This chapter provides an example on how to delete records from a table using JDBC application. Before executing following example, make sure you have the following in place −

• To execute the following example you can replace the username and password with your actual user name and password.

• Your MySQL database you are using is up and running.

Required Steps

The following steps are required to create a new Database using JDBC application −

• Import the packages − Requires that you include the packages containing the JDBC classes needed for database programming. Most often, using import java.sql.* will suffice.

• Register the JDBC driver − Requires that you initialize a driver so you can open a communications channel with the database.

• Open a connection − Requires using the DriverManager.getConnection() method to create a Connection object, which represents a physical connection with a database server.

• Execute a query − Requires using an object of type Statement for building and submitting an SQL statement to delete records from a table. This Query makes use of the WHERE clause to delete conditional records.

• Clean up the environment − try with resources automatically closes the resources.

Sample Code

Copy and paste the following example in TestApplication.java, compile and run as follows −

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

public class TestApplication {
   static final String DB_URL = "jdbc:mysql://localhost/TUTORIALSPOINT";
   static final String USER = "guest";
   static final String PASS = "guest123";
   static final String QUERY = "SELECT id, first, last, age FROM Registration";

   public static void main(String[] args) {
      // Open a connection
      try(Connection conn = DriverManager.getConnection(DB_URL, USER, PASS);
         Statement stmt = conn.createStatement();
      ) {		      
         String sql = "DELETE FROM Registration " +
            "WHERE id = 101";
         stmt.executeUpdate(sql);
         ResultSet rs = stmt.executeQuery(QUERY);
         while(rs.next()){
            //Display values
            System.out.print("ID: " + rs.getInt("id"));
            System.out.print(", Age: " + rs.getInt("age"));
            System.out.print(", First: " + rs.getString("first"));
            System.out.println(", Last: " + rs.getString("last"));
         }
         rs.close();
      } catch (SQLException e) {
         e.printStackTrace();
      } 
   }
}

Now let us compile the above example as follows −

C:>javac TestApplication.java
C:>

When you run TestApplication, it produces the following result −

C:>java TestApplication
ID: 100, Age: 30, First: Zara, Last: Ali
ID: 102, Age: 30, First: Zaid, Last: Khan
ID: 103, Age: 28, First: Sumit, Last: Mittal
C:>