mybatisPlus条件查询

mybatisPlus提供了wrapper条件查询的方法，可以实现各种各样的条件查询，下面给出一些常用的条件方法，如需用到其他的条件方法可以到官网中很容易找到；

1. eq(“name”, “老王”)—>name = ‘老王’
2. ne(“name”, “老王”)—>name <> ‘老王’
3. gt(“age”, 18)—>age > 18
4. ge(“age”, 18)—>age >= 18
5. lt(“age”, 18)—>age < 18
6. le(“age”, 18)—>age <= 18
7. like(“name”, “王”)—>name like ‘%王%’
8. likeLeft(“name”, “王”)—>name like ‘%王’
9. isNull(“name”)—>name is null
10. in(“age”,{1,2,3})—>age in (1,2,3)
11. groupBy(“id”, “name”)—>group by id,name
12. orderByAsc(“id”, “name”)—>order by id ASC,name ASC
13. orderByDesc(“id”, “name”)—>order by id DESC,name DESC
14. and(i -> i.eq(“name”, “李白”).ne(“status”, “活着”))—>and (name = ‘李白’ and status <> ‘活着’)

使用方法

@Test
void testDeleted(){
    User user=userMapper.selectById(1);
    QueryWrapper wrapper=  new QueryWrapper<User>();
    wrapper.eq("id",1);
    List<User> list=userMapper.selectList(wrapper);
    list.forEach(System.out::println);
}