如何從兩個不同的表中獲取兩個不同的列值inturn一個值表依賴於其他表值

Question

以下查詢是我以前使用的查詢...但我想結合這兩個查詢以改進性能

select a, b, c 
    from table1 
where d LIKE 'xxx' 
    and f like 'yyyy' 
order by b desc; 

我正在執行上述查詢和讀取值。

對於從上面查詢b的每個值，再次在循環中執行下面的查詢。

select count(*) 
    from table2 where b=? AND js_email_id IN 
(
    select js_email_id 
    from js_initialsignup 
    where UCase(jsaccountstatus) LIKE UCase('live') 
    AND UCase(js_status) LIKEUCase('accepted') 
) 

如何組合兩個查詢並一次獲取計數和值？

Answer 1

select a,b,c, 
     (select count(*) 
from table2 where b=a.b AND js_email_id IN 
(
    select js_email_id 
    from js_initialsignup 
    where UCase(jsaccountstatus) LIKE UCase('live') 
    AND UCase(js_status) LIKEUCase('accepted') 
)) as cnt 

from table1 a 

Answer 2

試試這個：

SELECT t1.a, t1.b, t1.c, COUNT(t2.*) 
FROM table1 t1 
INNER JOIN table2 t2 ON t1.b = t2.b 
INNER JOIN js_initialsignup j ON t2.js_email_id = j.js_email_id 
WHERE t1.d LIKE 'xxx' 
    AND t1.f like 'yyyy' 
    AND UCase(j.jsaccountstatus) LIKE UCase('live') 
    AND UCase(j.js_status) LIKE UCase('accepted'))" 
GROUP BY t1.a, t1.b, t1.c 
ORDER BY by t1.b DESC;