1 /*
2  * Copyright 2022 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package androidx.room;
18 
19 /**
20  * Thrown by Room when the query in a Single<T> DAO method needs to return a result but the
21  * returned result from the database is empty.
22  * <p>
23  * Since a Single&lt;T&gt; must either emit a single non-null value or an error, this exception is
24  * thrown instead of emitting a null value when the query resulted empty. If the Single&lt;T&gt;
25  * contains a type argument of a collection (e.g. Single&lt;List&lt;Song&gt&gt;) then this
26  * exception is not thrown an an empty collection is emitted instead.
27  */
28 @SuppressWarnings("serial")
29 public class EmptyResultSetException extends RuntimeException {
30     /**
31      * Constructs a new EmptyResultSetException with the exception.
32      * @param message The SQL query which didn't return any results.
33      */
EmptyResultSetException(String message)34     public EmptyResultSetException(String message) {
35         super(message);
36     }
37 }
38