Stored procedure: set output parameter from first row of select - sql-server

Question

I have a stored procedure in SQL Server 2014 that selects some rows from a table with pagination, along with total row count:
SELECT
[...], COUNT(*) OVER () AS RowCount
FROM
[...]
WHERE
[...]
ORDER BY
[...]
OFFSET ([..]) ROWS FETCH NEXT 3 ROWS ONLY
Output:
+----+------+----------+
| ID | Name | RowCount |
+----+------+----------+
| 1 | Bob | 55 |
| 123| John | 55 |
| 99 | Jack | 55 |
+----+------+----------+
I would like to return results with actual data only, passing RowCount in an output parameter.
+----+------+
| ID | Name |
+----+------+
| 1 | Bob |
| 123| John |
| 99 | Jack |
+----+------+
#OutRowCount = 55
I tried with a CTE, but CTE is available only within the first SELECT:
WITH CTE AS
(
SELECT [...], COUNT(*) OVER () AS RowCount
FROM [...]
WHERE [...]
ORDER BY [...]
OFFSET ([..]) ROWS FETCH NEXT 3 ROWS ONLY
)
SELECT
ID, Name
FROM
CTE
SET #OutRowCount = (SELECT TOP 1 RowCount FROM CTE) -- here CTE is no longer defined
How can I do this? I think I can use temp table but I wonder if in this case performance might be an issue.

Answer 1

The "total row count" you have in mind is a bit unclear. Typically when paging you also display to total number of (filtered) rows, e.g. "Showing 3 of 42 Blue Widgets". That doesn't involve Max.
A CTE can have multiple queries, e.g.:
with
AllRows as ( -- All of the filtered rows.
select ..., Count(*) over (...) as RowCount
from ...
where ... -- Filter criteria. ),
SinglePage as ( -- One page of filtered rows.
select ...
from AllRows
order by ... -- Order here to get the correct rows in the page.
offset (...) rows fetch next 3 rows only )
select SP.Id, SP.Name,
( select Count(42) from AllRows ) as TotalRowCount -- Constant over all rows.
from SinglePage
order by ...; -- Keep the rows in the desired order.
Re: SET #OutRowCount = (SELECT TOP 1 RowCount FROM CTE)
Note that TOP 1 without order by isn't guaranteed to pick the row you have in mind.

Answer 2

Thanks to #Larnu and #Stu, I solved this using a table variable, this way:
CREATE PROCEDURE MyProc
#OutRowCount INT OUTPUT
AS
BEGIN
DECLARE #TempTbl TABLE (
ID INT,
Name VARCHAR(MAX),
RowCount INT
)
INSERT INTO
#TempTbl
SELECT
ID,
Name,
COUNT(*) OVER() AS TotRighe
FROM
MyTable
WHERE
[...]
ORDER BY
Name
OFFSET ([...]) ROWS FETCH NEXT 3 ROWS ONLY
SELECT
ID,
Name
FROM
#TempTbl
SET #OutRowCount = ISNULL((SELECT TOP 1 RowCount FROM #TempTbl), 0)
END