Grouping Sequential Numbers with like attributes

[NeoPa]

Would something like the following work ?

WITH ctePhone AS
(
SELECT ROW_NUMBER() OVER(Company
                       , PhoneType
                       , LD
                         ORDER BY Phone) AS SeqNo
     , Phone
     , Company
     , PhoneType
     , LD
FROM   @Phones
)
SELECT   MIN(Phone) AS First_Consecutive
       , CASE
         WHEN MIN(Phone) < MAX(Phone) THEN MAX(Phone)
         ELSE NULL
         END AS Last_Consecutive
       , MAX(SeqNo) - MIN(SeqNo) + 1 AS [Length]
       , Company
       , PhoneType
       , LD
FROM     ctePhone
GROUP BY Company
       , PhoneType
       , LD
ORDER BY MIN(Phone)

Obviously, I borrowed heavily from your work CK.

[Jerry Winston]

That's pretty CK.

[Joel Miller]

I was able to implement Jerry's solution into my code and it worked great! Thanks so much! I never would have gotten that done by myself and I learned a lot!

I have not been able to work on testing CK's or NEO's contributions but I am going to try that next.

Thanks everyone! This is one of the most helpful forums I have come across.

[NeoPa]

I've had some further thoughts on my suggestion and it appears there are situations where it would fall down. Specifically if the company etc details are the same for a bunch of records they will be treated as contiguous regardless of any breaks in the sequence.