Master MyBatis-Plus with Spring Boot: CRUD, Pagination & Multi-DataSource Guide

MyBatis-Plus Quick Start with Spring Boot

This article provides a step‑by‑step guide to integrate MyBatis‑Plus into a Spring Boot project, covering environment preparation, Maven dependencies, configuration of the data source, mapper scanning, and application startup.

Dependency and Configuration

<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>3.5.0</version>
</dependency>
...
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.27</version>
</dependency>

Configure the primary MySQL datasource and enable the dynamic‑datasource starter for master‑slave setups.

Entity Annotations

@TableName("user")
public class UserDO {
    @TableId(value = "id", type = IdType.AUTO)
    private Long id;
    @TableField("nickname")
    private String nickname;
    @TableField("sex")
    private SexEnum sex;
    @TableField(value = "create_time", fill = FieldFill.INSERT)
    private LocalDateTime createTime;
}

Common MyBatis‑Plus annotations such as @TableName, @TableId, @TableField, and @TableLogic are explained.

CRUD Operations

Service interfaces extend IService<UserDO> and implementations extend ServiceImpl<UserMapper,UserDO>. Mapper interfaces extend BaseMapper<UserDO>, providing out‑of‑the‑box CRUD methods.

Pagination

@Bean
public MybatisPlusInterceptor mybatisPlusInterceptor() {
    MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
    interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
    return interceptor;
}

Logical Delete

mybatis-plus:
  global-config:
    db-config:
      logic-delete-field: isDelete
      logic-delete-value: 1
      logic-not-delete-value: 0

Enum Mapping

public enum SexEnum implements IEnum<Integer> {
    MAN(1, "男"),
    WOMAN(2, "女");
    private final Integer code;
    private final String name;
    @Override public Integer getValue() { return code; }
    public String getName() { return name; }
}

Automatic Field Filling

@Component
public class MyMetaObjectHandler implements MetaObjectHandler {
    @Override
    public void insertFill(MetaObject metaObject) {
        this.strictInsertFill(metaObject, "createTime", LocalDateTime.class, LocalDateTime.now());
    }
    @Override
    public void updateFill(MetaObject metaObject) {
        this.strictUpdateFill(metaObject, "updateTime", LocalDateTime.class, LocalDateTime.now());
    }
}

Multi‑DataSource Support

Configuration examples for master‑slave, multiple databases, and mixed setups are shown, and the @DS annotation can be placed on classes or methods to select a datasource.

Testing

A sample controller demonstrates create, update, delete, list and paginated queries, confirming that the integration works as expected.