List ranges and the total count based on condition - sql-server-2008-r2

Question

Table Schema
CREATE TABLE [dbo].[TblMaster](
[SID] [int] IDENTITY(1,1) NOT NULL Primary Key,
[VID] [int] NOT NULL,
[CreatedDate] [datetime] default (getdate()) NOT NULL,
[CharToAdd] [varchar](10) NULL,
[Start] [int] NOT NULL,
[End] [int] NOT NULL
)
GO
CREATE TABLE [dbo].[TblDetails](
[DetailsID] [int] IDENTITY(1,1) NOT NULL Primary Key,
[SID] [int] NOT NULL,
[Sno] [int] NOT NULL,
[ConcatenatedText] [varchar](20) NOT NULL,
[isIssued] [bit] default (0) NOT NULL,
[isUsed] [bit] default (0) NOT NULL
)
GO
Sample Data:
Insert into dbo.TblMaster Values (1,default, 'CA', 1, 5)
Insert into dbo.TblMaster Values (1,default, 'PA', 1, 5)
GO
Insert into dbo.TblDetails values(1, 1, 'CA1', 0,0)
Insert into dbo.TblDetails values(1, 2, 'CA2', 0,0)
Insert into dbo.TblDetails values(1, 3, 'CA3', 0,0)
Insert into dbo.TblDetails values(1, 4, 'CA4', 1,0)
Insert into dbo.TblDetails values(1, 5, 'CA5', 0,0)
Insert into dbo.TblDetails values(2, 1, 'PA1', 0,0)
Insert into dbo.TblDetails values(2, 2, 'PA2', 0,0)
Insert into dbo.TblDetails values(2, 3, 'PA3', 1,0)
Insert into dbo.TblDetails values(2, 4, 'PA4', 0,0)
Insert into dbo.TblDetails values(2, 5, 'PA5', 0,0)
Insert into dbo.TblDetails values(3, 1, '1', 0,0)
Insert into dbo.TblDetails values(3, 2, '2', 1,0)
Insert into dbo.TblDetails values(3, 3, '3', 1,0)
Insert into dbo.TblDetails values(3, 4, '4', 0,0)
Insert into dbo.TblDetails values(3, 5, '5', 0,0)
GO
Expected Output:
Query I have built as of now:
Declare #VID INT = 1
;WITH Tmp as
(
SELECT
TM.CharToAdd as Prefix,
sno,
sno - ROW_NUMBER() OVER(ORDER BY sno) as grp
FROM dbo.TblDetails TD
LEFT JOIN dbo.TblMaster TM on TM.[SID] = TD.[SID]
WHERE isIssued = 0 and isUsed = 0
AND TM.VID = #VID
)
SELECT Prefix,
MIN(sno) as RangeStart,
MAX(sno) as RangeEnd,
COUNT(*) as [Count]
FROM Tmp
GROUP BY grp, Prefix
In the TblDetails table want to find the range of available values and its total counts from all records whose bit columns are 0. If bit column is 1 then it means it is already used so I am trying to skip it and list rest as available records. Doubtful whether am I explaining the problem statement well so have provided the sample data and expected output for better understanding. I did try doing some recursive function but the result isn't matching the expected output. So looking for help to resolve this.

Answer 1

You were very close...
CODE
Declare #VID INT = 1
;with cte as(
select
m.CHarToAdd,
d.sno,
d.sno - ROW_NUMBER() OVER(partition by m.CharToAdd ORDER BY sno) as grp
from
TblMaster m
inner join
TblDetails d on
d.sid = m.sid
where
d.isIssued = 0 and d.isUsed = 0 and m.vid = #VID)
select
CharToAdd,
min(sno) as Start,
max(sno) as [End],
(max(sno) - min(sno) + 1) as [Count]
from cte
group by
CHarToAdd, grp
order by
CHarToAdd
RESULTS
CharToAdd Start End Count
CA 1 3 3
CA 5 5 1
PA 1 2 2
PA 4 5 2