Find missing integers in a list of Values - sql-server

Question

Currently, I have 12 rows with column Named 'Value'. The sample like this (just sample data, real data will be more):
Value
1
2
3
4
6
7
8
9
10
11
12
14
What I want is select them to get result like this:
Result Result_Miss
1-4, 6-12, 14 5, 13
I want to avoid using a cursor to work row-by-row.

Answer 1

Dynamic, set-based approach using CTEs to hunt down the missing values, and write out the ranges available based on those missing values.
--(I can't seem to get SqlFiddle to work with CTE's or I'd post one up here)--
Reworked to be more dynamic for number of records:
This works provided you always have '1' in your set of value
CREATE TABLE #OneTen
(
Value INT NOT NULL
);
INSERT INTO #OneTen
VALUES (1), (2), (3), (4), (6), (8), (9), (10), (11), (12), (14);
WITH ExpectedActual AS
(
SELECT ot.Value AS Actual, ROW_NUMBER() OVER (ORDER BY Value) AS Expected
FROM #OneTen AS ot
)
, DegreesOff AS
(
SELECT ea.Expected, ea.Actual, (ea.Actual - ea.Expected) AS Change
FROM ExpectedActual AS ea
)
, Missing AS
(
SELECT CASE
WHEN MIN(do.Expected) = 1 THEN 0
ELSE MIN(do.Expected) + do.Change - 1
END AS Missing
, ROW_NUMBER() OVER (ORDER BY MIN(do.Expected)) AS RowNumber
FROM DegreesOff AS do
GROUP BY do.Change
UNION ALL
SELECT MAX(do.Actual + 1), MAX(do.Change + 2) --Adding Last Value 1 higher than Actual so the code below that takes mNext.Missing - 1 brings it down to the proper value:
--Change + 2 to account for 0 plus being 1 higher
FROM DegreesOff AS do
)
SELECT STUFF((
SELECT ', ' + CASE
WHEN m.Missing + 1 = mNext.Missing - 1 THEN CAST(m.Missing + 1 AS NVARCHAR(4))
ELSE CAST(m.Missing + 1 AS NVARCHAR(4)) + '-' + CAST(mNext.Missing - 1 AS NVARCHAR(4))
END
FROM Missing AS m
LEFT JOIN Missing AS mNext ON m.RowNumber = mNext.RowNumber - 1
FOR XML PATH('')), 1, 2, '') AS Result
, STUFF((
SELECT ', ' + CAST(MIN(do.Expected + do.Change - 1) AS NVARCHAR(4))
FROM DegreesOff AS do
WHERE do.Change > 0
GROUP BY do.Change
FOR XML PATH('')), 1, 2, '') AS Result_Miss

Answer 2

Try the following script:
DDL
CREATE TABLE Numbers
(
Value INT NOT NULL
);
INSERT INTO Numbers
VALUES (1), (2), (3), (4), (6), (7), (8), (9), (10), (12),(13);
Script
DECLARE #MinValue INT
DECLARE #MaxValue INT
DECLARE #Temp TABLE(MissingValues INT)
DECLARE #MissingValues VARCHAR(50)
SELECT #MinValue = MIN(Value),
#MaxValue = MAX(Value)
FROM Numbers
;WITH CTE AS
(
SELECT #MinValue Value
UNION ALL
SELECT Value + 1
FROM CTE
WHERE Value + 1 <= #MaxValue
)
INSERT INTO #Temp
SELECT CTE.Value
FROM CTE
LEFT JOIN Numbers N
ON CTE.Value = N.Value
WHERE N.Value IS NULL
OPTION (MAXRECURSION 1000)
SELECT #MissingValues =
STUFF(( SELECT ',' + CAST(MissingValues AS VARCHAR)
FROM #Temp
FOR XML PATH('')),1,1,'')
INSERT INTO #Temp
SELECT #MinValue - 1
UNION ALL
SELECT #MaxValue + 1
;WITH CTE AS
(
SELECT MissingValues,
ROW_NUMBER() OVER(ORDER BY MissingValues ASC) RN
FROM #Temp
)
,Ranges AS
(
SELECT CAST(T1.MissingValues + 1 AS VARCHAR) + '-' +
CAST(T2.MissingValues - 1 AS VARCHAR) Ranges
FROM CTE AS T1
INNER JOIN CTE AS T2
ON T1.RN = T2.RN - 1
)
SELECT STUFF(( SELECT ',' + R.Ranges
FROM Ranges R
FOR XML PATH('')),1,1,'') Result,
#MissingValues AS Result_Miss