MapInfo

public abstract @interface MapInfo
implements Annotation

Declares which column(s) are used to build a map or multimap return value in a Dao query method.

This annotation is required when the key or value of the Map is a single column of one of the built in types (primitives, boxed primitives, enum, String, byte[], ByteBuffer) or a type with a converter (e.g. Date, UUID, etc).

The use of this annotation provides clarity on which column should be used in retrieving information required by the return type.

Example:

   @MapInfo(keyColumn = "artistName", valueColumn = "songName")
   @Query("SELECT * FROM Artist JOIN Song ON Artist.artistName = Song.artist")
    Map<String, List<String>> getArtistNameToSongNames();

   @MapInfo(valueColumn = "songCount")
   @Query("SELECT *, COUNT(mSongId) as songCount FROM Artist JOIN Song ON
   Artist.artistName = Song.artist GROUP BY artistName")
    Map<Artist, Integer> getArtistAndSongCounts();
 

To use the @MapInfo annotation, you must provide either the key column name, value column name, or both, based on the Dao's method return type. Column(s) specified in the provided @MapInfo annotation must be present in the query result.

Summary

Public methods

public String keyColumn ()

public String valueColumn ()