How can I check a group of numbers are consecutive in T-SQL?

If i was to have a table with an integer column containing n number of rows and wanted to check if they were consecutive, how could I do this?

DECLARE @Temp TABLE 
(
    IntegerValue INT,
    Processed BIT
)

I have a solution that works for 3 rows but this is infelxable, if the requirements chan开发者_高级运维ge then so would the query (ignoring the fact that my sum wouldnt work in this case).

@SumOfValues = (@FirstValue * @NumOfValues) + @NumOfValues 

---

SELECT CASE
         WHEN COUNT(DISTINCT IntegerValue) /*Or COUNT(*) dependant on how
                                            duplicates should be treated */ 
                =  1 + MAX(IntegerValue) - MIN(IntegerValue) THEN 'Y'
         ELSE 'N'
       END
FROM   @Temp  

If you want to know where the gaps are you can use

;WITH T AS
(
SELECT *,
       DENSE_RANK() OVER (ORDER BY IntegerValue) - IntegerValue AS Grp
FROM @Temp
)
SELECT MIN(IntegerValue) AS RangeStart, 
       MAX(IntegerValue) AS RangeEnd
FROM T
GROUP BY Grp
ORDER BY MIN(IntegerValue)

---

CREATE TABLE #T(ID INT)
DECLARE @i INT
SET @I = 1
WHILE(@I <= LEN('12235588966'))
BEGIN
  IF(SUBSTRING('12235588966',@i,1) = SUBSTRING('12235588966',@i-1,1))
  BEGIN
        INSERT INTO #T SELECT SUBSTRING('12235588966',@i,1)
  END
  SET @i = @I +1
END

SELECT * FROM #T