Establishing connection to Oracle through Java

The oracle JDBC in Java is an API that enables users to access Oracle Database

from Java.

Steps to be followed to get Connection

1 Import the predefined classes.

import java.sql.*;

2 Load the drivers that acts as an interface from Java to Oracle.

Class.forName("oracle.jdbc.driver.OracleDriver");

3 Get connected to the database with your user id and password

String user,pass,url;(store user id in user and password in pass

url="jdbc:oracle:thin:@oracle.cs.uky.edu:1521:orcl";

Connection conn=DriverManager.getConnection(url,user,pass);

4 Interacting with the database from JDBC

Interaction is achieved with the help of object of class Statement

Statement stmt=conn.createStatement();

Execution of query statement

stmt.executeUpdate(any stmt);

Example : stmt.executeUpdate(“DROP TABLE EMPLOYEE”);

Execution of non-query statement

stmt.executeQuery(query stmt);

Example : stmt.executeQuery(“SELECT * FROM EMPLOYEE”);

End of statement

stmt.close();

5 Disconnecting from database

conn.close();

Note:

1 All statements mentioned above throws some exceptions so use TRY and CATCH

blocks.

2 Java is case sensitive so Caps are to be used wherever shown.

3 Any names can be used for the variables like conn, stmt, user, pass etc but it would be good if they are relevant to the data it stores.