加入两个表，在三个列的行数列其中的语句

Question

我有一个表lot_bill_of_operations与行和表lot_bill_of_lots_serial_xref其中有序列号和时间戳列。这些表格通过主键bol_id相关联。

我想计算三个班次按行传递有多少个序列号，但每个子查询都有相同的结果。

下面是该查询：

select lot_bill_of_operations.wc_line_code, 

(select count(part_sn) from lot_bill_of_lots_serial_xref 
    where lot_bill_of_lots_serial_xref.time_stamp between '07-MAY-17 06:00:00' 
    and '07-MAY-17 14:00:00' 
    group by lot_bill_of_operations.wc_line_code)firstshift, 

(select count(part_sn) from lot_bill_of_lots_serial_xref 
    where lot_bill_of_lots_serial_xref.time_stamp between '07-MAY-17 14:00:00' 
    and '07-MAY-17 22:00:00' 
    group by lot_bill_of_operations.wc_line_code)secondshift, 

(select count(part_sn) from lot_bill_of_lots_serial_xref 
    where lot_bill_of_lots_serial_xref.time_stamp between '07-MAY-17 22:00:00' 
    and '08-MAY-17 06:00:00' 
    group by lot_bill_of_operations.wc_line_code)thirdshift 

FROM lot_bill_of_operations inner JOIN lot_bill_of_lots_serial_xref 
    ON lot_bill_of_operations.bol_id = lot_bill_of_lots_serial_xref.bol_id 
group by lot_bill_of_operations.wc_line_code 

这里是获取结果：

我在做什么错？

Answer 1

尝试以下操作：

select lot_bill_of_operations.wc_line_code 
, sum (case when time_stamp between '07-MAY-17 06:00:00' and '07-MAY-17 14:00:00' 
then 1 else 0 end) firstshift 
, sum (case when time_stamp between '07-MAY-17 14:00:00' and '07-MAY-17 22:00:00' 
then 1 else 0 end) secondshift 
, sum (case when time_stamp between '07-MAY-17 22:00:00' and '08-MAY-17 06:00:00' 
then 1 else 0 end) thirdshift 
FROM lot_bill_of_operations inner JOIN lot_bill_of_lots_serial_xref 
    ON lot_bill_of_operations.bol_id = lot_bill_of_lots_serial_xref.bol_id 
group by lot_bill_of_operations.wc_line_code 
; 

Answer 2

它看起来像你想有条件的计数，这可以用一个CASE表达式得到：

select lbo.wc_line_code, 
    count(case when lblsx.time_stamp between timestamp '2017-05-07 06:00:00' 
    and timestamp '2017-05-07 14:00:00' then lblsx.part_sn end) as firstshift, 
    count(case when lblsx.time_stamp between timestamp '2017-05-07 14:00:00' 
    and timestamp '2017-05-07 22:00:00' then lblsx.part_sn end) as secondshift, 
    count(case when lblsx.time_stamp between timestamp '2017-05-07 22:00:00' 
    and timestamp '2017-05-08 06:00:00' then lblsx.part_sn end) as thirdshift 
from lot_bill_of_operations lbo 
inner join lot_bill_of_lots_serial_xref lblsx 
on lbo.bol_id = lblsx.bol_id 
group by lbo.wc_line_code; 

我切换到时间戳文字，因为你是依靠您的NLS设置将字符串隐式转换为时间戳。 （或者可能是日期，从你所展示的内容来看并不清楚）。

但是，使用between意味着时段稍微重叠，所以你可能真的想：

select lbo.wc_line_code, 
    count(case when lblsx.time_stamp >= timestamp '2017-05-07 06:00:00' 
    and lblsx.time_stamp < timestamp '2017-05-07 14:00:00' then lblsx.part_sn end) as firstshift, 
    count(case when lblsx.time_stamp >= timestamp '2017-05-07 14:00:00' 
    and lblsx.time_stamp < timestamp '2017-05-07 22:00:00' then lblsx.part_sn end) as secondshift, 
    count(case when lblsx.time_stamp >= timestamp '2017-05-07 22:00:00' 
    and lblsx.time_stamp < timestamp '2017-05-08 06:00:00' then lblsx.part_sn end) as thirdshift 
from lot_bill_of_operations lbo 
inner join lot_bill_of_lots_serial_xref lblsx 
on lbo.bol_id = lblsx.bol_id 
group by lbo.wc_line_code; 

您可能还需要包括time_stamp范围内全面过滤，以减少数据的检验量：

... 
where lblsx.time_stamp >= timestamp '2017-05-07 06:00:00' 
and lblsx.time_stamp < timestamp '2017-05-08 06:00:00' 
group by lbo.wc_line_code; 

如果你在这一天的基础上，你可以使用日期算术，而不是固定值。

Answer 3

没有样本数据，很难理解你想要什么，但根据你的查询，我相信你需要像下面这样的东西。

• 还避免比较字符串的日期。使用日期转换函数 类似to_date/to_timestamp，同时比较精确的日期和 的非模糊结果。
• 使用between同时给出范围。

• 使用 别名为表名称更好的可读性。

  select o.wc_line_code 
      ,count(case when 
        x.time_stamp between to_date('07-MAY-17 06:00:00','DD-MON-YY HH24:MI:SS') 
            and to_date('07-MAY-17 14:00:00','DD-MON-YY HH24:MI:SS') 
        then 1) as firstshift 
  -- , similary for other shifts 
  
  FROM lot_bill_of_operations o 
      inner JOIN 
      lot_bill_of_lots_serial_xref x 
      ON o.bol_id = x.bol_id 
  group by o.wc_line_code;