Question

我为我的客户端所需的查询编写了这段代码。结果给出了我们所需要的，但是我得到了一些非常长的响应时间。查询的第一部分比第二部分要长，当查询本身并没有太大的不同。基本上它们是两个不同的查询，我使用UNION ALL合并为一个。

任何反馈都可以很好地简化这一点。感谢

Select * from
(

Select b.Storage_Loc_Nbr as locNbr, b.CurrentLoadCount,b.MMM_Id_Nbr,
(SELECT count(Load_ID) as LoadCount 
    FROM t_load c
    WHERE b.MMM_Id_Nbr=c.MMM_Id_Nbr
    and
    QC_Status_Code like 'R%' and mmm_Facility_Code ='MC' and     Active_Status_Ind='A'
    and
    b.Storage_Loc_Nbr <> c.Storage_Loc_Nbr)as OtherLocCount

    FROM
(

SELECT * FROM

(

    SELECT t_load.Storage_Loc_Nbr, 
    Count(t_Load.Load_Id) AS CurrentLoadCount,
    t_load.MMM_Id_Nbr,
    t_Storage_Location.Storage_Loc_Type_Code

    FROM t_Load LEFT JOIN t_Storage_Location ON t_Load.Storage_Loc_Nbr = t_Storage_Location.Storage_Loc_Nbr
    WHERE (

    ((t_load.MMM_Id_Nbr) between '702004%' and '702011%')
    AND ((t_Load.Active_Status_Ind)='A')
    AND ((t_Load.QC_Status_Code) Like 'R%') 
    AND ((t_Load.MMM_Facility_Code)='MC')
    AND  ((t_Storage_Location.Storage_Loc_Type_Code)='CD')
)

    GROUP BY t_load.MMM_Id_Nbr,
    t_load.Storage_Loc_Nbr,
    t_Storage_Location.Storage_Loc_Type_Code

 HAVING
    Count(t_Load.Load_Id)<=1




    )
    as a

)  
as b


)
as c
Group By
locNbr,CurrentLoadCount, MMM_Id_Nbr, OtherLocCount
having OtherLocCount>0

UNION ALL

Select * from
(

Select b.Storage_Loc_Nbr as locNbr, b.CurrentLoadCount,b.MMM_Id_Nbr,
(SELECT count(Load_ID) as LoadCount 
    FROM t_load c
    WHERE b.MMM_Id_Nbr=c.MMM_Id_Nbr
    and
    QC_Status_Code like 'R%' and mmm_Facility_Code ='MC' and Active_Status_Ind='A'
    and
    b.Storage_Loc_Nbr <> c.Storage_Loc_Nbr)as OtherLocCount

 FROM
(

SELECT * FROM

(

    SELECT t_load.Storage_Loc_Nbr, 
    Count(t_Load.Load_Id) AS CurrentLoadCount,
    t_load.MMM_Id_Nbr,
    t_Storage_Location.Storage_Loc_Type_Code

    FROM t_Load LEFT JOIN t_Storage_Location ON t_Load.Storage_Loc_Nbr = t_Storage_Location.Storage_Loc_Nbr
    WHERE (

    ((t_load.MMM_Id_Nbr) between '702004%' and '702011%')
    AND ((t_Load.Active_Status_Ind)='A')
    AND ((t_Load.QC_Status_Code) Like 'R%') 
    AND ((t_Load.MMM_Facility_Code)='MC')
    AND  ((t_Storage_Location.Storage_Loc_Type_Code)<>'CD') AND
    ((t_load.Storage_Loc_Nbr)<>'clc' AND (t_load.Storage_Loc_Nbr)<>'WHLEAD')    AND
(
((t_load.Storage_Loc_Nbr) Like '%A') 
OR((t_load.Storage_Loc_Nbr) Like '%B')
OR ((t_load.Storage_Loc_Nbr) Like '%C') 
OR ((t_load.Storage_Loc_Nbr) Like '%D') 
OR ((t_load.Storage_Loc_Nbr) Like '%E'))
)

    GROUP BY t_load.MMM_Id_Nbr,
    t_load.Storage_Loc_Nbr,
    t_Storage_Location.Storage_Loc_Type_Code



    HAVING
    Count(t_Load.Load_Id)<=1



    )
    as a

)  
as b


)
as c
Group By
locNbr,CurrentLoadCount, MMM_Id_Nbr, OtherLocCount
having OtherLocCount>0
Order by
LocNbr

Answer 1

我只看了工会的第一部分

http://sqlfiddle.com/#!3/72b6d/9/0与原始查询非常相似，只有一些简化，优化器可能会自行完成。

http://sqlfiddle.com/#!3/72b6d/11/0与我编写的测试数据产生相同的结果。随意扩展这个更具代表性的东西。它使用CTE（下面复制）

-- CTE Version
With T As (
Select
  l.Storage_Loc_Nbr,
  l.MMM_Id_Nbr,
  Count(Load_ID) As LoadCount
From 
  t_load l
Where
  l.QC_Status_Code like 'R%' And
  l.mmm_Facility_Code ='MC' And
  l.Active_Status_Ind='A' And
  l.MMM_Id_Nbr between '702004%' and '702011%'
Group By
  l.Storage_Loc_Nbr,
  l.MMM_Id_Nbr
)

Select
  t1.Storage_Loc_Nbr LocNbr,
  t1.LoadCount CurrentLoadCount,
  t1.MMM_Id_Nbr,
  t2.TotalCount - t1.LoadCount OtherLocCount
From
  T t1
    Inner Join (
      Select
        MMM_Id_Nbr,
        Sum(LoadCount) TotalCount
      From
        T  
      Group By
        MMM_Id_Nbr
    ) t2
    On t1.MMM_Id_Nbr = t2.MMM_Id_Nbr
    Left Outer Join
  t_Storage_Location sl
    On t1.Storage_Loc_Nbr = sl.Storage_Loc_Nbr
Where
  sl.Storage_Loc_Type_Code = 'CD' and
  t1.LoadCount <= 1 And
  t2.TotalCount - t1.LoadCount > 0

http://sqlfiddle.com/#!3/72b6d/6/0是另一个使用窗口函数以及无偿CTE的版本：

-- Window Function Version
With T As (
Select
  l.MMM_Id_Nbr,
  l.Storage_Loc_Nbr,
  Count(Load_ID) Over (Partition By MMM_ID_Nbr, Storage_Loc_Nbr) As LoadCount,
  Count(Load_ID) Over (Partition By MMM_ID_Nbr) As TotalCount
From 
  t_load l
Where
  QC_Status_Code like 'R%' And
  mmm_Facility_Code ='MC' And
  Active_Status_Ind='A' And
  l.MMM_Id_Nbr between '702004%' and '702011%'
)

Select
  t1.Storage_Loc_Nbr LocNbr,
  t1.LoadCount CurrentLoadCount,
  t1.MMM_Id_Nbr,
  t1.TotalCount - t1.LoadCount OtherLocCount
From
  T t1
    Left Outer Join
  t_Storage_Location sl
    On t1.Storage_Loc_Nbr = sl.Storage_Loc_Nbr
Where
  sl.Storage_Loc_Type_Code = 'CD' and
  t1.LoadCount <= 1 And
  t1.TotalCount - t1.LoadCount > 0

Answer 2

(SELECT count(Load_ID) as LoadCount  
    FROM t_load c 
    WHERE b.MMM_Id_Nbr=c.MMM_Id_Nbr 
    and 
    QC_Status_Code like 'R%' and mmm_Facility_Code ='MC' and     Active_Status_Ind='A' 
    and 
    b.Storage_Loc_Nbr <> c.Storage_Loc_Nbr)as OtherLocCount

这是一个相关的子查询。这意味着它逐行运行。这是一种您应该避免使用的编程技术。把它变成派生表。

如何简化/优化此union语句

2 个答案: