SQL 2012: Import DB changes original data scheme

Question

I'm migrating data from SQL 2008 R2 Servers to SQL 2012. Therefore I'm using SSMS Import Data Task on the SQL 2012 machines.

As a test I copied the data files of one of the DBs, did an "Attach Database" and a schema compare with the latest SQL Server Data Tools.

The diff from the attached vs. the imported-one seems just wrong. As an example:

Attached:

CREATE TABLE [dbo].[DbEventMessages] (
[EventID]         INT            IDENTITY (1, 1) NOT NULL,
[EntityType]      NVARCHAR (MAX) NOT NULL,
[ContactId]       INT            NOT NULL,
[Action]          NVARCHAR (MAX) NOT NULL,
[DateTime]        DATETIME2 (7)  NOT NULL,
[InnoVersionType] ROWVERSION     NULL,
CONSTRAINT [PK_DbDbEventMessages] PRIMARY KEY CLUSTERED ([EventID] ASC)
);
GO

Imported:

CREATE TABLE [dbo].[DbEventMessages] (
[EventID]         INT            NOT NULL,
[EntityType]      NVARCHAR (MAX) NOT NULL,
[ContactId]       INT            NOT NULL,
[Action]          NVARCHAR (MAX) NOT NULL,
[DateTime]        DATETIME2 (7)  NOT NULL,
[InnoVersionType] ROWVERSION     NOT NULL
);
GO

The imported scheme differs in

• the IDENTITY property on the key column
• the ROWVERSION was changed from NOT NULL to NULL
• the primary key constraint is missing

What is wrong here? Or is it working correctly? Thanks for any comments..

Answer 1

Take a backup of the SQL Server 2008 databases and restore it on SQL Server 2012. It is a much faster and reliable approach to migrating a database. Do not attach files between the instances, the SQL Server 2012 will upgrade them to a new format and you will loose the ability to use them again on SQL Server 2008.

As a general advice try to follow the procedures and guidelines, including the pre-migration validation steps from Upgrade to SQL Server 2012

Make sure you migrate all login information and SQL Agent jobs relevant for your database(s).