Creating a derived table in SQL Server - sql-server

Question

I need some help summing two (or more) alias columns.
I know I need a derived table to do it, but so far I get lost with online tutorials and documentation as their examples are far too simple. they only have one table, two columns, etc.
What could be my best option here:
I need to calculate the sum of two alias columns: 'InFxO' and 'OnTxO' and my code is as follows:
ALTER PROC [dbo].[DIFOTIS]
#Mode as Varchar (5)
AS
Begin
Declare
#StartDate date,
#EndDate date
SET #StartDate=
CASE #Mode
WHEN 'MTD' THEN DATEADD(mm,DATEDIFF(mm,0,GETDATE()),0)
WHEN 'YTD' THEN DATEADD(yy,DATEDIFF(yy,0,GETDATE()),0)
WHEN 'QTD' THEN DATEADD(qq,DATEDIFF(qq,0,GETDATE()),0)
WHEN 'WTD' THEN DATEADD(wk,DATEDIFF(wk,0,GETDATE()),0)
END
Set #EndDate=
CASE #Mode
WHEN 'MTD' THEN DATEADD(mm,DATEDIFF(mm,0,GETDATE())+1,0)
WHEN 'YTD' THEN DATEADD(yy,DATEDIFF(yy,0,GETDATE())+1,0)
WHEN 'QTD' THEN DATEADD(qq,DATEDIFF(qq,0,GETDATE())+1,0)
WHEN 'WTD' THEN DATEADD(wk,DATEDIFF(wk,0,GETDATE())+1,0)
END
Select DATEPART(ISO_WEEK,d.DateOpn) AS 'Week#'
,Clients.CustCateg, Clients.ClntGroup
,d.DocumentCode as 'CORD_DocumentCode'
,CDSPDocs.DocumentCode AS 'DESP_DocumentCode'
,Count(CORDLines.Qnty) AS 'Cord_Lines'
,SUM(CORDLines.Qnty) AS 'CORD_Qty'
,Count(CDSPLines.Qnty) AS 'DESP_Lines'
,Sum(CDSPLines.Qnty) AS 'DESP_Qty'
,CDSPLines.Status, d.Status as d_status
,d.OpenDate, d.DateDue
,CDSPDocs.PostDate AS 'DESP_PostedDate'
,d.DocType, DATEDIFF(day, d.OpenDate, d.DateDue) AS 'Lead times'
--in-full
,CASE WHEN SUM(CORDLines.Qnty) = Sum(CDSPLines.Qnty) THEN '1' ELSE '0' END as InFxO
--On-Time by order according to Despatch SLAs
,CASE WHEN (Clients.ClntGroup IN ('Local Market','Local Market - Pharm','Web Sales - Local','Web Sales - Export', 'Mail Order','Mail Order - Export')) AND (Datediff(day, d.OpenDate, CDSPDocs.PostDate) - (Datediff(Week, d.OpenDate, CDSPDocs.PostDate)*2) <= 2) then '1'
WHEN (Clients.ClntGroup = 'Export Market') AND (Datediff(day, d.OpenDate, CDSPDocs.PostDate) - (Datediff(Week, d.OpenDate, CDSPDocs.PostDate)*2) <= 14) then '1'
WHEN (Clients.ClntGroup = 'Export Market') or Clients.CustCateg = 'UK Transfer' AND (d.DateDue >= CDSPDocs.PostDate) then '1'
ELSE '0'
END as OnTxO
From dbo.Documents AS d INNER JOIN
dbo.Clients ON d.ObjectID = dbo.Clients.ClntID AND Clients.ClientName <> 'Samples - Free / Give-aways' LEFT Outer JOIN
dbo.DocumentsLines AS CORDLines ON d.DocID = CORDLines.DocID AND CORDLines.TrnType = 'L'
LEFT OUTER JOIN
dbo.DocumentsLines AS CDSPLines ON CORDLines.TranID = CDSPLines.SourceID AND CDSPLines.TrnType = 'L' AND (CDSPLines.Status = 'Posted' OR CDSPLines.Status = 'Closed') LEFT OUTER JOIN
dbo.Documents AS CDSPDocs ON CDSPLines.DocID = CDSPDocs.DocID
WHERE (d.DocType IN ('CASW', 'CORD','MORD'))
AND (CORDLines.LneType NOT In ('Fght','MANF','Stor', 'PACK','EXPS'))
AND d.DateOpn >= #StartDate AND d.DateOpn < #EndDate
AND (CORDLines.LneType is not null)
AND (d.DateDue <= Convert(Date, GetDate(), 101))
Group by d.DateOpn
,d.DocumentCode
,Clients.CustCateg
,CDSPDocs.DocumentCode
,d.[Status]
,d.DocType
,d.OpenDate
,d.DateReq
,CDSPDocs.PostDate
,CDSPLines.[Status]
,Clients.ClntGroup
,d.DocumentName
,d.DateDue
,d.DateOpn
ORDER BY d.DateOpn, 'Week#'
END
GO
All help is appreciated.
Thanks
H

Answer 1

Below is an example that wraps the original query in a derived table so that you don't need to repeat the CASE expressions for the SUM. You could similarly wrap the query in a common table expression to achieve the same result.
I suggest you use single-quotes only to enclose string literals and enclose identifiers (column names, aliases, and object names) with either square brackets or double quotes as described in the SQL Server Books Online reference (http://msdn.microsoft.com/en-us/library/ms175874.aspx). Identifiers need be enclosed only when they don't conform to identifier naming rules or are a reserved keyword.
ALTER PROC dbo.DIFOTIS #Mode AS varchar(5)
AS
BEGIN
DECLARE #StartDate date
, #EndDate date;
SET #StartDate = CASE #Mode
WHEN 'MTD'
THEN DATEADD(mm, DATEDIFF(mm, 0, GETDATE()), 0)
WHEN 'YTD'
THEN DATEADD(yy, DATEDIFF(yy, 0, GETDATE()), 0)
WHEN 'QTD'
THEN DATEADD(qq, DATEDIFF(qq, 0, GETDATE()), 0)
WHEN 'WTD'
THEN DATEADD(wk, DATEDIFF(wk, 0, GETDATE()), 0)
END;
SET #EndDate = CASE #Mode
WHEN 'MTD'
THEN DATEADD(mm, DATEDIFF(mm, 0, GETDATE()) + 1, 0)
WHEN 'YTD'
THEN DATEADD(yy, DATEDIFF(yy, 0, GETDATE()) + 1, 0)
WHEN 'QTD'
THEN DATEADD(qq, DATEDIFF(qq, 0, GETDATE()) + 1, 0)
WHEN 'WTD'
THEN DATEADD(wk, DATEDIFF(wk, 0, GETDATE()) + 1, 0)
END;
SELECT Week#
, CustCateg
, ClntGroup
, CORD_DocumentCode
, DESP_DocumentCode
, Cord_Lines
, CORD_Qty
, DESP_Lines
, DESP_Qty
, Status
, d_status
, OpenDate
, DateDue
, DESP_PostedDate
, DocType
, [Lead times]
, InFxO
, OnTxO
, InFxO + OnTxO AS InFullAndOneTime
FROM (
SELECT DATEPART(ISO_WEEK, d.DateOpn) AS Week#
, Clients.CustCateg
, Clients.ClntGroup
, d.DocumentCode AS CORD_DocumentCode
, CDSPDocs.DocumentCode AS DESP_DocumentCode
, COUNT(CORDLines.Qnty) AS Cord_Lines
, SUM(CORDLines.Qnty) AS CORD_Qty
, COUNT(CDSPLines.Qnty) AS DESP_Lines
, SUM(CDSPLines.Qnty) AS DESP_Qty
, CDSPLines.Status
, d.Status AS d_status
, d.OpenDate
, d.DateDue
, CDSPDocs.PostDate AS DESP_PostedDate
, d.DocType
, DATEDIFF(DAY, d.OpenDate, d.DateDue) AS [Lead times]
--in-full
, CASE WHEN SUM(CORDLines.Qnty) = SUM(CDSPLines.Qnty) THEN 1
ELSE 0
END AS InFxO
--On-Time by order according to Despatch SLAs
, CASE WHEN ( Clients.ClntGroup IN ( 'Local Market',
'Local Market - Pharm',
'Web Sales - Local',
'Web Sales - Export',
'Mail Order',
'Mail Order - Export' ) )
AND ( DATEDIFF(DAY, d.OpenDate, CDSPDocs.PostDate)
- ( DATEDIFF(WEEK, d.OpenDate,
CDSPDocs.PostDate) * 2 ) <= 2 )
THEN 1
WHEN ( Clients.ClntGroup = 'Export Market' )
AND ( DATEDIFF(DAY, d.OpenDate, CDSPDocs.PostDate)
- ( DATEDIFF(WEEK, d.OpenDate,
CDSPDocs.PostDate) * 2 ) <= 14 )
THEN 1
WHEN ( Clients.ClntGroup = 'Export Market' )
OR Clients.CustCateg = 'UK Transfer'
AND ( d.DateDue >= CDSPDocs.PostDate ) THEN '1'
ELSE 0
END AS OnTxO
FROM dbo.Documents AS d
INNER JOIN dbo.Clients ON d.ObjectID = dbo.Clients.ClntID
AND Clients.ClientName <> 'Samples - Free / Give-aways'
LEFT OUTER JOIN dbo.DocumentsLines AS CORDLines ON d.DocID = CORDLines.DocID
AND CORDLines.TrnType = 'L'
LEFT OUTER JOIN dbo.DocumentsLines AS CDSPLines ON CORDLines.TranID = CDSPLines.SourceID
AND CDSPLines.TrnType = 'L'
AND ( CDSPLines.Status = 'Posted'
OR CDSPLines.Status = 'Closed'
)
LEFT OUTER JOIN dbo.Documents AS CDSPDocs ON CDSPLines.DocID = CDSPDocs.DocID
WHERE ( d.DocType IN ( 'CASW', 'CORD', 'MORD' ) )
AND ( CORDLines.LneType NOT IN ( 'Fght', 'MANF', 'Stor',
'PACK', 'EXPS' ) )
AND d.DateOpn >= #StartDate
AND d.DateOpn < #EndDate
AND ( CORDLines.LneType IS NOT NULL )
AND ( d.DateDue <= CONVERT(date, GETDATE(), 101) )
GROUP BY d.DateOpn
, d.DocumentCode
, Clients.CustCateg
, CDSPDocs.DocumentCode
, d.Status
, d.DocType
, d.OpenDate
, d.DateReq
, CDSPDocs.PostDate
, CDSPLines.Status
, Clients.ClntGroup
, d.DocumentName
, d.DateDue
, d.DateOpn
) AS derived_table
ORDER BY d.DateOpn
, Week#;
END;
GO