Sql 如何为表中的每个公司只获得一个结果？

我有查询，但现在我需要将查询更改为数据库，以便在表

Price

中为每个公司只获得一个结果

为此，我添加了按p.id\U公司分组的行

，然后得到下一个查询：

SELECT TOP 20 
  p.id_price as p_id_price, 
  p.id_service as p_id_service, 
  p.name as p_name, 
  p.name_original as p_name_original, 
  p.id_producer_country as p_id_producer_country, 
  p.id_firm as p_id_firm, 
  f.name as f_name, 
  f.address as f_address, 
  f.phone as f_phone, 
  city.name as city_name, 
  pc.name as pc_name 
FROM Price p 
left join Firm f 
  on f.id_service=p.id_service 
  AND f.id_city=p.id_city 
  AND f.id_firm=p.id_firm 
left join City city 
  on city.id_city = p.id_city 
left join Producer_country pc 
  on pc.id_producer_country = p.id_producer_country 
WHERE p.id_city='73041' 
  AND p.include='1' 
  AND p.blocked='0' 
  AND f.blocked='0' 
  AND ( f.name LIKE 'Окно%' COLLATE SQL_Latin1_General_Cp1251_CI_AS OR p.name LIKE 'Окно%' COLLATE SQL_Latin1_General_Cp1251_CI_AS ) 
GROUP by p.id_firm ORDER BY p.name ASC

但如果我使用它，我会得到错误：

Msg 8120，16级，状态1，第2行
列“Price.id\u Price”在选择列表中无效，因为它不包含在聚合函数或GROUP BY子句中

请告诉我更改此查询或进行其他查询的正确方法

构建所有您可以看到的表格

附言：对不起，不准确。按公司名称和产品名称搜索。如果搜索词包含在产品名称或公司名称中，并且有一些结果具有相同的id公司，则需要选择一个最合适的值，即搜索结果中的id公司应是唯一的。
使用而不是分组

对每个公司的行分别编号。当为
行编号（）对行进行排序时，使用
p.name，如'ö敪敪ö%'
条件将具有匹配产品的行放在其他行之前

下面是一个可能的示例：

;
WITH ranked AS (
  SELECT
    p.id_price as p_id_price, 
    p.id_service as p_id_service, 
    p.name as p_name, 
    p.name_original as p_name_original, 
    p.id_producer_country as p_id_producer_country, 
    p.id_firm as p_id_firm, 
    f.name as f_name, 
    f.address as f_address, 
    f.phone as f_phone, 
    city.name as city_name, 
    pc.name as pc_name,
    ROW_NUMBER() OVER (
      PARTITION BY p.id_firm
      ORDER BY
        CASE  -- this criterion puts matching products before non-matching ones
          WHEN p.name LIKE 'Окно%' COLLATE SQL_Latin1_General_Cp1251_CI_AS
          THEN 1 ELSE 2
        END,
        p.id_price  -- you may use any sorting criteria at this point,
                    -- just ensure it makes the results predictable
    ) AS rnk
  FROM Price p 
  left join Firm f 
    on f.id_service=p.id_service 
    AND f.id_city=p.id_city 
    AND f.id_firm=p.id_firm 
  left join City city 
    on city.id_city = p.id_city 
  left join Producer_country pc 
    on pc.id_producer_country = p.id_producer_country 
  WHERE p.id_city='73041' 
    AND p.include='1' 
    AND p.blocked='0' 
    AND f.blocked='0' 
    AND ( f.name LIKE 'Окно%' COLLATE SQL_Latin1_General_Cp1251_CI_AS
       OR p.name LIKE 'Окно%' COLLATE SQL_Latin1_General_Cp1251_CI_AS ) 
)
SELECT TOP 20
  p_id_price, 
  p_id_service, 
  p_name, 
  p_name_original, 
  p_id_producer_country, 
  p_id_firm, 
  f_name, 
  f_address, 
  f_phone, 
  city_name, 
  pc_name
FROM ranked
WHERE rnk = 1
-- the absence of ORDER BY makes your TOP 20 results indeterminate
;

基本上，这会对每个公司的行进行排序，然后只从所有公司中提取排名为
1
的行，最终使每个公司都有一行。
您可以尝试选择Distinct进行快速修复
表之间有哪些关系？请参考此示例[在此处输入链接说明][1][1]：好的，如果一家公司有多个人/服务/价格，您想要哪一个？您不能说“这不重要”，因为SQL Server需要知道。@HelloResh:在注释中，链接格式只支持
[text]（link）
模板。有关详细信息，请参阅。@LeoLoki您仍然需要具体说明。如果一家公司有两种产品，你想要哪种产品？