How to Connect to MySQL in Spring Boot: Simple Guide

To connect to MySQL in Spring Boot, add the spring-boot-starter-data-jpa and mysql-connector-java dependencies, then configure your database details in application.properties. Spring Boot will auto-configure the connection using these settings.

Syntax

To connect Spring Boot to MySQL, you need to add dependencies and configure connection properties.

• Dependencies: Include spring-boot-starter-data-jpa for JPA support and mysql-connector-java for MySQL driver.
• Configuration: Set database URL, username, password, and driver class in application.properties.
• Entity and Repository: Define JPA entities and repositories to interact with the database.

properties

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-data-jpa'
    runtimeOnly 'mysql:mysql-connector-java'
}

# application.properties
spring.datasource.url=jdbc:mysql://localhost:3306/your_database
spring.datasource.username=your_username
spring.datasource.password=your_password
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

spring.jpa.hibernate.ddl-auto=update
spring.jpa.show-sql=true

Example

This example shows a simple Spring Boot application connecting to MySQL, defining an entity, and saving data.

java

package com.example.demo;

import jakarta.persistence.Entity;
import jakarta.persistence.Id;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;
import org.springframework.beans.factory.annotation.Autowired;

@SpringBootApplication
public class DemoApplication implements CommandLineRunner {

    @Autowired
    private UserRepository userRepository;

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }

    @Override
    public void run(String... args) throws Exception {
        User user = new User();
        user.setId(1L);
        user.setName("Alice");
        userRepository.save(user);
        System.out.println("User saved: " + user.getName());
    }
}

@Entity
class User {
    @Id
    private Long id;
    private String name;

    public Long getId() { return id; }
    public void setId(Long id) { this.id = id; }
    public String getName() { return name; }
    public void setName(String name) { this.name = name; }
}

@Repository
interface UserRepository extends JpaRepository<User, Long> {}

Output

User saved: Alice

Common Pitfalls

Common mistakes when connecting Spring Boot to MySQL include:

• Forgetting to add the mysql-connector-java dependency, causing driver not found errors.
• Incorrect JDBC URL format; it must start with jdbc:mysql:// and include the database name.
• Using wrong driver class name; the correct one is com.mysql.cj.jdbc.Driver for recent MySQL versions.
• Not setting spring.jpa.hibernate.ddl-auto properly, which can cause schema issues.
• MySQL server not running or wrong credentials causing connection failures.

properties

/* Wrong JDBC URL example */
spring.datasource.url=jdbc:mysql://localhost/your_database

/* Correct JDBC URL example */
spring.datasource.url=jdbc:mysql://localhost:3306/your_database

Quick Reference

Summary tips for connecting Spring Boot to MySQL:

• Always use spring-boot-starter-data-jpa and mysql-connector-java dependencies.
• Configure application.properties with correct URL, username, password, and driver.
• Use com.mysql.cj.jdbc.Driver as the driver class name.
• Set spring.jpa.hibernate.ddl-auto to update for automatic schema updates during development.
• Ensure MySQL server is running and accessible.

Key Takeaways

Add spring-boot-starter-data-jpa and mysql-connector-java dependencies to your project.

Configure database connection properties correctly in application.properties.

Use the correct JDBC URL format and driver class name for MySQL.

Define JPA entities and repositories to interact with the database.

Check MySQL server status and credentials to avoid connection errors.