How to INSERT data into a MySQL database using Java

A guide on how to use Prepared Statements in Java to insert data into a table in a MySQL database safely and effectively.

In this article, you'll learn how to connect to a MySQL database and use Java with Prepared Statements to execute an INSERT statement, allowing you to add new records to a table in the database.

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

public class InsertDataExample {
    public static void main(String[] args) {
        String url = "jdbc:mysql://localhost:3306/test_db";
        String user = "root";
        String password = "password";

        String insertQuery = "INSERT INTO students (name, age, email) VALUES (?, ?, ?)";

        try (Connection conn = DriverManager.getConnection(url, user, password);
             PreparedStatement pstmt = conn.prepareStatement(insertQuery)) {

            // Set values for parameters
            pstmt.setString(1, "John Doe");
            pstmt.setInt(2, 20);
            pstmt.setString(3, "[email protected]");

            // Execute the INSERT statement
            int rowsAffected = pstmt.executeUpdate();
            System.out.println(rowsAffected + " record(s) added.");

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Detailed explanation:

1. import java.sql.Connection;: Imports the Connection class to establish a database connection.
2. import java.sql.DriverManager;: Imports the DriverManager class to manage database connections.
3. import java.sql.PreparedStatement;: Imports the PreparedStatement class to execute SQL statements with safe parameters.
4. String url = "jdbc:mysql://localhost:3306/test_db";: Defines the connection URL to the MySQL database.
5. String user = "root"; and String password = "password";: Declares the user credentials for connecting to the database.
6. String insertQuery = "INSERT INTO students (name, age, email) VALUES (?, ?, ?)";: Defines the INSERT statement with parameters.
7. try (Connection conn = DriverManager.getConnection(url, user, password);: Establishes the database connection in a try-with-resources block.
8. PreparedStatement pstmt = conn.prepareStatement(insertQuery): Creates a PreparedStatement from the defined INSERT statement.
9. pstmt.setString(1, "John Doe");: Sets the value for the first parameter in the INSERT statement.
10. pstmt.setInt(2, 20);: Sets the value for the second parameter in the INSERT statement.
11. pstmt.setString(3, "[email protected]");: Sets the value for the third parameter in the INSERT statement.
12. int rowsAffected = pstmt.executeUpdate();: Executes the INSERT statement and stores the number of affected rows in rowsAffected.
13. System.out.println(rowsAffected + " record(s) added.");: Prints the number of records successfully added.
14. catch (Exception e) { e.printStackTrace(); }: Catches and handles exceptions that occur during execution.

System Requirements:

• JDK 8 or higher
• Library: mysql-connector-java

How to install the libraries needed to run the Java code above:

• Download the mysql-connector-java library from the official MySQL website and add it to your Java project. If you are using Maven, you can add the following dependency to your pom.xml file:

<dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>8.0.32</version> </dependency>

Tips:

• Make sure your MySQL server is running before attempting to connect.
• Double-check your connection details like url, user, and password to avoid connection errors.
• Use Prepared Statements to protect against SQL injection attacks.