Fix Native Query projections mapping to DTOs.

We now provide the target type to createNativeQuery(…) if we detect that a native query result type is a projection and not an interface.

Closes #2757

Author: mp911de

spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/query/NativeJpaQuery.java

@@ -93,8 +93,15 @@ private Class<?> getTypeToQueryFor(ReturnedType returnedType) {
 			return result;
 		}
 
-		return returnedType.isProjecting() && !getMetamodel().isJpaManaged(returnedType.getReturnedType()) //
-				? Tuple.class
-				: result;
+		if (returnedType.isProjecting()) {
+
+			if (returnedType.getReturnedType().isInterface()) {
+				return Tuple.class;
+			}
+
+			return returnedType.getReturnedType();
+		}
+
+		return result;
 	}
 }

spring-data-jpa/src/test/java/org/springframework/data/jpa/repository/UserRepositoryTests.java

@@ -67,6 +67,7 @@
 import org.springframework.data.jpa.domain.sample.Role;
 import org.springframework.data.jpa.domain.sample.SpecialUser;
 import org.springframework.data.jpa.domain.sample.User;
+import org.springframework.data.jpa.repository.sample.NameOnlyRecord;
 import org.springframework.data.jpa.repository.sample.SampleEvaluationContextExtension.SampleSecurityContextHolder;
 import org.springframework.data.jpa.repository.sample.UserRepository;
 import org.springframework.data.jpa.repository.sample.UserRepository.NameOnly;
@@ -2979,6 +2980,19 @@ void supportsInterfaceProjectionsWithNativeQueries() {
 		assertThat(result.getLastname()).isEqualTo(user.getLastname());
 	}
 
+	@Test // GH-2757
+	void supportsRecordsWithNativeQueries() {
+
+		flushTestUsers();
+
+		User user = repository.findAll().get(0);
+
+		NameOnlyRecord result = repository.findRecordProjectionByNativeQuery(user.getId());
+
+		assertThat(result.firstname()).isEqualTo(user.getFirstname());
+		assertThat(result.lastname()).isEqualTo(user.getLastname());
+	}
+
 	@Test // DATAJPA-1248
 	void supportsProjectionsWithNativeQueriesAndCamelCaseProperty() {
 

spring-data-jpa/src/test/java/org/springframework/data/jpa/repository/sample/NameOnlyRecord.java

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2018-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.jpa.repository.sample;
+
+public record NameOnlyRecord(String firstname, String lastname) {
+
+}

spring-data-jpa/src/test/java/org/springframework/data/jpa/repository/sample/UserRepository.java

@@ -558,6 +558,9 @@ List<User> findUsersByFirstnameForSpELExpressionWithParameterIndexOnlyWithEntity
 	@Query(value = "SELECT firstname, lastname FROM SD_User WHERE id = ?1", nativeQuery = true)
 	NameOnly findByNativeQuery(Integer id);
 
+	@NativeQuery("SELECT firstname, lastname FROM SD_User WHERE id = ?1")
+	NameOnlyRecord findRecordProjectionByNativeQuery(Integer id);
+
 	// GH-3155
 	@NativeQuery(value = "SELECT emailaddress, secondary_email_address FROM SD_User WHERE id = ?1",
 			sqlResultSetMapping = "emailDto")