Mybatis-plus 使用技巧

文档指引  https://baomidou.com/

I. 环境

本文使用 JDK8 SpringBoot 版本为 2.2.5.RELEASE， mybatis-plus 版本为 3.2.1，数据库为 mysql 8+

2.依赖

<dependency>

   <groupId>mysql</groupId>

   <artifactId>mysql-connector-java</artifactId>

   <version>5.1.47</version>

</dependency>

<dependency>

   <groupId>org.springframework.boot</groupId>

   <artifactId>spring-boot-starter-test</artifactId>

   <scope>test</scope>

</dependency>

<dependency>

   <groupId>com.baomidou</groupId>

   <artifactId>mybatis-plus-boot-starter</artifactId>

   <version>3.4.2</version>

</dependency>

<dependency>

   <groupId>junit</groupId>

   <artifactId>junit</artifactId>

   <version>4.12</version>

</dependency>

3.常用方法

3.1查询

selectById

User selectById = UserMapper.selectById(id);

selectList

List<User> selectList = UserMapper.selectList(new LambdaQueryWrapper<User>()
        .eq(User::getParentId, id)
        .eq(User::getDelFlag, DelFlagEnums.NO_DELETE.code()));

selectBatchIds

selectByMap

3.2插入

insert

UserMapper.insert(user);

3.3修改更新

updatebyId

UserMapper.updatebyId(user);

3.4删除

deleteById