1.15 Implement ContentProvider delete() method

app/src/main/java/com/example/android/pets/data/PetProvider.java

@@ -175,11 +175,6 @@ private Uri insertPet(Uri uri, ContentValues values) {
  return ContentUris.withAppendedId(uri, id);
  }
 
- @Override
- public int delete(Uri uri, String s, String[] strings) {
- return 0;
- }
-
  @Override
  public int update(Uri uri, ContentValues contentValues, String selection,
  String[] selectionArgs) {
@@ -246,4 +241,24 @@ private int updatePet(Uri uri, ContentValues values, String selection, String[]
  // Returns the number of database rows affected by the update statement
  return database.update(PetEntry.TABLE_NAME, values, selection, selectionArgs);
  }
+
+ @Override
+ public int delete(Uri uri, String selection, String[] selectionArgs) {
+ // Get writeable database
+ SQLiteDatabase database = mDbHelper.getWritableDatabase();
+
+ final int match = sUriMatcher.match(uri);
+ switch (match) {
+ case PETS:
+ // Delete all rows that match the selection and selection args
+ return database.delete(PetEntry.TABLE_NAME, selection, selectionArgs);
+ case PET_ID:
+ // Delete a single row given by the ID in the URI
+ selection = PetEntry._ID + "=?";
+ selectionArgs = new String[] { String.valueOf(ContentUris.parseId(uri)) };
+ return database.delete(PetEntry.TABLE_NAME, selection, selectionArgs);
+ default:
+ throw new IllegalArgumentException("Deletion is not supported for " + uri);
+ }
+ }
 }