Do not override existing limit in R2dbcEntityTemplate.selectOne.

Closes #758

Author: RobertHeim

src/main/java/org/springframework/data/r2dbc/core/R2dbcEntityTemplate.java

@@ -91,6 +91,7 @@
  * @author Bogdan Ilchyshyn
  * @author Jens Schauder
  * @author Jose Luis Leon
+ * @author Robert Heim
  * @since 1.1
  */
 public class R2dbcEntityTemplate implements R2dbcEntityOperations, BeanFactoryAware, ApplicationContextAware {
@@ -448,7 +449,8 @@ private <T> RowsFetchSpec<T> doSelect(Query query, Class<?> entityClass, SqlIden
 	 */
 	@Override
 	public <T> Mono<T> selectOne(Query query, Class<T> entityClass) throws DataAccessException {
-		return doSelect(query.limit(2), entityClass, getTableName(entityClass), entityClass, RowsFetchSpec::one);
+		return doSelect(query.getLimit() != -1 ? query : query.limit(2), entityClass, getTableName(entityClass),
+				entityClass, RowsFetchSpec::one);
 	}
 
 	/*
@@ -641,11 +643,9 @@ private <T> Mono<T> doInsert(T entity, SqlIdentifier tableName, OutboundRow outb
 					}
 
 					return statement.returnGeneratedValues(dataAccessStrategy.renderForGeneratedValues(identifierColumns.get(0)));
-				})
-				.map(this.dataAccessStrategy.getConverter().populateIdIfNecessary(entity)) //
+				}).map(this.dataAccessStrategy.getConverter().populateIdIfNecessary(entity)) //
 				.all() //
-				.last(entity)
-				.flatMap(saved -> maybeCallAfterSave(saved, outboundRow, tableName));
+				.last(entity).flatMap(saved -> maybeCallAfterSave(saved, outboundRow, tableName));
 	}
 
 	@SuppressWarnings("unchecked")

src/test/java/org/springframework/data/r2dbc/core/R2dbcEntityTemplateUnitTests.java

@@ -67,6 +67,7 @@
  *
  * @author Mark Paluch
  * @author Jose Luis Leon
+ * @author Robert Heim
  */
 public class R2dbcEntityTemplateUnitTests {
 
@@ -200,6 +201,23 @@ void shouldSelectOne() {
 		assertThat(statement.getBindings()).hasSize(1).containsEntry(0, Parameter.from("Walter"));
 	}
 
+	@Test // gh-758
+	void shouldSelectOneDoNotOverrideExistingLimit() {
+
+		recorder.addStubbing(s -> s.startsWith("SELECT"), Collections.emptyList());
+
+		entityTemplate
+				.selectOne(Query.query(Criteria.where("name").is("Walter")).sort(Sort.by("name")).limit(1), Person.class) //
+				.as(StepVerifier::create) //
+				.verifyComplete();
+
+		StatementRecorder.RecordedStatement statement = recorder.getCreatedStatement(s -> s.startsWith("SELECT"));
+
+		assertThat(statement.getSql())
+				.isEqualTo("SELECT person.* FROM person WHERE person.THE_NAME = $1 ORDER BY person.THE_NAME ASC LIMIT 1");
+		assertThat(statement.getBindings()).hasSize(1).containsEntry(0, Parameter.from("Walter"));
+	}
+
 	@Test // gh-220
 	void shouldUpdateByQuery() {