更改子查詢

Question

我得到了這樣的查詢，其作爲它的工作應該工作，但我不知道如何在一個查詢使其

SELECT 
(
Select count(exists) 
from country c 
    join special s ON c.id_special = s.id 
    join raports rap ON c.id = rap.id_raport 
where c.id_document = 7 and exists = 1 
and rap.id_data = 201501 and is_id = 1 
) as number_of_ID_in_table_exists, 
(
Select count(sps) 
from country c 
join special s ON c.id_special = s.id 
join raports rap ON c.id = rap.id_raport 
where c.id_document = 7 and sps = 1 
and rap.id_data = 201501 and is_id2 = 1 
) as number_of_ID2_in_table_exists; 

Answer 1

使用case表達式進行條件計數：

Select count(case when exists = 1 and is_id = 1 then 1 end) as number_of_ID_in_table_exists, 
     count(case when sps = 1 and is_id2 = 1 then 1 end) as number_of_ID2_in_table_exists 
from country c 
    join special s ON c.id_special = s.id 
    join raports rap ON c.id = rap.id_raport 
where rap.id_data = 201501 and c.id_document = 7 

Answer 2

SELECT SUM(CASE WHEN is_id = 1 THEN 1 END) number_of_ID_in_table_exists 
     SUM(CASE WHEN is_id2 = 1 THEN 1 END) number_of_ID2_in_table_exists 
FROM country c 
JOIN special s ON c.id_special = s.id 
JOIN raports rap ON c.id = rap.id_raport 
WHERE c.id_document = 7 AND rap.id_data = 201501 AND [exists]= 1