How do I know the number of rows affected when updating data in database table?

In this example you can see how to get number of rows or records affected when we update records in the database. The executeUpdate() method of Statement or PreparedStatement return an integer value which tell us how many records was affected by the executed command.

Note that when the return value for executeUpdate() method is 0, it can mean one of two things: (1) the statement executed was an update statement that affected zero row, or (2) the statement executed was a DDL statement such as statement to create a table in database.

package org.kodejava.example.jdbc;

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

public class HowManyRowExample {
    private static final String URL = "jdbc:mysql://localhost/kodejava";
    private static final String USERNAME = "root";
    private static final String PASSWORD = "";

    public static void main(String[] args) throws Exception {
        try (Connection connection =
                 DriverManager.getConnection(URL, USERNAME, PASSWORD)) {

            String sql = "UPDATE books " +
                "SET title = ?, published_year = ? " +
                "WHERE isbn = ?";

            PreparedStatement ps = connection.prepareStatement(sql);
            ps.setString(1, "Java 8 in Action, First Edition");
            ps.setInt(2, 2014);
            ps.setString(3, "9781617291999");
            int rows = ps.executeUpdate();

            System.out.printf("%d row(s) updated!", rows);
        }
    }
}

The result of the code snippet above:

1 row(s) updated!

Maven dependencies

<!-- https://search.maven.org/remotecontent?filepath=mysql/mysql-connector-java/5.1.47/mysql-connector-java-5.1.47.jar -->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.47</version>
</dependency>