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));
}总结
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