Finding missing sequence number in SQL 2008 table - sql-server-2008

Question

I have a table that return the below by this query:
SELECT *
FROM [PROC_MN]
where PO_NO='GV17885' AND DOC_NO='622843'
ID PO_NO DOC_NO PROCESS_SEQ PROCESS_NAME STATUS TIME
756 GV17885 622843 2 R.M.Requisition Start 23-04-18 15:29
788 GV17885 622843 2 R.M.Requisition Finish 23-04-18 15:50
289 GV17885 622843 1 CTP Start 23-04-18 8:57
426 GV17885 622843 1 CTP Finish 23-04-18 10:09
901 GV17885 622843 3 Material Cut Start 23-04-18 17:23
903 GV17885 622843 3 Material Cut Finish 23-04-18 17:26
1669 GV17885 622843 4 Print Start 24-04-18 13:59
1712 GV17885 622843 4 Print Finish 24-04-18 14:44
3421 GV17885 622843 5 Q.C Start 27-04-18 8:04
3492 GV17885 622843 5 Q.C Finish 27-04-18 8:42
3630 GV17885 622843 7 RFID Start 27-04-18 9:36
3632 GV17885 622843 7 RFID Finish 27-04-18 9:38
4264 GV17885 622843 8 Q.C Start 27-04-18 14:58
4288 GV17885 622843 8 Q.C Finish 27-04-18 15:16
4729 GV17885 622843 9 Encode Start 28-04-18 8:48
4734 GV17885 622843 9 Encode Finish 28-04-18 8:49
4698 GV17885 622843 9 Encode Start 28-04-18 8:24
4722 GV17885 622843 9 Encode Finish 28-04-18 8:47
5016 GV17885 622843 10 Q.C Start 28-04-18 13:38
5073 GV17885 622843 10 Q.C Finish 28-04-18 14:11
I want to find the missing PROCESS_SEQ row, with the above result we found that the missing PROCESS_SEQ is number 6 . I use the following query but it return nothing/. Please help!
SET NOCOUNT ON;
DECLARE #Min BIGINT
DECLARE #Max BIGINT
DECLARE #i BIGINT
IF OBJECT_ID('tempdb..#TempTable') IS NOT NULL
BEGIN
DROP TABLE #TempTable
END
CREATE TABLE #TempTable
(
TempOrderNumber BIGINT
)
SELECT #Min = ( SELECT MIN([PROCESS_SEQ])
FROM [PROC_MN] WITH ( NOLOCK )
WHERE PO_NO='GV17885' AND [DOC_NO]='622843')
SELECT #Max = ( SELECT MAX([PROCESS_SEQ])
FROM [PROC_MN] WITH ( NOLOCK )
WHERE PO_NO='GV17885' AND [DOC_NO]='622843')
SELECT #i = #Min
WHILE #i <= #Max
BEGIN
INSERT INTO #TempTable
SELECT #i
SELECT #i = #i + 1
END
SELECT TempOrderNumber
FROM #TempTable
LEFT JOIN [PROC_MN] o WITH ( NOLOCK ) ON tempordernumber = o.[PROCESS_SEQ]
WHERE o.[PROCESS_SEQ] IS NULL

Answer 1

You may try the following query:
WITH
[MISSING_RANGES] AS
(
SELECT
[MISSING_RANGE_NO] = ROW_NUMBER() OVER (ORDER BY P.[PO_NO], P.[DOC_NO], P.[PROCESS_SEQ]),
P.[PO_NO],
P.[DOC_NO],
[FIRST_MISSING] = P.[PROCESS_SEQ] + 1,
[LAST_MISSING] = N.[PROCESS_SEQ] - 1
FROM
[PROC_MN] AS P
OUTER APPLY (SELECT [PROCESS_SEQ] = MIN([PROCESS_SEQ])
FROM [PROC_MN]
WHERE
[PO_NO] = P.[PO_NO] AND
[DOC_NO] = P.[DOC_NO] AND
[PROCESS_SEQ] > P.[PROCESS_SEQ]) AS N
WHERE
N.[PROCESS_SEQ] > P.[PROCESS_SEQ] + 1
),
[MISSING_SEQUENCES] AS
(
SELECT
[MISSING_RANGE_NO],
[MISSING_PROCESS_SEQ] = [FIRST_MISSING]
FROM
[MISSING_RANGES]
UNION ALL
SELECT
R.[MISSING_RANGE_NO],
S.[MISSING_PROCESS_SEQ] + 1
FROM
[MISSING_RANGES] AS R
INNER JOIN [MISSING_SEQUENCES] AS S ON S.[MISSING_RANGE_NO] = R.[MISSING_RANGE_NO]
WHERE
S.[MISSING_PROCESS_SEQ] < R.[LAST_MISSING]
)
SELECT DISTINCT
R.[PO_NO],
R.[DOC_NO],
S.[MISSING_PROCESS_SEQ]
FROM
[MISSING_RANGES] AS R
INNER JOIN [MISSING_SEQUENCES] AS S ON S.[MISSING_RANGE_NO] = R.[MISSING_RANGE_NO]
--WHERE
-- R.[PO_NO] = ? AND
-- R.[DOC_NO] = ?
ORDER BY
R.[PO_NO],
R.[DOC_NO],
S.[MISSING_PROCESS_SEQ]
OPTION (MAXRECURSION 10000);
(I put the WHERE clause to filter for specific [PO_NO] AND [DOC_NO] values in comment for testing purposes.)
Edit (in response to the additional updated post):
This is my personal version of your SQL-script. Just like yours, it generates a temp table containing a sequence (from minimum to maximum) and selects all values where the record from the data table cannot be joined:
DECLARE #PO_NO VARCHAR(10) = 'GV17885';
DECLARE #DOC_NO VARCHAR(10) = '622843';
DECLARE #TempTable TABLE
(
[TempOrderNumber] BIGINT PRIMARY KEY
);
DECLARE #Min BIGINT;
DECLARE #Max BIGINT;
SELECT
#Min = MIN([PROCESS_SEQ]),
#Max = MAX([PROCESS_SEQ])
FROM
[PROC_MN] WITH (NOLOCK)
WHERE
[PO_NO] = #PO_NO AND
[DOC_NO] = #DOC_NO;
DECLARE #i BIGINT = #Min;
WHILE (#i <= #Max) BEGIN
INSERT INTO #TempTable ([TempOrderNumber])
SELECT #i;
SET #i += 1;
END;
SELECT
[TempOrderNumber]
FROM
#TempTable
LEFT JOIN [PROC_MN] AS O WITH (NOLOCK) ON
[TempOrderNumber] = O.[PROCESS_SEQ]
AND O.[PO_NO] = #PO_NO
AND O.[DOC_NO] = #DOC_NO
WHERE
O.[PROCESS_SEQ] IS NULL;
This should work correctly too. But I personally prefer my original query, since it is based on set operations instead of loops.