LINQ CRM 2011 Update - Create

I notice the the CRM moderator David Jennaway on the technet forum states that you can't use LINQ to update/Create records in CRM 2011 see here http://social.microsoft.com/Forums/en-IE/crmdevelopment/thread/682a7be2-1c07-497e-8f58-cea55c298062

But I have seen a few threads that make it seem as if it should work. Here is my attempt which doesn't work. Any ideas why not?

IOrganizationServiceFactory serviceFactory = (IOrganizationServiceFactory)serviceProvider.GetService(typeof(IOrganizationServiceFactory));
IOrganizationService service 开发者_StackOverflow社区= serviceFactory.CreateOrganizationService(context.UserId);
OrganizationServiceContext orgContext = new OrganizationServiceContext(service);

EntityState state = new EntityState();
state = EntityState.Changed;

var counter = from c in orgContext.CreateQuery<pcx_entitycounter>()
        where c.pcx_name.Contains("pcx_candidate")
        select new pcx_entitycounter
        {Id = c.Id,
        pcx_name = c.pcx_name, pcx_Sequence = c.pcx_Sequence, pcx_Prefix = c.pcx_Prefix

        };

foreach (var c in counter)
        {
            string prefix = c.pcx_Prefix.ToString(); ;
            string sequence = c.pcx_Sequence.ToString();

            c.pcx_Sequence = c.pcx_Sequence + 1;
            c.EntityState = state;
            **service.Update(c);**  //FAILS HERE

        }

In my experience, it's been difficult-to-impossible to retrieve an entity from the Context, update it, then use the Service to save the changes. It has caused me headaches figuring it out!

Since your retrieval code uses a query from the Context, all of those entities should be attached to the Context and their states are being tracked. Thus you need to use the Context's method for updating:

foreach (var c in counter) {
    string prefix = c.pcx_Prefix.ToString(); ;
    string sequence = c.pcx_Sequence.ToString();

    c.pcx_Sequence = c.pcx_Sequence + 1;

    // Use the Context to save changes
    orgContext.UpdateObject(c);
    orgContext.SaveChanges();
}

Since a lot of my code will retrieve entities in different ways (i.e. Service or Context) depending on the situation, I have developed a simple method that knows how to update the entity correctly. To expand on your example, you might have an update method that looks like:

public void UpdatePcxEntityCounter(pcx_entitycounter c) {
    if (!orgContext.IsAttached(c)) {
        service.Update(c);
    }
    else {
        orgContext.UpdateObject(c);
        orgContext.SaveChanges();
    }
}

This assumes both orgContext and service are available at a scope above that of the method. Otherwise, they'd have to be passed as additional parameters.

Without seeing the difficult its difficult to discern what the issue is but have you tried using orgContext.UpdateObject(c); before doing the update step? Also, not sure why you are assigning the prefix and sequence to local variables within your loop since they don't appear to be being used. Its possible that you are getting a SOAP Exception or something for assigning values that don't work. Do you have any plugins registered on the entity?

See the following links for possible resolutions -

How to update a CRM 2011 Entity using LINQ in a Plugin?

http://social.microsoft.com/Forums/en-US/crmdevelopment/thread/7ae89b3b-6eca-4876-9513-042739fa432a