODBC Bridge plus ODBC Driver (Type 1): This driver uses ODBC driver to connect to database servers.

Mysql jdbc driver jar