Mybatis-plus入门学习]

需要的数据库建表语句:

#创建用户表
CREATE TABLE user (
    id BIGINT(20) PRIMARY KEY NOT NULL COMMENT '主键',
    name VARCHAR(30) DEFAULT NULL COMMENT '姓名',
    age INT(11) DEFAULT NULL COMMENT '年龄',
    email VARCHAR(50) DEFAULT NULL COMMENT '邮箱',
    manager_id BIGINT(20) DEFAULT NULL COMMENT '直属上级id',
    create_time DATETIME DEFAULT NULL COMMENT '创建时间',
    CONSTRAINT manager_fk FOREIGN KEY (manager_id)
        REFERENCES user (id)
)  ENGINE=INNODB CHARSET=UTF8;

#初始化数据：
INSERT INTO user (id, name, age, email, manager_id
    , create_time)
VALUES (1087982257332887553, '大boss', 40, 'boss@baomidou.com', NULL
        , '2019-01-11 14:20:20'),
    (1088248166370832385, '王天风', 25, 'wtf@baomidou.com', 1087982257332887553
        , '2019-02-05 11:12:22'),
    (1088250446457389058, '李艺伟', 28, 'lyw@baomidou.com', 1088248166370832385
        , '2019-02-14 08:31:16'),
    (1094590409767661570, '张雨琪', 31, 'zjq@baomidou.com', 1088248166370832385
        , '2019-01-14 09:15:15'),
    (1094592041087729666, '刘红雨', 32, 'lhm@baomidou.com', 1088248166370832385
        , '2019-01-14 09:48:16');

使用的是springboot项目:

配置文件:

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://127.0.0.1:3306/mybatis-plus?serverTimezone=UTC&useUnicode=true&useSSL=false&characterEncoding=utf8
    username: root
    password: root
logging:
  level:
    root: debug

  pattern:
    console: '%p%m%n'

#mapper的存放路径
mybatis-plus:
  mapper-locations: mapper/*

创建的实体类

public class User extends Model<User> {

    //主键
    private Long id;
    //姓名
    @TableField(condition = SqlCondition.LIKE)
    private String name;
    //邮箱
    private String email;
    //年龄
    private Integer age;
    //直属上级
    private Long managerId;
    //创建时间
    private LocalDateTime createTime;

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", email='" + email + '\'' +
                ", age=" + age +
                ", managerId=" + managerId +
                ", createTime=" + createTime +
                '}';
    }

    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;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    public Long getManagerId() {
        return managerId;
    }

    public void setManagerId(Long managerId) {
        this.managerId = managerId;
    }

    public LocalDateTime getCreateTime() {
        return createTime;
    }

    public void setCreateTime(LocalDateTime createTime) {
        this.createTime = createTime;
    }
}

mapper接口

@Repository
public interface UserMapper extends BaseMapper<User> {
    //@Select("select * from user ${ew.customSqlSegment}")
   // List<User> selectAll(@Param(Constants.WRAPPER) QueryWrapper<User> Wrapper);

    IPage<User> selectUserByPage(Page<User>page,@Param(Constants.WRAPPER) QueryWrapper<User> Wrapper);

    List<User> selectAll(@Param(Constants.WRAPPER) QueryWrapper<User> Wrapper);
}

分页插件的配置:

@Configuration
public class MybatisPlusConfig {
    @Bean
    public PaginationInterceptor paginationInterceptor() {
        return new PaginationInterceptor();
    }

}

service层接口:

public interface UserService extends IService<User> {

}

service层实现类:

@Service
public class UserService extends ServiceImpl<UserMapper, User> implements com.qingmu.mybatisplus.service.UserService {

}

启动类进行的配置

@SpringBootApplication
@MapperScan("com.qingmu.mybatisplus.dao")
public class MybatisplusApplication {

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

}

mapper.xml文件:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.qingmu.mybatisplus.dao.UserMapper">
    <select id="selectAll" resultType="com.qingmu.mybatisplus.entity.User">
select * from user ${ew.customSqlSegment}
</select>
    <select id="selectUserByPage" resultType="com.qingmu.mybatisplus.entity.User">
select * from user ${ew.customSqlSegment}
</select>

</mapper>

测试方法:

@SpringBootTest
public class UserTest {

    @Autowired
    private UserMapper userMapper;

    @Test
    public void select() {
        List<User> users = userMapper.selectList(null);
        users.forEach(user -> System.out.println(user.toString()));
    }

    @Test
    public void insertTest() {
        User user = new User();
        user.setName("网台风");
        user.setEmail(null);
        user.setAge(18);
        user.setManagerId(1196025318649888768L);
        user.setCreateTime(LocalDateTime.now());
        int insert = userMapper.insert(user);
        System.out.println(insert);
    }
    @Test
    public void insertTest2() {
        User user = new User();
        user.setName("网台风");
        user.setEmail(null);
        user.setAge(18);
        user.setManagerId(1196025318649888768L);
        user.setCreateTime(LocalDateTime.now());
        boolean insert = user.insert();
        System.out.println(insert);
    }

    @Test
    public void selectById() {
        User user = userMapper.selectById(1196025318649888768L);
        System.out.println(user.toString());
    }

    @Test
    public void selectIds() {
        List<Long> longList = Arrays.asList(1196025318649888768L, 1197173809883381760L);
        List<User> users = userMapper.selectBatchIds(longList);
        users.forEach(user -> System.out.println(user.toString()));
    }

    @Test
    public void selectByMap() {
        HashMap<String, Object> map = new HashMap<>();
        map.put("name", "王天风");
        List<User> users = userMapper.selectByMap(map);
        for (User user : users) {
            System.out.println(user.toString());
        }
    }

    //名字中包含雨,并且年龄小于40
    @Test
    public void selectByWraper() {
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        wrapper.like("name", "雨");
        wrapper.lt("age", 40);
        List<User> users = userMapper.selectList(wrapper);
        for (User user : users) {
            System.out.println(user.toString());
        }
    }

    //名字中包含雨年并且龄大于等于20且小于等于40并且email不为空
    @Test
    public void test2() {
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        wrapper.like("name", "雨")
                .between("age", 20, 40)
                .isNotNull("email");
        List<User> users = userMapper.selectList(wrapper);
        for (User user : users) {
            System.out.println(user.toString());
        }
    }

    //名字为王姓或者年龄大于等于25，按照年龄降序排列，年龄相同按照id升序排列
    @Test
    public void test3() {
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        wrapper.likeRight("name", "王")
                .or().ge("age", 25)
                .orderByDesc("age").orderByAsc("id");
        List<User> users = userMapper.selectList(wrapper);
        for (User user : users) {
            System.out.println(user.toString());
        }
    }

    //创建日期为2019年2月14日并且直属上级为名字为王姓
    @Test
    public void test4() {
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        wrapper.apply("date_format(create_time,'%Y-%m-%d')={0}", "2019-02-14")
                .inSql("manager_id", "select id from user where name like '王%'");
        List<User> users = userMapper.selectList(wrapper);
        for (User user : users) {
            System.out.println(user.toString());
        }
    }

    //名字为王姓并且（年龄小于40或邮箱不为空）
    @Test
    public void test5() {
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        wrapper.likeRight("name", "王")
                .and(wq -> wq.lt("age", 40).or().isNotNull("email"));
        List<User> users = userMapper.selectList(wrapper);
        for (User user : users) {
            System.out.println(user.toString());
        }
    }

    //6.名字为王姓或者（年龄小于40并且年龄大于20并且邮箱不为空）
    @Test
    public void test6() {
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        wrapper.likeRight("name", "王")
                .or(wq -> wq.lt("age", 40).ge("age", 20).isNotNull("email"));
        List<User> users = userMapper.selectList(wrapper);
        for (User user : users) {
            System.out.println(user.toString());
        }
    }

    //7、（年龄小于40或邮箱不为空）并且名字为王姓
    @Test
    public void test7() {
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        wrapper.nested(qw -> qw.lt("age", 40).isNotNull("email")).likeRight("name", "王");
        List<User> users = userMapper.selectList(wrapper);
        for (User user : users) {
            System.out.println(user.toString());
        }
    }

    //年龄为30、31、34、35
    @Test
    public void test8() {
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        wrapper.in("age", Arrays.asList(18, 31, 30, 34, 35));
        List<User> users = userMapper.selectList(wrapper);
        for (User user : users) {
            System.out.println(user.toString());
        }
    }

    @Test
    public void test9() {
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        wrapper.in("age", Arrays.asList(18, 31, 30, 34, 35)).last("limit 1");
        List<User> users = userMapper.selectList(wrapper);
        for (User user : users) {
            System.out.println(user.toString());
        }
    }

    //不列出全部字段
    @Test
    public void test10() {
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        wrapper.select("id", "name").in("age", Arrays.asList(18, 31, 30, 34, 35)).last("limit 1");
        List<User> users = userMapper.selectList(wrapper);
        for (User user : users) {
            System.out.println(user.toString());
        }
    }

    //不列出全部字段
    @Test
    public void test11() {
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        wrapper.select(User.class, info -> !info.getColumn().equals("create_time")
                && !info.getColumn().equals("manager_id")).in("age", Arrays.asList(18, 31, 30, 34, 35)).last("limit 1");
        List<User> users = userMapper.selectList(wrapper);
        for (User user : users) {
            System.out.println(user.toString());
        }
    }

    //condition条件
    @Test
    public void testCondition() {
        String name = "王";
        String email = "";
        condition(name, email);
    }

    private void condition(String name, String email) {
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        //需要六行,太麻烦
//        if(StringUtils.isNotBlank(name)){
//            wrapper.like("name",name);
//        }
//        if(StringUtils.isNotBlank(name)){
//            wrapper.like("name",name);
//        }
        wrapper.like(StringUtils.isNotBlank("name"), "name", name)
                .like(StringUtils.isNotBlank("email"), "email", email);
        List<User> users = userMapper.selectList(wrapper);
        for (User user : users) {
            System.out.println(user.toString());
        }
    }

    // 实体作为条件构造器构造方法的参数
    @Test
    public void test12() {
        User user1 = new User();
        user1.setName("刘红雨");
        user1.setAge(32);

        QueryWrapper<User> wrapper = new QueryWrapper<>(user1);
//    wrapper.select(User.class, info -> !info.getColumn().equals("create_time")
//            && !info.getColumn().equals("manager_id")).in("age", Arrays.asList(18, 31, 30, 34, 35)).last("limit 1");
        List<User> users = userMapper.selectList(wrapper);
        for (User user : users) {
            System.out.println(user.toString());
        }
    }

    //Alleq
    @Test
    public void test13() {
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        HashMap<String, Object> map = new HashMap<>();
        map.put("name", "王天风");
//        map.put("age", "25");
        map.put("age", null);
        wrapper.allEq(map);
        //如果为false,则会忽略为null的字段
//        wrapper.allEq(map,false);
        wrapper.allEq((k, v) -> !k.equals("name"), map);
        List<User> users = userMapper.selectList(wrapper);
        for (User user : users) {
            System.out.println(user.toString());
        }
    }

    @Test
    public void test14() {
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        wrapper.select("avg(age) avg_age", "min(age) min_age", "max(age) max_age").groupBy("manager_id")
                .having("sum(age)<{0}", 500);
        List<Map<String, Object>> users = userMapper.selectMaps(wrapper);
        System.out.println(users);
    }

    @Test
    public void test15() {
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        wrapper.select("avg(age) avg_age", "min(age) min_age", "max(age) max_age").groupBy("manager_id")
                .having("sum(age)<{0}", 500);
        List<Object> users = userMapper.selectObjs(wrapper);
        System.out.println(users);
    }

    @Test
    public void test16() {
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        wrapper.select("avg(age) avg_age", "min(age) min_age", "max(age) max_age").groupBy("manager_id")
                .having("sum(age)<{0}", 500);
        Integer count = userMapper.selectCount(wrapper);
        System.out.println(count);
    }

    @Test
    public void test17() {
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        wrapper.select("avg(age) avg_age", "min(age) min_age", "max(age) max_age").groupBy("manager_id")
                .having("sum(age)<{0}", 500);
        User user = userMapper.selectOne(wrapper);
        System.out.println(user);
    }

    @Test
    public void test18() {
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        wrapper.select("avg(age) avg_age", "min(age) min_age", "max(age) max_age").groupBy("manager_id")
                .having("sum(age)<{0}", 500);
        List<User> users = userMapper.selectAll(wrapper);
        System.out.println(users);
    }

    //分页
    @Test
    public void selectPage() {
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        wrapper.ge("age", 26);
        Page<User> page = new Page<>(1, 2);
//        IPage<User> userIPage = userMapper.selectPage(page, wrapper);
//        System.out.println("总条数"+userIPage.getTotal());
//        System.out.println("总页数"+userIPage.getPages());

        IPage<Map<String, Object>> userIPage = userMapper.selectMapsPage(page, wrapper);
        System.out.println("总条数" + userIPage.getTotal());
        System.out.println("总页数" + userIPage.getPages());
    }

    @Test
    public void selectPage2() {
        QueryWrapper<User> wrapper = new QueryWrapper<>();
        wrapper.ge("age", 26);
        Page<User> page = new Page<>(1, 2);
//        IPage<User> userIPage = userMapper.selectPage(page, wrapper);
//        System.out.println("总条数"+userIPage.getTotal());
//        System.out.println("总页数"+userIPage.getPages());

        IPage<User> userIPage = userMapper.selectUserByPage(page, wrapper);
        System.out.println("总条数" + userIPage.getTotal());
        System.out.println("总页数" + userIPage.getPages());
    }

    //更新
    @Test
    public void updateById() {
        User user = new User();
        user.setId(1087982257332887553L);
        user.setAge(26);
        int i = userMapper.updateById(user);
        System.out.println(i);
    }

    @Test
    public void updateWrapper1() {
        UpdateWrapper<User> wrapper = new UpdateWrapper<>();
        wrapper.eq("name", "李艺伟").eq("age", 28);
        User user = new User();
        user.setName("利益");
        int update = userMapper.update(user, wrapper);
        System.out.println("影响记录条数:" + update);
    }

    @Test
    public void updateWrapper2() {
        User user1 = new User();
        user1.setName("利益");

        UpdateWrapper<User> wrapper = new UpdateWrapper<>(user1);
//        wrapper.eq("name","李艺伟").eq("age",28);
        User user = new User();
        user.setName("利益");
        int update = userMapper.update(user, wrapper);
        System.out.println("影响记录条数:" + update);
    }

    @Test
    public void updateWrapper3() {
        UpdateWrapper<User> wrapper = new UpdateWrapper<>();
        wrapper.eq("name", "李艺伟")
                .eq("age", 28)
                .set("age", 29);
//        User user = new User();
//        user.setName("利益");
        int update = userMapper.update(null, wrapper);
        System.out.println("影响记录条数:" + update);
    }

    @Test
    public void updateLamda(){
        LambdaUpdateWrapper<User> lambdaUpdate = Wrappers.<User>lambdaUpdate();
        lambdaUpdate.eq(User::getName,"李艺伟").eq(User::getAge,"29").set(User::getAge,"30");
        int update = userMapper.update(null, lambdaUpdate);
        System.out.println(update);
    }

    @Test
    public void delete(){
        int i = userMapper.deleteById(1197191875728003073L);
        System.out.println(i);
    }

    @Test
    public void delete2(){
        HashMap<String, Object> map = new HashMap<>();
        map.put("name","网台风");
        map.put("age",18);

        int i = userMapper.deleteByMap(map);
        System.out.println(i);
    }
    @Test
    public void delete3(){
        int i = userMapper.deleteBatchIds(Arrays.asList(1197191725035073537L,1197191393303359489L));
        System.out.println(i);
    }
}

service层接口测试方法:

@SpringBootTest
@RunWith(SpringRunner.class)
public class ServiceTest {

    @Autowired
    private UserService userService;

    @Test
    public void getOne() {
        User one = userService.getOne(Wrappers.<User>lambdaQuery().gt(User::getAge, "20"),false);

        System.out.println(one);
    }

    @Test
    public void Batch() {
        User user = new User();
        user.setName("蓄力");
        user.setAge(18);

        User user2 = new User();
        user.setName("蓄力2");
        user.setAge(28);

        List<User> users = Arrays.asList(user, user2);
        boolean b = userService.saveBatch(users);
        System.out.println(b);
    }

    @Test
    public void chain(){
        List<User> users = userService.lambdaQuery().gt(User::getAge, 25).like(User::getName, "雨").list();
        users.forEach(System.out::println);
    }

    @Test
    public void chain2(){
        boolean update = userService.lambdaUpdate().eq(User::getAge, 25).set(User::getAge, 26).update();
        System.out.println(update);
    }

    @Test
    public void chain3(){
        boolean update = userService.lambdaUpdate().eq(User::getAge, 24).remove();
        System.out.println(update);
    }
}