Id auto increment varchar not increments - sql-server

Question

I am using a VARCHAR column as my primary key. I want to auto increment it (base 62, lower/upper case, numbers), However, the below code fails (for obvious reasons):
CREATE TABLE TESTING
(
ID VARCHAR(10),
NAME VARCHAR(15),
DESCP VARCHAR(50)
);
Creating a procedure for testing insert of a new record with NVARCHAR auto-incremented ID:
CREATE PROCEDURE SP_INSERT
#NAME VARCHAR(MAX), #DESCP VARCHAR(MAX)
AS
BEGIN
/* Logic for getting new ID as per the NAME with PRE FIX */
DECLARE #NEWID VARCHAR(5);
DECLARE #PREFIX VARCHAR(10);
SET #PREFIX = UPPER(SUBSTRING('STR', 1, 3))
SELECT #NEWID = (#PREFIX + replicate('0', 3 - len(CONVERT(VARCHAR, N.OID 1))) + CONVERT(VARCHAR, N.OID + 1))
FROM
(SELECT
CASE
WHEN MAX(T.TID) IS NULL
THEN 0 ELSE MAX(T.TID)
END AS OID
FROM
(SELECT SUBSTRING(ID, 1, 1) AS PRE_FIX,
SUBSTRING(ID, 2, LEN(ID)) AS TID
FROM Testing) AS T
WHERE
T.PRE_FIX = #PREFIX) AS N
/* INSERT QUERY FOR NEW RECORD */
INSERT INTO Testing VALUES (#NEWID, #NAME, #DESCP)
END
I try to insert a values:
SP_INSERT 'svce','YOUR MANAGEMENT DESCRIPTION';
this first time, again try to inset I got same ID is not incremented.
Like:
ID Name
------------
SVC001 SVCE
SVC001 Svce

Answer 1

You could try to use COMPUTED COLUMN something like that:
create table t
(
Id int auto_increment,
ComputedId as 'SVC' + convert(nvarchar(60), lpad(Id,3,'0')),
Data nvarchar(60)
)

Answer 2

I MADE ONE SMALL SCRIPT,
declare #t table (id varchar(10))
insert into #t values ('SVC001'),('SVC20902')
Declare #NEWID int
select #NEWID=isnull(max(replace(id,'SVC',''))+1,1) from #t
select 'SVC'+ replicate('0',CASE WHEN 3-len(#NEWID)<=0
THEN 0 ELSE 3-len(#NEWID) END)+cast(#NEWID as varchar(10))

Answer 3

Finally I got solution for Auto_Increment ID. I done following code for solution. code is:
alter PROCEDURE SP2_INSERT
#NAME VARCHAR(MAX),
#DESCP VARCHAR(MAX)
AS
BEGIN
DECLARE #NEWID VARCHAR(10);
DECLARE #PREFIX VARCHAR(MAX);
SET #PREFIX = UPPER(SUBSTRING(#NAME,1, 3))
SELECT #NEWID = (#PREFIX + replicate('0', 3 - len(CONVERT(VARCHAR,N.OID + 1))) + CONVERT(VARCHAR,N.OID + 1)) FROM (
SELECT CASE WHEN MAX(T.TID) IS null then 0 else MAX(T.TID) end as OID FROM (
SELECT SUBSTRING(EmployeeID, 1, 1) as PRE_FIX,SUBSTRING(EmployeeID, 2, LEN(EmployeeID)) as TID FROM EmployeeMasters
) AS T WHERE T.PRE_FIX = #PREFIX
) AS N
INSERT INTO Testing VALUES (#NEWID,#NAME,#DESCP)
end

Answer 4

Try this,
DECLARE #table TABLE(ID VARCHAR(10),
NAME VARCHAR(15),
DESCP VARCHAR(50))
DECLARE #NEWID VARCHAR(5);
DECLARE #PREFIX VARCHAR(10);
SET #PREFIX = UPPER(SUBSTRING('STR', 1, 3))
SELECT #NEWID=CAST(ISNULL(MAX(CAST(SUBSTRING(ID,4,LEN(ID)) AS INT)),0)+1 AS varchar) FROM #table
INSERT INTO #table(DESCP,ID,NAME)
SELECT 'zzzz',(#PREFIX + replicate('0', 3 - len(CONVERT(VARCHAR,#NEWID))))+#NEWID,'fsf'
SELECT #NEWID=CAST(ISNULL(MAX(CAST(SUBSTRING(ID,4,LEN(ID)) AS INT)),0)+1 AS varchar) FROM #table
INSERT INTO #table(DESCP,ID,NAME)
SELECT 'zzzz',(#PREFIX + replicate('0', 3 - len(CONVERT(VARCHAR,#NEWID))))+#NEWID,'fsf'
SELECT * FROM #table