mybatis foerach多条件查询

比如,我们要查找很多id的user1,31…
解释下foreach中各个参数意思:

• foreach元素的属性主要有 item，index，collection，open，separator，close。

1. item表示集合中每一个元素进行迭代时的别名，

2. index指 定一个名字，用于表示在迭代过程中，每次迭代到的位置，

3. open表示该语句以什么开始，

4. separator表示在每次进行迭代之间以什么符号作为分隔 符，

5. close表示以什么结束。
   UserMapper.xml

<select id="findUserByMoreId"  parameterType="list" resultType="com.company.User">
        select id,name,password from user where  id in
        <foreach collection="list" item="item" separator="," open="(" close=")" index="index">
            #{item}
        </foreach>
    </select>

照着写就行,需要修改自己参数.
测试类:

 @Test
    public void findUserByMoreId () throws IOException {
        InputStream is = Resources.getResourceAsStream("SqlMapConfig.xml");
        //建立会话工厂
        SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(is);
        SqlSession sqlSession = sqlSessionFactory.openSession();
        UserMapper mapper = sqlSession.getMapper(UserMapper.class);
        List<Integer> list= Arrays.asList(1,31);
        List<User> userList=mapper.findUserByMoreId(list);
        System.out.println(userList);
        sqlSession.close();

    }

接口mapper:

 List<User> findUserByMoreId (List<Integer> list);
 

结果显示:

2019-05-30 08:59:48,726 [main] DEBUG [com.mapper.UserMapper] - Cache Hit Ratio [com.mapper.UserMapper]: 0.0
2019-05-30 08:59:49,549 [main] DEBUG [com.mapper.UserMapper.findUserByMoreId] - ==>  Preparing: select id,name,password from user where id in ( ? , ? ) 
2019-05-30 08:59:49,675 [main] DEBUG [com.mapper.UserMapper.findUserByMoreId] - ==> Parameters: 1(Integer), 31(Integer)
2019-05-30 08:59:49,744 [main] DEBUG [com.mapper.UserMapper.findUserByMoreId] - <==      Total: 2
[User{id=1, name='帅帅', password='帅帅', aClass=null, listTea=null}
, User{id=31, name='jok1', password='jok1', aClass=null, listTea=null}
]

希望对大家有帮助!!!