How to make auto increment of an existing primary key in Azure?

Question

How to make auto increment of an existing primary key in Azure?

Answer 1

Your table has to be rebuild from scratch, it's not possible to assign an auto_increment to an existing table. Try this script, wich will build a table for you with auto_increment, transfer all the data from your old table to the new one, drops the old table and renames the new one to the old one.

Just make sure that your data is compatable with the auto_increment property!

BEGIN TRANSACTION
SET QUOTED_IDENTIFIER ON
SET ARITHABORT ON
SET NUMERIC_ROUNDABORT OFF
SET CONCAT_NULL_YIELDS_NULL ON
SET ANSI_NULLS ON
SET ANSI_PADDING ON
SET ANSI_WARNINGS ON
COMMIT
BEGIN TRANSACTION
GO
CREATE TABLE dbo.Tmp_schema_version
    (
    version int NULL,
    datetime datetime NULL,
    comments nvarchar(150) NULL,
    id int NOT NULL IDENTITY (1, 1)
    )  ON [PRIMARY]
GO
ALTER TABLE dbo.Tmp_schema_version SET (LOCK_ESCALATION = TABLE)
GO
SET IDENTITY_INSERT dbo.Tmp_schema_version ON
GO
IF EXISTS(SELECT * FROM dbo.schema_version)
     EXEC('INSERT INTO dbo.Tmp_schema_version (version, datetime, comments, id)
        SELECT version, datetime, comments, id FROM dbo.schema_version WITH (HOLDLOCK TABLOCKX)')
GO
SET IDENTITY_INSERT dbo.Tmp_schema_version OFF
GO
DROP TABLE dbo.schema_version
GO
EXECUTE sp_rename N'dbo.Tmp_schema_version', N'schema_version', 'OBJECT' 
GO
ALTER TABLE dbo.schema_version ADD CONSTRAINT
    PK_schema_version PRIMARY KEY CLUSTERED 
    (
    id
    ) WITH( STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]

GO
COMMIT

Answer 2

This is almost the similar way of @Dieter Gobeyn's solution; which I followed later.

Create the temp table with the auto increment on

CREATE TABLE [dbo].[schema_version_new](
    [ID] [int] IDENTITY(1,1) NOT NULL,  
    [Version] [int] NULL,
    [DateTime] [datetime] NULL,
    [Comments] [nvarchar](150) NULL,

    PRIMARY KEY CLUSTERED 
    (
        [ID] ASC
    )
    ) ON [PRIMARY]

GO

Copy everything from the old table to the newly created one; We left the ID intentionally behind from the old table and we've put auto increment ID on the the new table so don't need to put ID there. In case we need to preserve the IDs of the old table then we need to "SET IDENTITY_INSERT dbo.schema_version_new OFF", include the IDs while inserting rows and after inserting we turn identity_insert on again "SET IDENTITY_INSERT dbo.schema_version_new ON". For new insert it will get auto IDs.

INSERT INTO [schema_version_new]([Version], [Datetime], [Comments]) 
    SELECT [Version], [Datetime], [Comments] FROM [schema_version]

Drop the old table.

DROP TABLE [dbo].[schema_version]
GO

Rename the new table to the old table's name.

EXECUTE sp_rename N'dbo.schema_version_new', N'schema_version', 'OBJECT'
GO