Filtering Entities with type Entity Reference?

Question

How do I query using the string value for an entity reference object?

QueryExpression query = new QueryExpression(\"entityName\");
query.Criteria = new FilterExp         


        

Answer 1

While it appears that we're out of luck on getting the "like" operator to compare a string to a GUID on the fly, there are at least a couple potential workarounds:

1. Retrieve all the GUID's, convert them to a list of strings, and find your subset by querying that list (i.e. with LINQ).
2. Write a very simple onCreate plugin or workflow that sets a new text field on the entity to the GUID. Then you have the GUID as a string, to work with as you please.

Here's code I use in a workflow that does exactly what I'm describing (i.e. populates the GUID into a text field). It sets an output parameter to the GUID, then the next step of the workflow populates that value into the field.

public partial class GetGuid : BaseWorkflow
{
    [Output("Entity Id")]
    public OutArgument<string> EntityId { get; set; }

    protected override void ExecuteInternal(LocalWorkflowContext context)
    {
        EntityId.Set(context.CodeActivityContext, context.WorkflowContext.PrimaryEntityId.ToString());
    }
}

Please also note that while the "like" operator doesn't work for GUID's, "greater than" and "less than" do, so something like this works:

<fetch>
    <entity name="account" >
        <attribute name="accountid" />
        <attribute name="name" />
        <filter type="and" >
            <condition attribute="accountid" operator="gt" value="14000000-0000-0000-0000-000000000000" />
        </filter>
    </entity>
</fetch>

Answer 2

parentaccountid is a Lookup Property .

LinkEnitity can only be applied for another entities.

The easy way for filtering is adding name at the end of attribute.

query.Criteria.AddCondition("parentaccountidname", ConditionOperator.Like, "%In%");

Thanks to Dave, refer here for Q&A

Answer 3

You need to filter on the name attribute of the associated account entity.

Join the account entity to the opportunity entity and apply a ConditionExpression to it like this:

var query = new QueryExpression("opportunity");
LinkEntity link = query.AddLink("account", "parentaccountid", "accountid");
link.AddCondition("name", ConditionOperator.BeginsWith, "14");