子查询总和

Question

我的查询是

select count(*) as cnt,
       EXTRACT(day FROM current_date - min(txdate))::int as days,

       sum (Select opening from acledgerbal l 
              where acname='Arv' 
              union all 
              Select sum(v2.debit-v2.credit) as opening from acvoucher2 v2 where
              txdate<='05/03/2014') as opening

from acduebills acb,acledger l 

where (acb.opening+acb.debit-acb.credit) > 0 
   and acb.unitname='Sales' 
   and l.acname='Arv' 
   and l.acno=acb.acno

此处显示more than one row returned by a subquery used as an expression Error。 如何将sum用于子查询。

我正在使用PostgreSQL 9.1

编辑：

我想获取acduebills表中的行数，即（acb.opening + acb.debit-acb.credit）> 0和acb.unitname ='Sales'。 之后，我想获得在相同条件下的最小日期的天数差异。 之后，我要开始打开，它来自两个表： acledgerbal和acvoucher2 。 acvoucher是通过txdate条件检查的。

如何在单个查询中获取那些详细信息？ 如何在多个架构中获取相同的详细信息？

Answer 1

问题在下面的语句中：

   sum (  Select opening from acledgerbal l 
          where acname='Arv' 
          union all 
          Select sum(v2.debit-v2.credit) as opening from acvoucher2 v2,
          txdate<='05/03/2014' ) 

您使用UNION，因此此子查询至少返回2行。 因此，您将收到一个错误，即子查询不能返回多于一行：“子查询作为表达式返回的多于一行”

尝试将其更改为：

   (Select SUM(opening) from acledgerbal l WHERE acname='Arv')
   +  
   (Select SUM(v2.debit-v2.credit) as opening from acvoucher2 v2 
                                           WHERE txdate<='05/03/2014')

Answer 2

像这样：

SELECT count(*) AS cnt
     , current_date - min(txdate)::date AS days   -- subtract dates directly

     , (SELECT round(sum(opening)::numeric, 2)
        FROM  (
           SELECT opening
           FROM   acledgerbal
           WHERE  acname = 'Arv' 

           UNION ALL
           SELECT debit - credit
           FROM   acvoucher2
           WHERE  txdate <= '2014-05-03'
           ) sub
       ) AS opening
FROM   acduebills b
JOIN   acledger   l USING (acno)
WHERE ((b.opening + b.debit) - b.credit) > 0 
AND    b.unitname ='Sales' 
AND    l.acname = 'Arv';

round()到小数位仅适用于numeric类型，因此我将总和转换。