SQL Grouping by first digit from sets of record - sql

Question

I need your help in SQL
I have a set of records of Cost center ID below.
what I want to do is to segregate/group them by inserting column to distinguish the category.
as you can see all digits start in 7 is belong to the bold digits.
my expected out is on below image also.

Answer 1

You can as the below:
DECLARE #Tbl TABLE (ID INT)
INSERT INTO #Tbl
VALUES
(735121201),
(735120001),
(5442244),
(735141094),
(735141097),
(4008060),
(735117603),
(40100000),
(735142902),
(735151199),
(4010070)
;WITH TableWithRowId
AS
(
SELECT
ROW_NUMBER() OVER (ORDER BY(SELECT NULL)) RowId,
ID
FROM
#Tbl
), TempTable
AS
(
SELECT T.RowId + 1 AS RowId FROM TableWithRowId T
WHERE
LEFT(T.ID, 1) != 7
), ResultTable
AS
(
SELECT
T.RowId ,
T.ID,
DENSE_RANK() OVER (ORDER BY (SELECT TOP 1 A.RowId FROM TempTable A WHERE A.RowId > T.RowId ORDER BY A.RowId)) AS Flag
FROM TableWithRowId T
)
SELECT * FROM ResultTable
Result:
RowId ID Flag
----------- ----------- ----------
1 735121201 1
2 735120001 1
3 5442244 1
4 735141094 2
5 735141097 2
6 4008060 2
7 735117603 3
8 40100000 3
9 735142902 4
10 735151199 4
11 4010070 4

Answer 2

The following query is similer with NEER's
;WITH test_table(CenterID)AS(
SELECT '735121201' UNION ALL
SELECT '735120001' UNION ALL
SELECT '5442244' UNION ALL
SELECT '735141094' UNION ALL
SELECT '735141097' UNION ALL
SELECT '4008060' UNION ALL
SELECT '735117603' UNION ALL
SELECT '40100000' UNION ALL
SELECT '735142902' UNION ALL
SELECT '735151199' UNION ALL
SELECT '4010070'
),t1 AS (
SELECT *,ROW_NUMBER()OVER(ORDER BY(SELECT 1)) AS rn,CASE WHEN LEFT(t.CenterID,1)='7' THEN 1 ELSE 0 END AS isSeven
FROM test_table AS t
),t2 AS(
SELECT t1.*,ROW_NUMBER()OVER(ORDER BY t1.rn) AS toFilter
FROM t1 LEFT JOIN t1 AS pt ON pt.rn=t1.rn-1
WHERE pt.CenterID IS NULL OR (t1.isSeven=1 AND pt.isSeven=0)
)
SELECT t1.CenterID,x.toFilter FROM t1
CROSS APPLY(SELECT TOP 1 t2.toFilter FROM t2 WHERE t2.rn<=t1.rn ORDER BY rn desc) x
CenterID toFilter
--------- --------------------
735121201 1
735120001 1
5442244 1
735141094 2
735141097 2
4008060 2
735117603 3
40100000 3
735142902 4
735151199 4
4010070 4