Question

In my application, I am writing data to a database.
This is the code for database writing.

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;


public class DatabaseRollback {

private static Connection getDBConnection() {

    Connection dbConnection = null;
    try {
        Class.forName("org.postgresql.Driver");
    } catch (ClassNotFoundException e) {
        System.out.println("Where is your PostgreSQL JDBC Driver? " + "Include in your library path!");
        System.out.println(e.getMessage());
        e.printStackTrace();
    }
    System.out.println("PostgreSQL JDBC Driver Registered!");

    try {
    dbConnection = DriverManager.getConnection("jdbc:postgresql://127.0.0.1:5432/MyDB","root","123");

        if (dbConnection != null) {
            System.out.println("You made it, take control your database now!");
        } else {
            System.out.println("Failed to make connection!");
        }
        return dbConnection;
    } catch (SQLException e) {
        System.out.println("Connection Failed! Check output console");
        System.out.println(e.getMessage());
        e.printStackTrace();
    }
    return dbConnection;
}

public static void main(String args[]) throws SQLException {
    Connection dbConnection = null;
    PreparedStatement pstmt = null;

    String query = "insert into orders(orderid, execid, exectype, lastprice, lastqty, ordstatus) values(?, ?, ?, ?, ?, ?)";

        try {
            dbConnection = getDBConnection();
            dbConnection.setAutoCommit(false);

            pstmt = dbConnection.prepareStatement(query); // create a statement
            pstmt.setString(1, "OrderID"); 
            pstmt.setString(2, "Test02"); 
            pstmt.setString(3, "exectype");
            pstmt.setDouble(4, 100.00);
            pstmt.setInt(5, 100);  
            pstmt.setString(6,"ordstatus"); 

            pstmt.executeUpdate(); 

            dbConnection.commit();

            query.concat("error");
            dbConnection.prepareStatement(query);
            pstmt.setString(1, "eeeeeeeeeeeeeeeeeeeeeeee");
            pstmt.executeUpdate(); // here error comes.........
        } catch (Exception e) {
        //  e.printStackTrace();
            dbConnection.rollback();
        } 
     finally {

        if (pstmt != null) {
            pstmt.close();
        }

        if (dbConnection != null && !dbConnection.isClosed()) {
            dbConnection.close();
        }

    }
}}

After debug point reach to the dbConnection.commit(); I have checked database and one record was inserted. But then it goes through dbConnection.rollback(); section. but it doesn’t rollback inserted record. How can I implement rollback machanism?

Answer 1

dbConnection.commit();

should be placed at the end of your transaction.

pstmt.setString(1, "eeeeeeeeeeeeeeeeeeeeeeee");
 pstmt.executeUpdate(); // here error comes.........
 dbConnection.commit();
        } catch (Exception e) {