Query, subquery and using as variables from subquery - sql

Question

Is it not possible to use the "as [item] and then use the item variable in the query.
For example:
select c.category as [category],c.orderby as [CatOrder], m.masterno, m.master
,-- select OUT (select count(*) from rentalitem ri with (nolock),
rentalitemstatus ris with (nolock),
rentalstatus rs with (nolock)
where ri.rentalitemid = ris.rentalitemid
and ris.rentalstatusid = rs.rentalstatusid
and ri.masterid = m.masterid
and rs.statustype in ('OUT', 'INTRANSIT', 'ONTRUCK')) as [qtyout]
,-- select OWNED owned=
(select top 1 mwq.qty
from masterwhqty mwq
where mwq.masterid = m.masterid)
, -([owned]-[qtyout]) as [Variance]
from master m
inner join category c on c.categoryid=m.categoryid and c.categoryid=#category
inner join inventorydepartment d on c.inventorydepartment=#department
I cannot seem to use qtyout or owned when calculating variance. How can I do that?

Answer 1

You can also use a table variable and then reference that table variable like you are trying to do above....here's an example from MSDN
USE AdventureWorks2012;
GO
DECLARE #MyTableVar table(
EmpID int NOT NULL,
OldVacationHours int,
NewVacationHours int,
ModifiedDate datetime);
UPDATE TOP (10) HumanResources.Employee
SET VacationHours = VacationHours * 1.25,
ModifiedDate = GETDATE()
OUTPUT inserted.BusinessEntityID,
deleted.VacationHours,
inserted.VacationHours,
inserted.ModifiedDate
INTO #MyTableVar;
--Display the result set of the table variable.
SELECT EmpID, OldVacationHours, NewVacationHours, ModifiedDate
FROM #MyTableVar;
GO
--Display the result set of the table.
SELECT TOP (10) BusinessEntityID, VacationHours, ModifiedDate
FROM HumanResources.Employee;
GO

Answer 2

need to move your calculated fields into a subquery, and then use them by their alias in the outer query.
select subquery.*, -([owned]-[qtyout]) as [Variance]
from
(
select c.category as [category],c.orderby as [CatOrder], m.masterno, m.master
,-- select OUT (select count(*) from rentalitem ri with (nolock),
rentalitemstatus ris with (nolock),
rentalstatus rs with (nolock)
where ri.rentalitemid = ris.rentalitemid
and ris.rentalstatusid = rs.rentalstatusid
and ri.masterid = m.masterid
and rs.statustype in ('OUT', 'INTRANSIT', 'ONTRUCK')) as [qtyout]
,-- select OWNED owned=
(select top 1 mwq.qty
from masterwhqty mwq
where mwq.masterid = m.masterid) as [owned]
from master m
inner join category c on c.categoryid=m.categoryid and c.categoryid=#category
inner join inventorydepartment d on c.inventorydepartment=#department
) as subquery

Answer 3

YOu need to use a subquery:
select t.*,
([owned]-[qtyout]) as [Variance]
from (<something like your query here
) t
You query, even without the comments, doesn't quite make sense (select OUT (select . . . for isntance). But, the answer to your question is to define the base variables in a subquery or CTE and then subsequently use them.
And, you are calling the difference "variance". Just so you know, you are redefining the statistical meaning of the term (http://en.wikipedia.org/wiki/Variance), which is based on the squares of the differences.