Single Step Retrieval¶

Important

Single Step Retrieval loads only a partial set of the related objects (default size of the retrieved related collection is 10). To load additional related objects, use the Relation Paging API .

This approach allows retrieval of a partial set of the related objects along with the parent object in a single findor findById request. Each relationship property (column) must be uniquely identified by name using the API documented below.

Retrieving a specific object with relations¶

Using DictionaryCustom Class

Non-blocking call:

Backendless.Data.Of( "TABLE-NAME" ).FindById( 
                  string objectId, 
                  IList<string> relations,
                  AsyncCallback<Dictionary<string, object>> responder )

Blocking call:

Dictionary<string, object> result = Backendless.Data.Of( "TABLE-NAME" ).FindById( 
                  string objectId, 
                  IList<string> relations )

Non-blocking call:

Backendless.Data.Of<E>().FindById( 
                  string objectId, 
                  IList<string> relations,
                  AsyncCallback<E> responder )

Blocking call:

E result = Backendless.Data.Of( "TABLE-NAME" ).FindById( 
                  string objectId, 
                  IList<string> relations )

Retrieving a collection of objects with relations¶

DataQueryBuilder queryBuilder = Backendless.DataQueryBuilder.Create();
queryBuilder.AddRelated( "RELATED-PROPERTY-NAME" );
queryBuilder.AddRelated( "RELATED-PROPERTY-NAME.RELATION-OF-RELATION" );

Then load data using the constructed queryBuilder object with:

Using DictionaryCustom Class

Non-blocking call:

Backendless.Data.Of( "TABLE-NAME" ).Find( 
                  DataQueryBuilder queryBuilder, 
                  AsyncCallback<IList<Dictionary<string, object>>> callback  )

Blocking call:

IList<Dictionary<string, object>> result = Backendless.Data.Of( "TABLE-NAME" ).Find( 
                                                               DataQueryBuilder queryBuilder )

Non-blocking call:

Backendless.Data.Of<E>().Find( 
                  DataQueryBuilder queryBuilder, 
                  AsyncCallback<IList<E>> callback  )

Blocking call:

IList<E> result = Backendless.Data.Of<E>().Find( DataQueryBuilder queryBuilder )

where

Argument	Description
`RELATED-PROPERTY-NAME`	name of a related property to load. For example, if table `Person` has a relation "`homeAddress`" pointing to an object in the `Address` table, the value would be "`homeAddress`". The syntax allows to add relations of relations. For example, if the same `Address` table has a relation "`country`" pointing to the `Country` table, then "`homeAddress.country`" would instruct the related `Country` object to be loaded as well.
`queryBuilder`	an instance of the `DataQueryBuilder` class. The class is used to identify related properties for relation retrieval.
`TABLE-NAME`	Name of the table where the data should be retrieved from.
`E`	Reference to a class which identifies a table where the data should be loaded from.