AbstractWrapper

1、ge、gt、le、lt、isNull、isNotNull

@Test
public void testDelete() {
　　QueryWrapper<User> queryWrapper = new QueryWrapper<>();
　　queryWrapper
　　 .isNull("name")
 　　.ge("age", 12)
　　 .isNotNull("email");
　　int result = userMapper.delete(queryWrapper);
　　System.out.println("delete return count = " + result);
}

 SQL：UPDATE user SET deleted=1 WHERE deleted=0 AND name IS NULL AND age >= ? AND email
 IS NOT NULL

2、eq、ne

@Test
public void testSelectOne() {
    QueryWrapper<User> queryWrapper = new QueryWrapper<>();
    queryWrapper.eq("name", "Tom");
    User user = userMapper.selectOne(queryWrapper);
    System.out.println(user);
} 

 SELECT id,name,age,email,create_time,update_time,deleted,version FROM user WHERE deleted=0

 AND name = ?

 

3、between、notBetween

@Test
public void testSelectCount() {
    QueryWrapper<User> queryWrapper = new QueryWrapper<>();
    queryWrapper.between("age", 20, 30);
    Integer count = userMapper.selectCount(queryWrapper);
    System.out.println(count);
}

SELECT COUNT(1) FROM user WHERE deleted=0 AND age BETWEEN ? AND ?

4、allEq

@Test
public void testSelectList() {
    QueryWrapper<User> queryWrapper = new QueryWrapper<>();
    Map<String, Object> map = new HashMap<>();
    map.put("id", 2);
    map.put("name", "Jack");
    map.put("age", 20);
    queryWrapper.allEq(map);
    List<User> users = userMapper.selectList(queryWrapper);
    users.forEach(System.out::println);
}

SELECT id,name,age,email,create_time,update_time,deleted,version

FROM user WHERE deleted=0 AND name = ? AND id = ? AND age = ?

 

5、like、notLike、likeLeft、likeRight

 

@Test
public void testSelectMaps() {
    QueryWrapper<User> queryWrapper = new QueryWrapper<>();
    queryWrapper
    .notLike("name", "e")
    .likeRight("email", "t");
    List<Map<String, Object>> maps = userMapper.selectMaps(queryWrapper);//返回值是Map列表
    maps.forEach(System.out::println);
}

SELECT id,name,age,email,create_time,update_time,deleted,version
FROM user WHERE deleted=0 AND name NOT LIKE ? AND email LIKE ?

6、in、notIn、inSql、notinSql、exists、notExists

@Test
public void testSelectObjs() {
    QueryWrapper<User> queryWrapper = new QueryWrapper<>();
    //queryWrapper.in("id", 1, 2, 3);
    queryWrapper.inSql("id", "select id from user where id < 3");
    List<Object> objects = userMapper.selectObjs(queryWrapper);//返回值 是Object列表
    objects.forEach(System.out::println);
}

 SELECT id,name,age,email,create_time,update_time,deleted,version
 FROM user WHERE deleted=0 AND id IN (select id from user where id < 3)

 

7、or、and

@Test
public void testUpdate1() {
    //修改值
    User user = new User();
    user.setAge(99);
    user.setName("Andy");
    //修改条件
    UpdateWrapper<User> userUpdateWrapper = new UpdateWrapper<>();
    userUpdateWrapper
     .like("name", "h")
     .or()
     .between("age", 20, 30);
    int result = userMapper.update(user, userUpdateWrapper);
    System.out.println(result);
}

UPDATE user SET name=?, age=?, update_time=? WHERE deleted=0 AND name LIKE ? OR age

BETWEEN ? AND ?