Core Capabilities

• Seamless Enhancement: Augments MyBatis without altering its original mechanics, ensuring frictionless adoption.
• Minimal Overhead: Basic CRUD operations are automatically injected upon startup, allowing direct object-oriented manipulation with negligible performance cost.
• Robust CRUD: Provides built-in generic Mapper and Service interfaces, enabling single-table operations with minimal setup, alongside versatile conditional wrappers.
• Lambda Expressions: Enables type-safe query formulation through Lambda expressions, preventing field name mismatches.
• Key Generation: Offers multiple primary key strategies, including distributed unique ID generators.
• ActiveRecord: Supports ActiveRecord patterns where entities inherit the Model class to execute CRUD operations directly.
• Global Method Injection: Allows defining custom universal methods that are injected globally.
• Code Scaffolding: Includes a code generator to rapidly produce Mapper, Model, Service, and Controller layers.
• Physical Pagination: Features a built-in physical pagination plugin supporting numerous databases (MySQL, Oracle, PostgreSQL, etc.), making paginated queries identical to standard list queries.
• Performance Analysis: Incorporates a plugin to log SQL execution times, facilitating the identification of slow queries.
• Preventative Interception: Smart blocker for full-table delete or update operations to prevent accidental data destruction.

Database Initialization

DROP TABLE IF EXISTS `app_user`;CREATE TABLE `app_user`(    user_id BIGINT NOT NULL COMMENT 'Primary identifier',    full_name VARCHAR(30) NULL DEFAULT NULL COMMENT 'Full name',    user_age INT NULL DEFAULT NULL COMMENT 'Age',    contact_email VARCHAR(50) NULL DEFAULT NULL COMMENT 'Email address',    PRIMARY KEY (user_id));DELETE FROM `app_user`;INSERT INTO `app_user` (user_id, full_name, user_age, contact_email) VALUES(1, 'Alice', 28, 'alice@example.org'),(2, 'Bob', 35, 'bob@example.org'),(3, 'Charlie', 22, 'charlie@example.org');

Maven Dependencies

<dependency>    <groupId>com.baomidou</groupId>    <artifactId>mybatis-plus-boot-starter</artifactId>    <version>3.5.7</version></dependency>

Application Configuration

spring:  datasource:    driver-class-name: com.mysql.cj.jdbc.Driver    url: jdbc:mysql://localhost:3306/app_db?serverTimezone=UTC    username: admin    password: secretPasswordmybatis-plus:  mapper-locations: classpath*:mapper/**/*.xml  configuration:    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

Entity Definition

@Data@TableName("app_user")public class AppUser {    @TableId("user_id")    private Long userId;    @TableField("full_name")    private String fullName;    @TableField("user_age")    private Integer userAge;    @TableField("contact_email")    private String contactEmail;}

Mapper Interface

public interface AppUserMapper extends BaseMapper<AppUser> {}

Proxy Configuration

Ensure the application main class is annotated to scan for mapper interfaces.

@SpringBootApplication@MapperScan("com.example.mapper")public class Application {    public static void main(String[] args) {        SpringApplication.run(Application.class, args);    }}

CRUD Verification

Fetching by Identifier

@SpringBootTestclass MybatisPlusIntegrationTests {    @Autowired    private AppUserMapper appUserMapper;    @Test    void fetchById() {        AppUser record = appUserMapper.selectById(1);        System.out.println(record);    }}

Inserting or Updating Records

@Testvoid addOrUpdateRecord() {    AppUser newUser = new AppUser();    newUser.setUserId(4L);    newUser.setFullName("David");    newUser.setUserAge(40);    newUser.setContactEmail("david@example.org");    appUserMapper.insertOrUpdate(newUser);}