mysql - 如何从两个不同的表中获取两个不同的列值反过来一个值表依赖于另一个表值

Question

以下查询是我以前使用的查询...但我想将这两个查询结合起来以提高性能

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

我正在执行上述查询并读取值。

对于上面查询中的每个 b 值，再次在循环中执行下面的查询。

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')
)

如何结合两个查询并一次获取计数和值？

Answer 1

试试这个：

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;

Answer 2

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