Tutorial : Java Database Connectivity

JDBC (Java Database Connectivity) is designed to allow users to use SQL(Structured Query Language) to query databases. It makes the tasks of the developers easy as it handles all low-level concerns about particular database types.

JDBC is similar to Microsoft’s ODBC with the plus point “Platform Independence”. To use JDBC, you need to have database driver to communicate with the database. Normally drivers are installed while installing the database. Like if you install MS SQL Server, Oracle or DB2, database drivers will be installed. If you are working with MySQL, PostgreSQL or some third party database, you need to put its driver (Jar fileI into the class path.

JDBC Drivers
JDBC drivers can be broadly divided into four categories depending upon the driver implementation. The four categories/types are:
· Type 2: Native-API/partly Java driver
· Type 3: Net-protocol/all-Java driver
· Type 4: Native-protocol/all-Java driver

I will briefly talk about each type:

JDBC-OBC bridge driver is pure Java and is include in java.sql.*. The client needs ODBC driver manager and ODBC driver for data source. It is ideal in situations, when ODBC driver is available for the database and is already installed on the client machine.

Type 2 is Native code driver. It implements native JDBC interfaces using language functions in the DBMS product’s API. Type 2 drivers need platform specific library, so client and server both may run on same host. Type 2 drivers offer better performance than Type 1 drivers.

Type 3 drivers are pure Java drivers and they use middleware network protocol. They need DBMS server to implement the standard protocol to be middleware specific. The advantage is that there is no nee for any vendor database library to be present on client machines. Interesting thing is, there is no JDBC standard network protocol yet.

Type 4 drivers are pure Java drivers and they use vendor specific network protocol. These use DBMS specific network protocol (Oracle SQL Net, etc).
For the beginners, Type 1 drivers are suitable. Users simply have to make a DSN and start interacting with the database...

[Read More..]

Courtesy:- Java-forums.org