Oracle: JDBC (Java Database Connectivity)

What Is JDBC?

JDBC (Java DataBase Connectivity) is the specification of the standard application programming interface that provides a standard library for accessing relational databases like MS Access, Oracle, or Sybase. It also provides a common base on which higher-level tools and interfaces can be built. It is an application programming interface that defines how a Java programmer can access the database in tabular format from Java code using a set of standard interfaces and classes written in the Java programming language.

How JDBC Helps us?

• To connect to a data source, like a database.
• In sending queries and updating statements to the database
• Retrieve and process the results received from the database in terms of answers to your query.

How To Implement JDBC API?

The implementation of the JDBC API can only be possible through JDBC Drivers. The API interface is made up of 4 main interfaces:

• java.sql DriverManager
• java.sql.Connection
• java.sql.Statement
• java.sql.Resultset

Architecture of JDBC Driver

Types of JDBC Drivers

• JDBC-ODBC Bridge
• Native-API partly Java technology-enabled driver
• A net-protocol fully Java technology-enabled driver
• A native-protocol, fully Java technology-enabled driver

Diagrammatical representation of the different JDBC Drivers

Types of JDBC SQL Statements

1. java.sql.Statement: Topmost interface, which provides basic methods useful for executing SELECT, INSERT, UPDATE, and DELETE SQL statements.
2. java.sql.PreparedStatement: An enhanced version of java.sql.Statement, which allows precompiled queries with parameters.
3. java.sql.CallableStatement: It allows you to execute stored procedures within an RDBMS that supports stored procedures.

How to use JDBC?

• First of all, load the drivers of JDBC.
• Secondly, define the URL for the Connection.
• Thirdly, establish the connection.
• Further, create an object of the statement.
• Execute the Query.
• Now process the results and
• Close the connection.

Brief description of another widely used interface: ODBC

ODBC 

ODBC is the most widely used interface to access the database. It is a multi-database API for programs that use SQL statements to access data. With the use of ODBC, we can access any data from any application regardless of which database management system (DBMS) is handling the data. We cannot use ODBC directly with Java programs; rather, we have to make use of JDBC with ODBC to develop Java database applications.

Difference between JDBC and ODBC
 

	JDBC	ODBC
Definition	Java Database Connectivity API for data connections for Data and Java Class.	Object Database Connectivity driver for Microsoft specification and desktop applications.
Design	Simple design with advanced capabilities available.	Mixes simple and advanced features together and has complex options for simple queries.
Language	JDBC drivers are written in Java.	ODBC is not dependent upon any language.
Installation	JDBC code is automatically installable, secure, and portable on all platforms.	Requires manual installation of the ODBC driver manager and driver on all client machines.

The architecture of ODBC Driver

ODBC Driver