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Delete

public abstract @interface Delete
implements Annotation

androidx.room.Delete

Marks a method in a Dao annotated class as a delete method.

The implementation of the method will delete its parameters from the database.

All of the parameters of the Delete method must either be classes annotated with Entity or collections/array of it.

Example: 

 @Dao
 public interface MusicDao {
     @Delete
     public void deleteSongs(Song... songs);

     @Delete
     public void deleteAlbumAndSongs(Album album, List<Song> songs);
 }
If the target entity is specified via entity() then the parameters can be of arbitrary POJO types that will be interpreted as partial entities. For example: 
 @Entity
 public class Playlist {
   @PrimaryKey
   long playlistId;
   long ownerId;
   String name;
   @ColumnInfo(defaultValue = "normal")
   String category;
 }

 public class OwnerIdAndCategory {
   long ownerId;
   String category;
 }

 @Dao
 public interface PlaylistDao {
   @Delete(entity = Playlist.class)
   public void deleteByOwnerIdAndCategory(OwnerIdAndCategory... idCategory);
 }

See also:

Summary

Public methods

Class<?> entity()

The target entity of the delete method.

Inherited methods

Public methods

entity

public Class<?> entity ()

The target entity of the delete method.

When this is declared, the delete method parameters are interpreted as partial entities when the type of the parameter differs from the target. The POJO class that represents the entity must contain a subset of the fields of the target entity. The fields value will be used to find matching entities to delete.

By default the target entity is interpreted by the method parameters.

Returns
Class<?> the target entity of the delete method or none if the method should use the parameter type entities.