Simple Oracle Database JDBC Connect and ExecuteQuery Example in Java

JDBC is very well known term for Java DataBase Connectivity. I think everybody who are in Java field knows term JDBC. Sometime back I’ve written an article on difference between Statement, PreparedStatement, CallableStatement. In that tutorial there is a code snippet between all 3 different statements.

In this tutorial we will go over simple Java Example which demonstrate all below steps:

• Connect to Database
• Execute SQL statement
• Retrieve Result

Are you looking for JDBC MySQL Hello World tutorial?

Java, MySQL and JDBC Hello World Tutorial – Create Connection, Insert Data and Retrieve Data from MySQL

Let’s get started:

1. create class CrunchifyMySQLJDBCConnection.java
2. Using Class.forName load the JDBC driver
3. Connect to DB using DriverManager.getConnection
4. Create statement object using crunchifyConn.createStatement
5. Execute query using crunchifyStmt.executeQuery
6. Get all results using crunchifyResultset.next()

package crunchify.com.tutorials;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

/**
 * @author Crunchify.com 
 * Simple Oracle JDBC Connection Tutorial
 */

public class CrunchifyMySQLJDBCConnection {

	static Connection crunchifyConn = null;
	static Statement crunchifyStmt = null;
	static ResultSet crunchifyResultset = null;

	public static void main(String[] args) throws SQLException {
		System.out.println("-------- Crunchify's tutorial on Oracle JDBC Connectivity  ------");

		try {
			// Returns the Class object associated with the class
			Class.forName("oracle.jdbc.driver.OracleDriver");
		} catch (ClassNotFoundException exception) {
			System.out.println("Oracle Driver Class Not found Exception: " + exception.toString());
			return;
		}

		// Set connection timeout. Make sure you set this correctly as per your need
		DriverManager.setLoginTimeout(5);
		System.out.println("Oracle JDBC Driver Successfully Registered! Let's make connection now");

		try {
			// Attempts to establish a connection
			// here DB name: localhost, sid: crunchify
			crunchifyConn = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:crunchify", "username", "password");
		} catch (SQLException e) {
			System.out.println("Connection Failed! Check output console");
			e.printStackTrace();
			return;
		}

		// Creates a Statement object for sending SQL statements to the database
		crunchifyStmt = crunchifyConn.createStatement();

		// Executes the given SQL statement, which returns a single ResultSet object
		crunchifyResultset = crunchifyStmt.executeQuery("SELECT * from CrunchifyEmployee where username = 'crunchify'");

		if (crunchifyResultset.next()) {
			System.out.println("Employee Details: " + crunchifyResultset.getString(1));
		} else {
			throw new SQLException("Can NOT retrieve Employee details from table 'CrunchifyEmployee'");
		}

		System.out.println("Oracle JDBC connect and query test completed.");
	}

}

Follow this tutorial if you want to go over similar steps for MySQL database. Steps to install MAMP and MySQL DB locally on mac.