What is Difference between Retrieve VS Retrieverequest in SDK - use Retrieverequest to get related records using single server call

Which method will you apply to get related records of an entity record? 

Could we get it using service.retrieve? Probably you cannot... It will return single record but you may not get related records.

So how do you get it 

You can utilize Retrieverequest for this purpose. You can pass Relatedentity query as part of retrieve request which will return related entities as part of the response. 

Let us see some sample

if you want one specific incident record with its notes you can get it in a single server call.

Retrieve Method

Retrieve method used to get specific record by Id

C#

public override Entity Retrieve (             string entityName,             Guid id,             ColumnSet columnSet )

Parameters

^entityName

^{Type: String. The logical name of the entity specified in the entityId parameter.}

^id

^{Type: Guid. The ID of the record you want to retrieve.}

^columnSet

^{Type: ColumnSet. A query that specifies the set of columns, or attributes, to retrieve.}

Return Value

Type: Entity
The requested record. 

  

Sample Syntax:

Entity entity = crmservice.Retrieve("incident", new Guid("5181F7EA-914F-E411-91C6-0050569A023C"), new ColumnSet(true));

Retrieverequest

Retrieve method used to get specific record by Id including related entity instance in a single server call

Step 1: Define Related Entity request query. You can create multiple queries if required

QueryExpression OQueryExpression = new QueryExpression();

OQueryExpression.EntityName = "annotation";

OQueryExpression.ColumnSet = new ColumnSet(true);

Step 2:  Define relationshipquerycollection and add the Query expressions into it.

RelationshipQueryCollection OrelatioshipQueryCollection = new RelationshipQueryCollection();

Relationship Orelationship = new Relationship("Incident_Annotation");  //Schema Name of relationship

OrelatioshipQueryCollection.Add(Orelationship, OQueryExpression);

Step 3:  Define retrieve request object. define the Id of Case[incident] which you want to retrieve

RetrieveRequest OretrieveRequest = new RetrieveRequest();

OretrieveRequest.Target = new EntityReference("incident", new Guid("5181F7EA-914F-E411-91C6-0050569A023C"));

OretrieveRequest.ColumnSet = new ColumnSet(true);

Step 3:  Attach relationshipquerycollection to request

OretrieveRequest.RelatedEntitiesQuery = OrelatioshipQueryCollection;

Step 3:  Call service to retrieve

RetrieveResponse response=(RetrieveResponse)  service.Execute(OretrieveRequest);

How to read related entity records 

foreach (KeyValuePair<Relationship, EntityCollection> relatedEntitiesCollection in response.Entity.RelatedEntities)

   {

Relationship relationship = relatedEntitiesCollection.Key;

EntityCollection entityCollection = relatedEntitiesCollection.Value;

  for (int i = 0; i < entityCollection.Entities.Count;i++ )

     {

  Entity Oentity=  entityCollection.Entities[i];

    // Do your actions

                

      }

   }

   

Happy Coding!