Count of rows returned by 2 out of 3 SELECTs combined with UNION

Question

I have a hard time titling this post.

How can we accomplish the following?

SELECT 'Body' AS LineType, ItemName, Quantity FROM TableX
UNION ALL
SELECT 'Body' AS LineType, ItemName, Quantity FROM TableY
UNION ALL
SELECT 'Trailer' AS LineType, null As ItemName, <count of the above two SELECTs> 

The result should look like this:

LineType     ItemName     Qty
Body         Nut          19
Body         Bolt         25
Trailer      NULL         2

Please help; Thank you SOF community.

Answer 1

try a CTE:

;WITH FirstQ AS 
(
    SELECT 'Body' AS LineType, ItemName, Quantity FROM TableX
), SecondQ AS 
(
    SELECT 'Body' AS LineType, ItemName, Quantity FROM TableY
)
SELECT * FROM FirstQ
UNION ALL SELECT * FROM SecondQ
UNION ALL
SELECT 'Trailer' AS LineType, null As ItemName, ((SELECT COUNT(*) FROM FirstQ) +(SELECT COUNT(*) FROM SecondQ)) AS Quantity

Working sample code:

declare @TableX table (ItemName varchar(5), Quantity int)
INSERT @TableX VALUES ('aa',10)
INSERT @TableX VALUES ('bb',20)

declare @TableY table (ItemName varchar(5), Quantity int)
INSERT @TableX VALUES ('cc',30)

;WITH FirstQ AS 
(
    SELECT 'Body' AS LineType, ItemName, Quantity FROM @TableX
), SecondQ AS 
(
    SELECT 'Body' AS LineType, ItemName, Quantity FROM @TableY
)
SELECT * FROM FirstQ
UNION ALL SELECT * FROM SecondQ
UNION ALL
SELECT 'Trailer' AS LineType, null As ItemName, ((SELECT COUNT(*) FROM FirstQ) +(SELECT COUNT(*) FROM SecondQ)) AS Quantity

OUTPUT:

LineType ItemName Quantity
-------- -------- -----------
Body     aa       10
Body     bb       20
Body     cc       30
Trailer  NULL     3

(4 row(s) affected)

Answer 2

declare @TableX table (ItemName varchar(10),Quantity int)
declare @TableY table (ItemName varchar(10),Quantity int)

insert @tableX VALUES('door',0)
insert @tableX VALUES('window',10)
insert @tableX VALUES('wheel',5)
insert @tableX VALUES('brake',7)
insert @tableX VALUES('handle',3)
insert @tableX VALUES('lamp',207)

insert @tableY VALUES('Ydoor',0)
insert @tableY VALUES('Ywindow',10)
insert @tableY VALUES('Ywheel',5)
insert @tableY VALUES('Ybrake',7)
insert @tableY VALUES('Yhandle',3)
insert @tableY VALUES('Ylamp',207)

SELECT 'Body' as LineType, ItemName, Sum(Quantity) qty, Count(*) [count] FROM
(
SELECT ItemName, Quantity FROM @TableX
UNION
SELECT ItemName, Quantity FROM @TableY
) u

GROUP BY ItemName WITH ROLLUP