I can add a edit/delete button on the Grid and automatically have update support as well.

linqdatasource updating row not found or changed-90

NET control that implements the Data Source Control pattern introduced with ASP. It is similar to the Object Data Source and Sql Data Source controls in that it can be used to declaratively bind other ASP. Where it differs is that instead of binding directly to a database (like the Sql Data Source) or to a generic class (like the Object Data Source), the on my page that points to my LINQ to SQL datacontext class, and identify the entities (for example: Products) in the LINQ to SQL data model I want to bind against.

I could then point a Grid View at it (by settings its Data Source ID property) to get a grid-like view of the Product content: Without having to-do anything else, I can run the page and have a listing of my Product data with built-in support for paging and sorting over the data.

Your table has a blob (image in sql server, whatever) that is not nullable. I had this issue even when the database schema and dbml matched exactly.

The user chooses to update the record with the exact same image that is already there. The issue was I was trying to change an entity and insert entities in a single Submit Changes statement.

Ask yourself what would break or slow down significantly if you were to put strict transactional locks on your objects, and that will probably point you to the offending code.

My solution to this is to keep my unit of work as small as possible.

Ask yourself this, what if you put a locking transaction on your data for the whole lifetime of your objects.

If the underlying data changes in the meantime, it gets mad.

Submit Changes(Conflict Mode failure Mode) Every time I've seen this error, it means that something changed in the database between the time that I loaded the record/object/whatever and when I was trying to save it.