• Java Database Connectivity (JDBC)
• RDBMS understand SQL language only.
• JDBC driver converts Java requests in database understandable form and database response in Java understandable form.
• JDBC drivers are of 4 types

Type I - Jdbc Odbc Bridge driver

• ODBC is standard of connecting to RDBMS (by Microsoft).
• Needs to create a DSN (data source name) from the control panel.
• From Java application JDBC Type I driver can communicate with that ODBC driver (DSN).
• The driver class: sun.jdbc.odbc.JdbcOdbcDriver -- built-in in Java.
• database url: jdbc:odbc:dsn
• Advantages:
  • Can be easily connected to any database.
• Disadvantages:
  • Slower execution (Multiple layers).
  • The ODBC driver needs to be installed on the client machine.

Type II - Partial Java/Native driver

• Partially implemented in Java and partially in C/C++. Java code calls C/C++ methods via JNI.
• Different driver for different RDBMS. Example: Oracle OCI driver.
• Advantages:
  • Faster execution
• Disadvantages:
  • Partially in Java (not truely portable)
  • Different driver for Different RDBMS

Type III - Middleware/Network driver

• Driver communicate with a middleware that in turn talks to RDBMS.