QueryWrapper常用方法__沈_querywrapper

网络 02-07 3319

QueryWrapper常用方法

MybatisPlus 使用QueryWrapper测试用例一、ge、gt、le、lt、isNull、isNotNull @Test public void testQuery() { 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); } 二、eq、ne @Test public void testSelectOne() { QueryWrapper<User> queryWrapper = new QueryWrapper<>(); queryWrapper.eq("name", "Tom"); Useruser = userMapper.selectOne(queryWrapper);//只能返回一条记录，多余一条则抛出异常 System.out.println(user); } 三、between、notBetween @Test public void testSelectCount() { QueryWrapper<User> queryWrapper = new QueryWrapper<>(); queryWrapper.between("age", 20, 30); Integer count = userMapper.selectCount(queryWrapper); //返回数据数量 System.out.println(count); } 四、like、notLike、likeLeft、likeRight @Test public void testSelectMaps() { QueryWrapper<User> queryWrapper = new QueryWrapper<>(); queryWrapper .select("name", "age") .like("name", "e") .likeRight("email", "5"); List<Map<String, Object>> maps = userMapper.selectMaps(queryWrapper);//返回值是Map列表 maps.forEach(System.out::println); } 五、orderBy、orderByDesc、orderByAsc @Test public void testSelectListOrderBy() { QueryWrapper<User> queryWrapper = new QueryWrapper<>(); queryWrapper.orderByDesc("age", "id"); List<User>users = userMapper.selectList(queryWrapper); users.forEach(System.out::println); } 六、插入insert @Test public void save() { User user = new User(); user.setAge(23); user.setEmail("344"); user.setName("test"); // 1.使用service新增 userService.save(user); // 2.使用mapper 新增 userMapper.insert(user); } 七、删除remove @Test public void delete() { // 根据条件删除 userService.remove(Wrappers.<User>query().lambda().eq(User::getAge, 3)); } 八、修改update @Test public void update() { User user = new User(); user.setAge(23); user.setEmail("344"); user.setName("test333"); UpdateWrapper<User> updateWrapper = new UpdateWrapper<>(); updateWrapper.eq("id","1"); // 1.user 中封装修改的属性值， updateWrapper 中封装修改的条件参数值 userService.update(user,updateWrapper); // 2.根据条件修改对应的参数属性值 userService.update(Wrappers.<User>update().lambda().set(User::getName, "2").eq(User::getAge, 23));　　　　 // 3.判断参数是否为空,并进行修改　　　　 String name = "name";　　　　 userService.update(Wrappers.<User>update().lambda().set(StringUtils.isNotBlank(name),User::getName, name).eq(User::getAge, 23)); }