I was working on a asp.net project when I realise I need to add an essential column to the sql database. I understand VS2010 doesn't support adding columns hence I attached the database(probably created with SQL2005express edition) to my SQL server 2008R2 and add it, after which I try to plug it(the same updated database) back to my project and got this error message when I try to open it up in the VS solution explorer:

"cannot be opened because it is version 661. This server supports version 655 and earlier. A downgrade path is not supported."

Could it be that my VS2010 is still configured to work with SQLExpress and not MSSQLSERVER because when I turn off the SQL Server (SQLEXPRESS) service in SQL Server configuration manager, VS solution explorer prompts an error upon trying to open any database:

"A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)."

Anyone can shed some light? I new to database development, any help is appreciated. All I want is just to add that single column. Thanks!

looks like a lot of things may have happened "under the covers" that you are not going to be too happy about. If the code migration is in fact by detach-reattach, then the SQL 2005 server is dead to this database. It can only be attached to a SQL2008 or higher database server. When you attach a database to a higher level SQL Instance (like attach a SQL 2005 database to a SQL 2008 instance), there is an automatic update to all of the page headers. Since very very few people go from SQL 2008 to SQL 2005, no one bothered to write an "undo" for this update.

Thanks for the reply, sorry if I interpret your answer wrongly, I am using SQL Server 2008R2, shouldn't I be able to open the "05 to 08 upgraded" database? That's why I was wondering if my VS2010 is somehow still working with SQL 2005 express edition and hence it was able to work with my database before updating but not after?

I am interpreting this as when you deploy back to the original source, you are getting this error. But yes, the error is caused when you try to attach the database to the wrong (lesser) version. Just a matter of figuring out where that version is, now.

Ok thanks, I am now trying to connect my VS2010 to my SQL Server 2008R2 instead of SQLEXPRESS, I have changed the instance name to 'MSSQLSERVER' without the quotes and this is my connectionstring:


<add name="ComEntities" connectionString="metadata=res://*/Data_Access.EDM_Com.csdl|res://*/Data_Access.EDM_Com.ssdl|res://*/Data_Access.EDM_Commerce.msl;provider=System.Data. SqlClient;provider connection string=&quot;Data Source=.\MSSQLSERVER;AttachDbFilename=|DataDirecto ry|\Database1.mdf;Integrated Security=True;User Instance=True;MultipleActiveResultSets=True&quot;" providerName="System.Data.EntityClient" />

I also disabled the SQLEXPRESS service and ran the MSSQLSERER service instead but now I am getting this error:

A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 25 - Connection string is not valid)

Any idea what am I doing wrong?

typically MSSQLSERVER indicates the default instance. Try with "Data Source=.", instead of "Data Source=.\MSSQLSERVER".