VS2010, SqlCE 4.0 not a data source option (only 3.5)

With installed: VS2010, SqlCE 4.0 CTP2;

When adding a datasource, in the "Entity Data Model Wizard" > "New Connection"; There is Sql Server Compact 3.5, but not 4.0. (Same for chosing Dataset). Shouldn't it show 4.0 here, or does it matter at all, will the .sdf files be the same 开发者_运维百科as 3.5/4.0?

A SqlCE 4.0 database won't work with the Sql Server Compact 3.5 data source connections.

Design time support for SqlCE 4.0 is available in Visual Studio SP1 which was released as a Beta Version at the start of December 2010.

See these blog posts from Scott Guthrie & Scott Hanselman on some new features and bug fixes in VS2010 SP1

You can download VS2010 SP1 Beta from here but remember that it is a Beta version and shouldn't really be used in a production environment!

A comprehensive list of what is new in VS2010 SP1 can be found here

SQL CE 4.0 is not good choice.

The most problem of CE4 is that we cannot reorder the column after created the table. Also we cannot insert a new column between each other.

This result every time when we have to Export the data , DROP and CREATE the table and import data again.

I stumbled into the same problem!
The solution is easy. Just add a dependency to System.Data.SqlServerCe that points to 4.0 (not 3.5) to your project.

You may also find it helpful http://sqlcetoolbox.codeplex.com/

Ah, seems answer is here. SqlCE 4.0 only supported for "Web Project"... rrg