Deleting Records using the Prepared Statement
This section helps us for deleting the records from the database table by using the PreparedStatement interface of the java.sql package. Sometimes, some records we have entered becomes useless after sometime so we need to delete those records. We can do it very easily by using the simple Sql query. The given example provides the facility for deleting the records from the database table. Brief description below: Please go through this example very carefully.
Description of program:
In this program we are going to delete the records from the 'movies' table that released in the year 1985. For this, first of all we will establish the connection with MySQL database by using the JDBC driver. After establishing the connection we will pass the SQL statement in the prepareStatemet method which returns the PreparedStatement object and we will set the releases year of movies in the setInt method by using the PreparedStatement object. If it records gets delete then the executeUpdate method will return the number of deleted records. This method will execute the SQL statement that may be INSERT, UPDATE or DELETE statement. If any problems arises with SQL statement then it will display a message "SQL statement is not executed!".
Here is the code of program:
import java.sql.*;
public class DeleteRecords{
public static void main(String[] args) {
System.out.println("Delete records example using prepared statement!");
Connection con = null;
try{
Class.forName("com.mysql.jdbc.Driver");
con = DriverManager.getConnection
("jdbc:mysql://localhost:3306/jdbctutorial","root","root");
try{
String sql = "DELETE FROM movies where year_made = ?";
PreparedStatement prest = con.prepareStatement(sql);
prest.setInt(1,1985);
int del = prest.executeUpdate();
System.out.println("Number of deleted records: " + del);
con.close();
}
catch (SQLException s){
System.out.println("SQL statement is not executed!");
}
}
catch (Exception e){
e.printStackTrace();
}
}
}
Database Table: movies
| title | year_made |
| alam ara | 1945 |
| Bagal bali | 2002 |
| Karan | 1996 |
| Bagban | 2003 |
| Kuch kuch hota hi | 1985 |
| Ham hi tumahare sanam | 1985 |
Output of the program:
| C:\vinod\jdbc\jdbc\PreparedStatement>javac DeleteRecords.java C:\vinod\jdbc\jdbc\PreparedStatement>java DeleteRecords Delete records example using prepared statement! Number of deleted records: 2 |
After executing the program:
Database Table: movies
| title | year_made |
| alam ara | 1945 |
| Bagal bali | 2002 |
| Karan | 1996 |
| Bagban | 2003 |