Stored procedure to generate sequential guid for all tables - tsql

Question

This may well be a duplicate but I can't seem to find anything close enough to my use case.
Due to various reasons like views, instead of triggers and so on, I'm unable to use the OUTPUT clause with an INSERT statement to retrieve the system generated GUID with NEWSEQUENTIALID().
An idea which I have, is to rather generate the GUID using a stored procedure:
SET NOCOUNT ON;
GO
IF ( OBJECT_ID( N'[dbo].[GETNEXTGUID]' ) IS NOT Null )
DROP PROCEDURE [dbo].[GETNEXTGUID];
GO
CREATE PROCEDURE [dbo].[GETNEXTGUID]
(#NextId UNIQUEIDENTIFIER OUTPUT)
AS
BEGIN
SET NOCOUNT ON;
DECLARE #Sequence TABLE([KEY] UNIQUEIDENTIFIER NOT NULL DEFAULT NEWSEQUENTIALID(), [DUMMY] BIT);
INSERT INTO #Sequence ([DUMMY]) VALUES (0);
SELECT #NextId = [KEY] FROM #Sequence;
END
GO
DECLARE #NextId UNIQUEIDENTIFIER;
EXECUTE [dbo].[GETNEXTGUID] #NextId OUTPUT;
PRINT #NextId;
The generated GUID can then be inserted into the table and should also alleviate the issue that plagues IDENTITY columns with ##IDENTITY, IDENT_CURRENT, etc.
I don't have sufficient knowledge even after testing to authoritatively say whether this is truly a working solution or simply a long winded way of applying a "somewhat" cleaner NEWID() due to the fact that it's using a temp table which is being destroyed after every call.
I tried using TWO temp tables and their sequential numbers seem to tie up and running the procedure consecutively also seems to tie up.
SET NOCOUNT ON;
GO
IF (OBJECT_ID( N'[dbo].[GETNEXTGUID]') IS NOT Null)
DROP PROCEDURE [dbo].[GETNEXTGUID];
GO
CREATE PROCEDURE [dbo].[GETNEXTGUID]
(#NextId1 UNIQUEIDENTIFIER OUTPUT,
#NextId2 UNIQUEIDENTIFIER OUTPUT)
AS
BEGIN
SET NOCOUNT ON;
DECLARE #Sequence1 TABLE ([KEY] UNIQUEIDENTIFIER NOT NULL DEFAULT NEWSEQUENTIALID(), [DUMMY] BIT);
DECLARE #Sequence2 TABLE ([KEY] UNIQUEIDENTIFIER NOT NULL DEFAULT NEWSEQUENTIALID(), [DUMMY] BIT);
INSERT INTO #Sequence1 ([DUMMY]) VALUES (0);
INSERT INTO #Sequence2 ([DUMMY]) VALUES (0);
SELECT #NextId1 = [KEY] FROM #Sequence1;
SELECT #NextId2 = [KEY] FROM #Sequence2;
END
GO
DECLARE #NextId1 UNIQUEIDENTIFIER;
DECLARE #NextId2 UNIQUEIDENTIFIER;
EXECUTE [dbo].[GETNEXTGUID] #NextId1 OUTPUT, #NextId2 OUTPUT;
PRINT #NextId1; PRINT #NextId2;
EXECUTE [dbo].[GETNEXTGUID] #NextId1 OUTPUT, #NextId2 OUTPUT;
PRINT #NextId1; PRINT #NextId2;
EXECUTE [dbo].[GETNEXTGUID] #NextId1 OUTPUT, #NextId2 OUTPUT;
PRINT #NextId1; PRINT #NextId2;
EXECUTE [dbo].[GETNEXTGUID] #NextId1 OUTPUT, #NextId2 OUTPUT;
PRINT #NextId1; PRINT #NextId2;
EXECUTE [dbo].[GETNEXTGUID] #NextId1 OUTPUT, #NextId2 OUTPUT;
PRINT #NextId1; PRINT #NextId2;
Result:
AAAFD869-E814-EA11-A2FA-00155D0A020C
ABAFD869-E814-EA11-A2FA-00155D0A020C
ACAFD869-E814-EA11-A2FA-00155D0A020C
ADAFD869-E814-EA11-A2FA-00155D0A020C
AEAFD869-E814-EA11-A2FA-00155D0A020C
AFAFD869-E814-EA11-A2FA-00155D0A020C
B0AFD869-E814-EA11-A2FA-00155D0A020C
B1AFD869-E814-EA11-A2FA-00155D0A020C
B2AFD869-E814-EA11-A2FA-00155D0A020C
B3AFD869-E814-EA11-A2FA-00155D0A020C
I'd appreciate input from someone with more experience offering their insights.

Answer 1

I do not know, what you really need, but you might try something along this:
CREATE SEQUENCE dbo.testSeq_13Byte AS DECIMAL(28); /*read about START WITH to enforce a range*/
GO
SELECT NEXT VALUE FOR dbo.testSeq_13Byte;
GO
SELECT CAST(CAST(NEXT VALUE FOR dbo.testSeq_13Byte AS VARBINARY(16)) AS UNIQUEIDENTIFIER);
According to the docs a DECIMAL(28) takes 13 bytes, a DECIMAL(38) lives in 17 bytes and a GUID is using 16 bytes.
The numeric range of DECIMAL(28) is huge... you can cast this to VARBINARY(16) and this to UNIQUEIDENTIFIER. This should return a new id with a system-wide logic.
If you need this, you might even cast this back to a DECIMAL(28).
But we should keep in mind, that it is always a bit dangerous to rely on the internal binary representation of a datatype. This might change from version to version...

Answer 2

So I created the following stored procedure to test with. It creates 2 temp tables which will show whether the id's generated are in fact sequential.
SET NOCOUNT ON;
GO
IF (OBJECT_ID( N'[dbo].[GETNEXTGUID]') IS NOT Null)
DROP PROCEDURE [dbo].[GETNEXTGUID];
GO
CREATE PROCEDURE [dbo].[GETNEXTGUID]
(
#NextId1 UNIQUEIDENTIFIER OUTPUT,
#NextId2 UNIQUEIDENTIFIER OUTPUT
)
AS
BEGIN
SET NOCOUNT ON;
DECLARE #Sequence1 TABLE ([KEY] UNIQUEIDENTIFIER NOT NULL DEFAULT NEWSEQUENTIALID(), [DUMMY] BIT);
DECLARE #Sequence2 TABLE ([KEY] UNIQUEIDENTIFIER NOT NULL DEFAULT NEWSEQUENTIALID(), [DUMMY] BIT);
INSERT INTO #Sequence1 ([DUMMY]) VALUES (0);
INSERT INTO #Sequence2 ([DUMMY]) VALUES (0);
SELECT #NextId1 = [KEY] FROM #Sequence1;
SELECT #NextId2 = [KEY] FROM #Sequence2;
END
GO
I then ran the following test across multiple connections at the same time. So the test will call it's own two persisted tables as well as the two temp tables within the stored procedure.
SET NOCOUNT ON;
GO
DECLARE #Sequence1 TABLE ([KEY] UNIQUEIDENTIFIER NOT NULL DEFAULT NEWSEQUENTIALID(), [DUMMY] BIT);
DECLARE #Sequence2 TABLE ([KEY] UNIQUEIDENTIFIER NOT NULL DEFAULT NEWSEQUENTIALID(), [DUMMY] BIT);
DECLARE #Count int = 0;
DECLARE #NextId1 UNIQUEIDENTIFIER;
DECLARE #NextId2 UNIQUEIDENTIFIER;
WHILE ( #Count < 100000 )
BEGIN
EXECUTE [dbo].[GETNEXTGUID] #NextId1 OUTPUT, #NextId2 OUTPUT;
PRINT #NextId1; PRINT #NextId2;
INSERT INTO #Sequence1 ([DUMMY]) VALUES (0);
INSERT INTO #Sequence2 ([DUMMY]) VALUES (0);
SELECT #NextId1 = [KEY] FROM #Sequence1;
SELECT #NextId2 = [KEY] FROM #Sequence2;
PRINT #NextId1; PRINT #NextId2;
SET #Count += 1;
END
GO
Taking the results from the various connections and sorting them showed that the sequence is sequential across all 4 tables, regardless of whether they're persisted or recreated with each call and therefore will fit the requirement perfectly.
Thanks for the input everyone!