Multi-Map indexes allow you to index data from multiple collections e.g. polymorphic data (check the example) or any common data between types.
AddMap method is used to map fields from a single collection e.g. Dogs. AddMapForAll gives you the ability to specify what fields will be indexed from a base class.
Let's assume that we have Dog and Cat classes, and both of them inherit from the class Animal:
{CODE-TABS} {CODE-TAB:csharp:Dog multi_map_1@Indexes/MultiMap.cs /} {CODE-TAB:csharp:Cat multi_map_2@Indexes/MultiMap.cs /} {CODE-TAB:csharp:Animal multi_map_3@Indexes/MultiMap.cs /} {CODE-TAB:csharp:IAnimal multi_map_6@Indexes/MultiMap.cs /} {CODE-TABS/}
Now we can define our index using AddMap or AddMapForAll in the following way:
{CODE-TABS} {CODE-TAB:csharp:AddMap multi_map_4@Indexes/MultiMap.cs /} {CODE-TAB:csharp:AddMapForAll multi_map_5@Indexes/MultiMap.cs /} {CODE-TABS/}
{CODE-TABS} {CODE-TAB:csharp:Query multi_map_7@Indexes\MultiMap.cs /} {CODE-TAB:csharp:DocumentQuery multi_map_8@Indexes\MultiMap.cs /} {CODE-TAB-BLOCK:sql:RQL} from index 'Animals/ByName' where Name = 'Mitzy' {CODE-TAB-BLOCK/} {CODE-TABS/}
Please read more in our dedicated article on indexing polymorphic data. This article can be found here.
Another great application of Multi-Map indexes is smart-search. To search for products, companies, or employees by their name, you need to define the following index:
{CODE multi_map_1_0@Indexes\MultiMap.cs /}
and query it using:
{CODE multi_map_1_1@Indexes\MultiMap.cs /}
{INFO Remember that all map functions must output objects with identical shape (field names have to match). /}