Database 有没有办法显示某一业务类型的前10名平均评级？

我的数据库方案中有以下表格

CREATE TABLE public.organization_rating
(
    rating integer NOT NULL,
    user_id integer NOT NULL,
    organization_id integer NOT NULL,
    CONSTRAINT organization_rating_pkey PRIMARY KEY (user_id, organization_id),
    CONSTRAINT user_id FOREIGN KEY (user_id)
        REFERENCES public.users (user_id) MATCH SIMPLE
        ON UPDATE CASCADE
        ON DELETE CASCADE,
    CONSTRAINT stars CHECK (rating >= 1 AND rating < 5)
)

我想实现一个查询，该查询提供以下信息：

每种业务类型的前10名组织评级 每个业务阶段前10名组织 评级最差的前三名组织 由于查询看起来很相似，我只需要订购DESC或ASC，这取决于需求，我只需要一个查询就可以工作，我将使用另外两个查询。我尝试实现此查询：

CREATE TABLE public.organization
(
    org_id integer NOT NULL DEFAULT nextval('organization_org_id_seq'::regclass),
    name character varying(90) COLLATE pg_catalog."default" NOT NULL,
    description character varying(90) COLLATE pg_catalog."default" NOT NULL,
    email text COLLATE pg_catalog."default" NOT NULL,
    phone_number character varying COLLATE pg_catalog."default" NOT NULL,
    bt_id integer NOT NULL,
    bs_id integer NOT NULL,
    CONSTRAINT organization_pkey PRIMARY KEY (org_id),
    CONSTRAINT bs_id FOREIGN KEY (bs_id)
        REFERENCES public.business_step (bs_id) MATCH SIMPLE
        ON UPDATE CASCADE
        ON DELETE CASCADE
        NOT VALID,
    CONSTRAINT bt_id FOREIGN KEY (bt_id)
        REFERENCES public.business_type (bt_id) MATCH SIMPLE
        ON UPDATE CASCADE
        ON DELETE CASCADE
        NOT VALID
)

with average_rating as (
    SELECT organization_id as Organization_ID, ROUND(AVG(rating)) as Rating
    FROM organization_rating
    GROUP BY organization_id
),
ordered_data as (
  select org_id, bt_id, rating, row_number() over (partition by bt_id order by rating desc) rank
  from average_rating r
    join organization o on o.org_id = r.organization_id
    where bt_id = 1
  order by bt_id, rating desc 
)
select  org_id, bt_id, rating
from ordered_data
where rank <= 10

以下是我的选择声明：

SELECT O.org_id, O.bt_id, R.rating
FROM public.organization as O
INNER JOIN public.organization_rating as R ON O.org_id = R.organization_id
WHERE bt_id=1
GROUP by org_id, bt_id, rating
ORDER BY ROUND(AVG(rating)) DESC LIMIT 10

但结果如下：

似乎有一个错误，不同的组织被复制。这些是被复制组织的实际平均值：

及

为什么要复制组织id

---

提前感谢。

您看到重复记录的原因是因为组织中的评级是按用户进行的。可以有多个用户对一个组织进行评级。您应该首先计算平均评级，然后加入organization表

对于bt_id=1，您可以执行以下操作：

with average_rating as (
    select organization_id as org_id, avg(rating) as avg_rating
    from organization_rating r
    group by org_id
)
select org_id, bt_id, avg_rating
from average_rating r
  join organization o on o.org_id = r.org_id
where r.bt_id = 1
order by avg_rating desc limit 10; 

如果要在单个查询中获取所有数据，可以使用窗口函数：

with average_rating as (
    select organization_id as org_id, avg(rating) as avg_rating
    from organization_rating r
    group by org_id
),
ordered_data as (
  select org_id, bt_id, avg_rating, row_number() over (partition by bt_id order by avg_rating desc) rank
  from average_rating r
    join organization o on o.org_id = r.org_id
  order by bt_id, avg_rating desc 
)
select  org_id, bt_id, avg_rating
from ordered_data
where rank <= 10

---

多亏了mihai_f87，我才能够构建这个查询：

CREATE TABLE public.organization
(
    org_id integer NOT NULL DEFAULT nextval('organization_org_id_seq'::regclass),
    name character varying(90) COLLATE pg_catalog."default" NOT NULL,
    description character varying(90) COLLATE pg_catalog."default" NOT NULL,
    email text COLLATE pg_catalog."default" NOT NULL,
    phone_number character varying COLLATE pg_catalog."default" NOT NULL,
    bt_id integer NOT NULL,
    bs_id integer NOT NULL,
    CONSTRAINT organization_pkey PRIMARY KEY (org_id),
    CONSTRAINT bs_id FOREIGN KEY (bs_id)
        REFERENCES public.business_step (bs_id) MATCH SIMPLE
        ON UPDATE CASCADE
        ON DELETE CASCADE
        NOT VALID,
    CONSTRAINT bt_id FOREIGN KEY (bt_id)
        REFERENCES public.business_type (bt_id) MATCH SIMPLE
        ON UPDATE CASCADE
        ON DELETE CASCADE
        NOT VALID
)

with average_rating as (
    SELECT organization_id as Organization_ID, ROUND(AVG(rating)) as Rating
    FROM organization_rating
    GROUP BY organization_id
),
ordered_data as (
  select org_id, bt_id, rating, row_number() over (partition by bt_id order by rating desc) rank
  from average_rating r
    join organization o on o.org_id = r.organization_id
    where bt_id = 1
  order by bt_id, rating desc 
)
select  org_id, bt_id, rating
from ordered_data
where rank <= 10

通过这个查询，我可以搜索每种业务类型的前10个组织

输出

---

当我运行查询时，会出现以下消息：错误：列引用组织id不明确第7行：选择组织id、bt id、平均评级、部分上的行号。。。