我该怎么办？ sequelize isull

Question

[表格] USER_INFO

user_id  |  user_name
a123     |  facebook
b123     |  google
c123     |  NULL

[查询]

select isnull(user_name, user_id) as user_name from USER_INFO

[结果]

user_name
facebook
google
c123

[sequelize] ???????

User.findAll({attributes: [
    user_id
    ,user_name
 ]
});

我想要相同的结果，查询=序列化。。