In this tutorial you will learn about java.sql.Connection interface, and how to use this interface to get a connection to the database

JDBC Connection Example

JDBC Connection is an interface of java.sql.*;  package. An connection object represents a connection with specific database. A single application can have more than one Connection object with a single database or more databases. It create a session with a database, this session have the Sql statement to execute and results are returned.

You can get a information about a connection Connection.getMetaData() method. This method returns a MetaData object, that contains the information about database and tables.

To create a connection with database you need to call a method DriverManager.getConnection("ConnectionURL");. This returns a reference of a connection to the connection object.

Class.forName("com.mysql.jdbc.Driver");

The above code registers the river for MySql database.

Connection con=DriverManager.getConnection("jdbc:mysql://localhost:3306/student","userName","userPassword");

Now lets see an example to establish the connection to the MuSql database.

At first create a database named 'student' in MySql and then create a table named 'student'.

CREATE TABLE student (
RollNo int(9)  PRIMARY KEY NOT NULL,
Name tinytext NOT NULL,
Course varchar(25) NOT NULL,
Address text
 );

JDBCCOnnectionExample .java

package roseindia.net;

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

public class JDBCCOnnectionExample {
	Connection connection = null;

	public JDBCCOnnectionExample() {
		try {
			Class.forName("com.mysql.jdbc.Driver");
		} catch (ClassNotFoundException e) {
			System.out.println(e.toString());
		}
	}

	public Connection createConnection() {
		Connection con = null;
		if (connection != null) {
			System.out.println("Cant create a connection");
		} else {
			try {
				con = DriverManager.getConnection(
						"jdbc:mysql://localhost:3306/student", "root",
						"root");
				System.out.println("Connection created Successfully");
				DatabaseMetaData dbMetaData = con.getMetaData();
				ResultSet dbInfo = dbMetaData.getCatalogs();
				System.out.println("Getting Concurrency of MetaData");
				System.out.println(dbInfo.getConcurrency());
			} catch (SQLException e) {
				System.out.println(e.toString());
			}
		}
		return con;
	}

	public static void main(String[] args) throws SQLException {
		JDBCCOnnectionExample jdbccOnnectionExample = new JDBCCOnnectionExample();
		Connection conn = jdbccOnnectionExample.createConnection();
		conn.close();
	}
}

When you run this application it will display message as shown below:

Connection created Successfully Getting Concurrency of MetaData 1007

Download this example code

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