GROUP BY的COUNT（*）

Question

我有一个返回644行的查询，按几列分组。我需要计算这些行，644。

这是查询：

SELECT DISTINCT ho.ID,ho.honame,ho.ho_status,SUM(Properties.Value) as [sales value], COUNT(Properties.record_id) as [property count]
FROM HeadOffice ho INNER JOIN Properties ON Properties.head_office_code = ho.id
WHERE Somecondition
GROUP BY ho.ID,ho.honame,ho_status ORDER BY ho_status

尽管尝试COUNT(*)，将其包装在另一个查询中并删除GROUP BY，我仍然无法获得'644'。我最接近的是644行，都包含'1'。这可能吗？

Answer 1

这样做的简单方法就是：

SELECT count(1) as NumRows from
(SELECT DISTINCT ho.ID,ho.honame,ho.ho_status,SUM(Properties.Value) as [sales value], COUNT(Properties.record_id) as [property count]
FROM HeadOffice ho INNER JOIN Properties ON clients.head_office_code = ho.id
WHERE Somecondition
GROUP BY ho.ID,ho.honame,ho_status ORDER BY ho_status) x

如果您想要计数加上列数，请使用over：

SELECT 
    count(1) over () as NumRows,
    x.ID,
    x.ho_status,
    x.[sales value],
    x.[property count]
from
(SELECT DISTINCT ho.ID,ho.honame,ho.ho_status,SUM(Properties.Value) as [sales value], COUNT(Properties.record_id) as [property count]
FROM HeadOffice ho INNER JOIN Properties ON clients.head_office_code = ho.id
WHERE Somecondition
GROUP BY ho.ID,ho.honame,ho_status ORDER BY ho_status) x

Answer 2

您将在列表中再获得1行，其中包含除属性计数和属性值之外的所有内容的空值。该记录将具有计数和所有属性值的总和。

SELECT DISTINCT ho.ID,ho.honame,ho.ho_status, 
SUM(Properties.Value) as [sales value], 
COUNT(Properties.record_id) as [property count]
FROM HeadOffice ho 
INNER JOIN Properties 
  ON clients.head_office_code = ho.id
WHERE Somecondition
GROUP BY Grouping sets((ho.ID,ho.honame,ho_status),()) 
ORDER BY ho_status

Answer 3

这应该有效

SELECT COUNT(ID) 
FROM (
SELECT DISTINCT ho.ID,ho.honame,ho.ho_status,
       SUM(Properties.Value) as [sales value], 
       COUNT(Properties.record_id) as [property count]
FROM HeadOffice ho 
     INNER JOIN Properties ON clients.head_office_code = ho.id
WHERE Somecondition
GROUP BY ho.ID, ho.honame, ho_status ) t