Java MySQL JDBC Tutorial using NetBeans Part 2

n first part, we have already established connection to MySQL using Java. Now, we will discuss about how to modify the record of the database from program we make.

Make sure that you have read the previous part of the tutorial. In this tutorial, we will use Project that we have created in previous tutorial and Statement interface from java.sql.Statement.

First we must have a database and a table in MySQL. For example, we create a database school with attribute name and number (student number). Start your MySQL and make such database and table using this command :

create database school;
use school;
create table student (name varchar(30), number int);

Set student number to be the primary key on this table:

alter table student add constraint primary key (number);

After finishing with database, we move to our Java program.

In Statement interface, we can execute any SQL statemnt using our Java program. First, make a class named Sqlstatement in our previous tutorial Project. The content of Sqlstatement.java is :

package javasql;
import java.sql.*;
/**
 *
 * @author ferdiansyah.dolot
 */
public class Sqlstatement {
    private Statement statement;
    public Sqlstatement() throws SQLException{
        makeStatement();
    }
    public Statement makeStatement() throws SQLException{
        Connect c = new Connect();
        Connection conn = c.makeConnection();
        statement = conn.createStatement();
        return statement;
    }
    public void insert(String nama,int npm)throws SQLException{
        statement.execute("insert into student values(\""+name+"\",
                          "+number+")");
    }
    public static void main(String arg[]){
        try {
            Sqlstatement s = new Sqlstatement();
            s.insert("Ferdi",1);
            s.insert("Anca",2);
            System.out.println("Success");
        }
        catch(SQLException e){
            System.out.println("Failed");
            e.printStackTrace();
        }
    }
}

In class above, we use the Connect class that we have created in previous tutorial.

On this part :

statement = conn.createStatement();

Variable conn is instance of Connect class that we have made in the previous tutorial. After the connection has estabished, the conn call method createStatement(). The method returns Statement that we will use to send SQL statements to database.

To execute any SQL statement using our Java program, we use execute(String sqlstatement) in interface Statement. In our program above, the execution of the SQL statement can be seen on this part :

statement.execute(“insert into student values(\”"+name+”\”,”+number+”)”);

After that, run the Sqlstatement program ( in Netbeans, press Shift+ F6). See what happened in you database record. You can see values in your database and table using command :

select * from student;

You can see the value you insert using Sqlstatment class will be in table values.

API for Statement interface in Java can be seen on http://java.sun.com/javase/6/docs/api/java/sql/Statement.html.

source :

http://ferdidolot.wordpress.com/2009/06/18/java-mysql-jdbc-tutorial-using-netbeans-part-2/