SELECT * FROM `user` WHERE sex = '0' and (id = 1 or id = 2 or id =3)
//或者
SELECT * FROM `user` WHERE sex = '0' and id IN(1,2,3)

private List<Integer> ids;

<!-- sql片段 
        建议：对单表进行sql片段的抽取，方便重用
            抽取时不包含where
     -->
     <sql id="findUserSql">
        <if test="userCustomer!=null">
                <if test="userCustomer.sex!=null and userCustomer.sex!=''">
                    and user.sex=#{userCustomer.sex}
                </if>
                <if test="userCustomer.address!=null and userCustomer.address!=''">
                    and user.address like '$%{userCustomer.address}%'
                </if>
                <if test="ids!=null">
                    <!-- collection:指定输入对象的集合属性
                        item:每一个遍历生成的对象
                        open:开始遍历串拼接串
                        close:结束拼接时遍历的串
                        separator:遍历的两个对象中间需要拼接的串
                     -->
                     <!-- 使用实现这个串的拼接and(id = 1 or id = 2 or id =3) -->
                    <foreach collection="ids" item="i_id" open="and(" close=")" separator="or">
                        id = #{i_id}
                    </foreach>
                </if>
        </if>
     </sql>

<!-- 使用实现这个串的拼接 and id IN(1,2,3) -->
<foreach collection="ids" item="i_id" open="and id IN(" close=")" separator=",">
    #{i_id}
</foreach>

@Test
    public void findUserCount() throws Exception{
        SqlSession sqlSession = sqlSessionFactory.openSession();
        UserMapper usermapper = sqlSession.getMapper(UserMapper.class);
        //构建一个包装类
        UserQueryVo userQueryVo = new UserQueryVo();
        //构建一个增强类
        UserCustomer userCustomer = new UserCustomer();
        userCustomer.setAddress("明月");
        //包装类包装这增强类作为查询条件
        userQueryVo.setUserCustomer(userCustomer);
        ArrayList<Integer> ids = new ArrayList<Integer>();
        ids.add(1);
        ids.add(2);
        ids.add(3);
        userQueryVo.setIds(ids);
        List<UserCustomer> userList = usermapper.fingUserList(userQueryVo);
        sqlSession.close();
        for (UserCustomer user : userList) {
            System.out.println(user);
        }
    }