MyBatis-Plus is a powerful enhancement framework for MyBatis that automates common CRUD operations, significantly reducing development time. It integrates seamlessly without altering existing MyBatis configurations, providing a smooth experience with minimal performance overhead.

Key Features

• Non-Invasive Design: Enhances MyBatis functionality without modifying core behavior, ensuring compatibility with existing projects.
• Efficient CRUD Operations: Built-in generic Mapper and Service interfaces automate standard database operations with minimal configuration.
• Lambda Support: Enables type-safe query construtcion using lambda expressions, eliminating field name errors.
• Primary Key Generation: Supports multiple strategies including distributed unique ID generation via Sequence.
• ActiveRecord Pattern: Allows entities to inherit from Model class for direct CRUD operations.
• Global Operations: Provides reusable global methods for common tasks.
• Code Generator: Quickly generates Model, Mapper, Service, and Controller code via Maven plugin or standalone tool.
• Built-in Pagination: Database-agnostic pagination plugin smiplifies paging queries.
• Performance Analysis: Outputs SQL statements and execution times to identify slow queries.
• SQL Interceptor: Prevents accidental full-table updates or deletes with configurable rules.

Quick Setup Guide

1. Add Dependencies Include the following in your pom.xml:

   <dependency>
       <groupId>mysql</groupId>
       <artifactId>mysql-connector-java</artifactId>
       <version>8.0.27</version>
   </dependency>
   <dependency>
       <groupId>org.projectlombok</groupId>
       <artifactId>lombok</artifactId>
       <optional>true</optional>
   </dependency>
   <dependency>
       <groupId>com.baomidou</groupId>
       <artifactId>mybatis-plus-boot-starter</artifactId>
       <version>3.0.3</version>
   </dependency>
   

2. Database Setup Create a database and table:

   CREATE DATABASE demo_db;
   USE demo_db;
   CREATE TABLE employee (
       id BIGINT PRIMARY KEY COMMENT 'Primary Key',
       full_name VARCHAR(30) COMMENT 'Employee Name',
       years INT COMMENT 'Age',
       contact_email VARCHAR(50) COMMENT 'Email Address'
   );
   INSERT INTO employee (id, full_name, years, contact_email) VALUES
   (1, 'Alice', 25, 'alice@example.com'),
   (2, 'Bob', 30, 'bob@example.com'),
   (3, 'Charlie', 28, 'charlie@example.com');
   

3. Application Configuration Configure application.properties:

   spring.datasource.url=jdbc:mysql://localhost:3306/demo_db?useSSL=false&serverTimezone=UTC
   spring.datasource.username=db_user
   spring.datasource.password=db_password
   

Implementation Example

1. Define Entity Class

   import lombok.Data;
   @Data
   public class Employee {
       private Long id;
       private String fullName;
       private Integer years;
       private String contactEmail;
   }
   

2. Create Mapper Interface

   import com.baomidou.mybatisplus.core.mapper.BaseMapper;
   import org.apache.ibatis.annotations.Mapper;
   @Mapper
   public interface EmployeeMapper extends BaseMapper<Employee> {}
   

3. Enable Mapper Scanning Add to your main application class:

   import org.mybatis.spring.annotation.MapperScan;
   import org.springframework.boot.SpringApplication;
   import org.springframework.boot.autoconfigure.SpringBootApplication;
   @MapperScan("com.example.mapper")
   @SpringBootApplication
   public class Application {
       public static void main(String[] args) {
           SpringApplication.run(Application.class, args);
       }
   }
   

4. Execute Queries

   import org.springframework.beans.factory.annotation.Autowired;
   import org.springframework.boot.test.context.SpringBootTest;
   import org.junit.jupiter.api.Test;
   import java.util.List;
   @SpringBootTest
   public class DatabaseTest {
       @Autowired
       private EmployeeMapper dataMapper;
       @Test
       public void fetchAllRecords() {
           List<Employee> records = dataMapper.selectList(null);
           records.forEach(System.out::println);
       }
   }