JDBC is core part of java platform and is an API specification developed by Sun Microsystems. Nearly all relational DBMSs (Database Management Systems) support SQL, and JAVA itself runs on most platforms, JDBC makes it possible to write a single database application that can run on different platforms and interact with different DBMSs.
“JDBC is similar to ODBC, but specifically designed for JAVA while ODBC is language independent.”
The JDBC driver manager is a traditional backbone of the JDBC architecture, which specifies objects for connecting Java applications to a JDBC driver. The JDBC Test Suite helps to ensure that the JDBC drivers will run the program. The JDBC-ODBC Bridge software offers JDBC access via the open database connectivity drivers.
The JDBC architecture supports two-tier and three-tier processing models for accessing a database.
Two-tier Model (Client/Server)
A Java applet or application communicates directly to the data source. The JDBC driver enables communication between the application and the data source. When a user sends a query to the data source, the answers for those queries are sent back to the user in the form of results. The data source may be located on single machine or different machine on a network to which a user is connected. This is known as a client/server configuration, where the user’s machine acts as a client and the machine having the data source running acts as the server. The network connection can be intranet or Internet.
In this model having one more layer as middle tier where the user’s commands or queries are sent to middle-tier services, from which the commands are again sent to the data source. The results are sent back to the middle tier, and from there to the user. This type of model is found very useful to makes simple to maintain access control and make updates to corporate data in database. Application deployment also becomes easy and provides performance benefits. The middle tier is usually written in C or C++.