JDBC PreparedStatement - Batch Update Example

In this article, We will discuss JDBC Batch update examples in MySQL database. Sometimes we need to run bulk queries of a similar kind for a database, for example, loading data from CSV files to relational database tables. As we know that we have the option to use Statement or PreparedStatement to execute queries. Apart from that JDBC provides Batch Processing feature through which we can execute the bulk of queries in one go for a database.
You can batch both SQL inserts, updates, and deletes. It does not make sense to batch select statements.
In this example, we will use the PreparedStatement interface to batch update.

Technologies used

  • JDK - 1.8 or later
  • MySQL - 5.7.12
  • IDE - Eclipse Neon
  • JDBC API - 4.2

Steps to process Update SQL statement with JDBC

  1. Establishing a connection.
  2. Create a statement.
  3. Execute the query.
  4. Using try-with-resources statements to automatically close JDBC resources
From JDBC 4.0, we don't need to include 'Class.forName()' in our code, to load JDBC driver. When the method 'getConnection' is called, the 'DriverManager' will automatically load the suitable driver among the JDBC drivers that were loaded at initialization and those loaded explicitly using the same class loader as the current application.
Any JDBC 4.0 drivers that are found in your classpath are automatically loaded. (However, you must manually load any drivers prior to JDBC 4.0 with the method Class.forName.)

JDBC Batch Update Example using PreparedStatement

Let's develop an example to have parameterized batch update, as shown in the following code fragment:
package com.javaguides.jdbc.batch;

import java.sql.BatchUpdateException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.Arrays;

/**
 * Update Batch operation using PreparedStatement Interface
 * @author Ramesh Fadatare
 *
 */
public class BatchUpdateExample {
    public static void main(String[] args) {
        parameterizedBatchUpdate();
    }

    public static void printSQLException(SQLException ex) {
        for (Throwable e: ex) {
            if (e instanceof SQLException) {
                e.printStackTrace(System.err);
                System.err.println("SQLState: " + ((SQLException) e).getSQLState());
                System.err.println("Error Code: " + ((SQLException) e).getErrorCode());
                System.err.println("Message: " + e.getMessage());
                Throwable t = ex.getCause();
                while (t != null) {
                    System.out.println("Cause: " + t);
                    t = t.getCause();
                }
            }
        }
    }

    private static void parameterizedBatchUpdate() {

        String UPDATE_USERS_SQL = "update users set name = ? where id = ?;";

        try (Connection connection = DriverManager
            .getConnection("jdbc:mysql://localhost:3306/mysql_database?useSSL=false", "root", "root");
            // Step 2:Create a statement using connection object
            PreparedStatement preparedStatement = connection.prepareStatement(UPDATE_USERS_SQL)) {
            connection.setAutoCommit(false);

            preparedStatement.setString(1, "A");
            preparedStatement.setInt(2, 1);
            preparedStatement.addBatch();

            preparedStatement.setString(1, "B");
            preparedStatement.setInt(2, 2);
            preparedStatement.addBatch();

            preparedStatement.setString(1, "C");
            preparedStatement.setInt(2, 3);
            preparedStatement.addBatch();

            preparedStatement.setString(1, "D");
            preparedStatement.setInt(2, 4);
            preparedStatement.addBatch();

            int[] updateCounts = preparedStatement.executeBatch();
            System.out.println(Arrays.toString(updateCounts));
            connection.commit();
            connection.setAutoCommit(true);
        } catch (BatchUpdateException batchUpdateException) {
            printBatchUpdateException(batchUpdateException);
        } catch (SQLException e) {
            printSQLException(e);
        }
    }

    public static void printBatchUpdateException(BatchUpdateException b) {

        System.err.println("----BatchUpdateException----");
        System.err.println("SQLState:  " + b.getSQLState());
        System.err.println("Message:  " + b.getMessage());
        System.err.println("Vendor:  " + b.getErrorCode());
        System.err.print("Update counts:  ");
        int[] updateCounts = b.getUpdateCounts();

        for (int i = 0; i < updateCounts.length; i++) {
            System.err.print(updateCounts[i] + "   ");
        }
    }
}
Output:
[1, 1, 1, 1]
The Connection.commit method makes the batch of updates to the Users table permanent. This method needs to be called explicitly because the auto-commit mode for this connection was disabled previously.
The following line enables auto-commit mode for the current Connection object.
connection.setAutoCommit(true);
Now each statement in the example will automatically be committed after it is executed, and it no longer needs to invoke the method commit.

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