Microsoft SQL Server: Generate a sequence number, per day

Question

I\'m tasked to create an increasing sequence number per day for a project. Multiple processes (theoretically on multiple machines) need to generate this. It ends up as

Answer 1

I tried this way to create session codes for user logging and its working;

CREATE FUNCTION [dbo].[GetSessionSeqCode]()
RETURNS VARCHAR(15) 
AS
BEGIN
DECLARE @Count INT;
DECLARE @SeqNo VARCHAR(15)

SELECT @Count = ISNULL(COUNT(SessionCode),0)
FROM UserSessionLog
WHERE SUBSTRING(SessionCode,0,9) =  CONVERT(VARCHAR(8), GETDATE(), 112)

SET @SeqNo =  CONVERT(VARCHAR(8), GETDATE(), 112) +'-' + FORMAT(@Count+1,'D3');

RETURN @SeqNo
END

generated codes are: '20170822-001' ,'20170822-002' ,'20170822-003'