Sequelize - 聚合函数多对多

Question

我与organizaiton_member和user表之间的联结organization存在多对多关系。我正在尝试创建一个查询，计算organization_id与特定整数匹配的user_id的数量。我结束时的预期结果是一行，user_ids的总数为一列，organization_Id为第二列。我认为我可以通过以下查询实现此目的，但是我收到错误Unhandled rejection SequelizeDatabaseError: column "user.user_id" must appear in the GROUP BY clause or be used in an aggregate function。是否有必要这样做？很抱歉，缺乏使用SQL涉及聚合和多对多的经验。

查询：

models.User.findAll({
        attributes: [[sequelize.fn('COUNT', sequelize.col('user.user_id')), 'user_count']],
        include: [{
            model: models.Organization,
            where: {
                organizationId: req.session.organizationId
            },
            attributes: ['organization_id'],
            group: ['organiztion.organization_id']
        }],
    })

用户架构：

user_id
first_name
last_name
email

组织架构：

organization_id
org_name

Organization_Member架构：

user_id
organization_id

SQL生成：

SELECT "user"."user_id"                                      AS "userId", 
       Count("user"."user_id")                               AS "user_count", 
       "organizations"."organization_id"                     AS 
       "organizations.organizationId", 
       "organizations"."organization_id"                     AS 
       "organizations.organization_id", 
       "organizations.organization_member"."created_at"      AS 
       "organizations.organization_member.created_at", 
       "organizations.organization_member"."updated_at"      AS 
       "organizations.organization_member.updated_at", 
       "organizations.organization_member"."user_id"         AS 
       "organizations.organization_member.user_id", 
       "organizations.organization_member"."organization_id" AS 
       "organizations.organization_member.organization_id" 
FROM   "user" AS "user" 
       INNER JOIN ("organization_member" AS "organizations.organization_member" 
                   INNER JOIN "organization" AS "organizations" 
                           ON "organizations"."organization_id" = 
"organizations.organization_member"."organization_id") 
ON "user"."user_id" = "organizations.organization_member"."user_id" 
AND "organizations"."organization_id" = 1;