Inverted Relation Retrieval¶
Backendless supports a special query syntax for loading a subset of child objects for a specific parent. Consider the following table schemas:
PhoneBook table:
Contact table:
Address table:
These tables will be used to demonstrate how to query Backendless for conditional related object retrieval.
The general structure of a whereClause query to load a collection of child objects for a specific parent object is:
ParentTableName[ relatedColumnName ].parentColumnName COLUMN-VALUE-CONDITION
Both columns relatedColumnName
and parentColumnName
must be declared in a table with name of ParentTableName
. The relatedColumnName
must be a relation column. The table relatedColumnName
points to is the table where the objects must be loaded from.