Inserting not calculated Id in table transact SQL - sql

Question

I have a stored procedure where I receive data as JSON from a API in C#. I insert the data into two tables like this:
INSERT INTO dbo.ServiceRequestHeader(SubscriptionId, CustomerAccountId, ModifiedBy)
OUTPUT Inserted.ServiceRequestHeaderId INTO #TempT
SELECT
SubscriptionId,
CustomerAccountId,
ModifiedBy
FROM
OpenJson(#JsonServiceRequest)
WITH
(SubscriptionId TinyInt,
CustomerAccountId Int)
SELECT #TempId = Id FROM #TempT
INSERT INTO dbo.ServiceRequest(ServiceRequestId, ServiceRequestHeaderId, SubscriptionId)
SELECT
#TempId, -- <= Here I need to modify the serviceRequestHeaderId
#TempId,
SubscriptionId
FROM
OpenJson(#JsonServiceRequest, '$.ServiceRequest')
WITH (SubscriptionId TinyInt,
...)
The thing is that the serviceRequestId is not a calculated field and it's a special case that depends on ServiceRequestHeaderId.
Example:
If ServiceRequestHeaderId = 1000 the ServiceRequestId would be 1000 001, 1000 002... N...
This is where I can't come with a way to do it

Answer 1

You can generate servicerequestids as given below. I am using FORMAT function with 000 for padding with 0 till 3 digits. If you want four digits, use 0000.
SELECT #TempId = Id FROM #TempT
INSERT INTO dbo.ServiceRequest(ServiceRequestId, ServiceRequestHeaderId, SubscriptionId)
SELECT
CONCAT(#TempId,FORMAT(ROW_NUMBER() OVER(ORDER BY (SELECT null)),'000')) AS ServiceRequestId, -- <= Here I need to modify the serviceRequestHeaderId
#TempId,
SubscriptionId
FROM
OpenJson(#JsonServiceRequest, '$.ServiceRequest')
WITH (SubscriptionId TinyInt,
...)
You will get something like below:
+------------------+
| ServiceRequestId |
+------------------+
| 1000001 |
| 1000002 |
| 1000003 |
+------------------+

Answer 2

Use a CTE to calculate a row number per request and then build the id from it e.g.
with MyCTE as (
select
SubscriptionId
-- Order by whatever makes business sense to you
, row_number() over (order by SubscriptionId) rn
from openjson(#JsonServiceRequest, '$.ServiceRequest')
with (
SubscriptionId tinyint,
...
)
)
insert into dbo.ServiceRequest (ServiceRequestId, ServiceRequestHeaderId, SubscriptionId)
-- Put whatever logic you like here to calculate a row number based id
select convert(varchar(4),#TempId) + ' ' + case when rn >= 100 then convert(varchar(3),rn) when rn > 10 then '0' + convert(varchar(2),rn) else '00' + convert(varchar(1),rn) end
, #TempId, SubscriptionId
from MyCTE;