问题
How to apply filtering conditions on expanded entities in OData ?
Suppose I have master entity as home having fields
homeId, StateId, CountyID, Address
and sub entities state as
StateId, StateName
and county as
CountyID, CountyName
I need to get the home addresses and Ids with a filter condition with state name and county name. How should be the url?
回答1:
Using the $expand keyword OData query should be something like:
/home/?$filter=state/statename eq 'STATE' and county/countyname eq 'COUNTY'&$expand=state,county&$select=homeId, Address
回答2:
I suspect your home entity type doesn't actually have navigation properties on it. In OData, if you want to connect two entities, you would create a property whose type matches the entity you want to link to. These properties (i.e., properties whose type is an entity type) are called navigation properties. If you want home to have an associated state, your home type would have a property called "State" or something like that, and that property would be of type state. Think of object-oriented programming instead of join-able IDs you would use in a relational database.
Similarly, home should have a property with type county if you want to connect a home entity to a county entity. Once you have navigation properties called "state" and "county", eoghank's answer should work for you.
回答3:
I have the same issue and i use the relational schema that links the two entities but even so only primary keys of expanded entity can be filtered or selected. I don't know how to call a diferent field that's not a primary key. See the following question: Question
来源：https://stackoverflow.com/questions/18124058/filter-on-expanded-entities-in-odata