CRM 2011 KeyNotFoundException exception

Question

I am new to CRM development. I have a Custom Entity "customer". This Entity has a Field called "defaultcustomer", which can be TRUE or FALSE. I am working on a Plug-In where i need to set the "defaultcustomer" to FALSE for all the "Customers". I am doing it as below:

FACTS:

I have registered the plugin for the entity "customer" itself. So when the Entity "customer" is updated, the plugin fires.

private void MakeAllNonDefault()
{

    try
    {
        QueryExpression query = new QueryExpression("customer");
        query.ColumnSet = new ColumnSet("defaultcustomer");

        EntityCollection retrieved = service.RetrieveMultiple(query);

        foreach (Entity myCustomer in retrieved.Entities)
        {

            myCustomer["defaultcustomer"] = false;
            service.Update(myCustomer);
        }

    }
    catch (Exception ex)
    {
        throw new InvalidPluginExecutionException("An error occurred in MakeAllNonDefault(): " + ex.ToString());
    }
}

ERROR: It throws error on this line:

myCustomer["defaultcustomer"] = false;

System.Collections.Generic.KeyNotFoundException: 
The given key was not present in the dictionary. 

Answer 1

The error means that particular field is not present in the collection of properties. In CRM, only properties that have been set or updated are included.

Try something like:

foreach (Entity myCustomer in retrieved.Entities)
{
    if (myCustomer.Attributes.ContainsKey("defaultcustomer"))
    {
        myCustomer["defaultcustomer"] = false;
    }
    else
    {
        myCustomer.Attributes.Add("defaultcustomer", false);
    }
    service.Update(myCustomer);
}