MapInfo

@Target(allowedTargets = [AnnotationTarget.FUNCTION])
@Retention(value = AnnotationRetention.BINARY)
public annotation MapInfo

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")
fun getArtistNameToSongNames(): Map<String, List<String>>

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

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 MapInfo(
    @NonNull String keyColumn,
    @NonNull String keyTable,
    @NonNull String valueColumn,
    @NonNull String valueTable
)

public final @NonNull String getKeyColumn()

public final @NonNull String getKeyTable()

public final @NonNull String getValueColumn()

public final @NonNull String getValueTable()