Specific message for string queries that do not project __id and __cas.

src/main/java/org/springframework/data/couchbase/core/ReactiveFindByAnalyticsOperationSupport.java

@@ -19,7 +19,9 @@
 import reactor.core.publisher.Mono;
 
 import org.springframework.data.couchbase.core.query.AnalyticsQuery;
+import org.springframework.data.couchbase.core.support.TemplateUtils;
 
+import com.couchbase.client.core.error.CouchbaseException;
 import com.couchbase.client.java.analytics.AnalyticsOptions;
 import com.couchbase.client.java.analytics.AnalyticsScanConsistency;
 import com.couchbase.client.java.analytics.ReactiveAnalyticsResult;
@@ -92,10 +94,22 @@ public Flux<T> all() {
 								return throwable;
 							}
 						}).flatMapMany(ReactiveAnalyticsResult::rowsAsObject).map(row -> {
-							String id = row.getString("__id");
-							long cas = row.getLong("__cas");
-							row.removeKey("__id");
-							row.removeKey("__cas");
+							String id = "";
+							long cas = 0;
+							if (row.getString(TemplateUtils.SELECT_ID) == null) {
+								throw new CouchbaseException("analytics query did not project " + TemplateUtils.SELECT_ID
+										+ ". Either use #{#n1ql.selectEntity} or project " + TemplateUtils.SELECT_ID + " and "
+										+ TemplateUtils.SELECT_CAS + " : " + statement);
+							}
+							id = row.getString(TemplateUtils.SELECT_ID);
+							if (row.getLong(TemplateUtils.SELECT_CAS) == null) {
+								throw new CouchbaseException("analytics query did not project " + TemplateUtils.SELECT_CAS
+										+ ". Either use #{#n1ql.selectEntity} or project " + TemplateUtils.SELECT_ID + " and "
+										+ TemplateUtils.SELECT_CAS + " : " + statement);
+							}
+							cas = row.getLong(TemplateUtils.SELECT_CAS);
+							row.removeKey(TemplateUtils.SELECT_ID);
+							row.removeKey(TemplateUtils.SELECT_CAS);
 							return template.support().decodeEntity(id, row.toString(), cas, domainType);
 						});
 			});

src/main/java/org/springframework/data/couchbase/core/ReactiveFindByQueryOperationSupport.java

@@ -22,6 +22,7 @@
 import org.springframework.data.couchbase.core.support.TemplateUtils;
 import org.springframework.util.Assert;
 
+import com.couchbase.client.core.error.CouchbaseException;
 import com.couchbase.client.java.query.QueryScanConsistency;
 import com.couchbase.client.java.query.ReactiveQueryResult;
 
@@ -147,7 +148,17 @@ public Flux<T> all() {
 					String id = "";
 					long cas = 0;
 					if (distinctFields == null) {
+						if (row.getString(TemplateUtils.SELECT_ID) == null) {
+							throw new CouchbaseException(
+									"query did not project " + TemplateUtils.SELECT_ID + ". Either use #{#n1ql.selectEntity} or project "
+											+ TemplateUtils.SELECT_ID + " and " + TemplateUtils.SELECT_CAS  + " : " + statement);
+						}
 						id = row.getString(TemplateUtils.SELECT_ID);
+						if (row.getLong(TemplateUtils.SELECT_CAS) == null) {
+							throw new CouchbaseException(
+									"query did not project " + TemplateUtils.SELECT_CAS + ". Either use #{#n1ql.selectEntity} or project "
+											+ TemplateUtils.SELECT_ID + " and " + TemplateUtils.SELECT_CAS + " : " + statement);
+						}
 						cas = row.getLong(TemplateUtils.SELECT_CAS);
 						row.removeKey(TemplateUtils.SELECT_ID);
 						row.removeKey(TemplateUtils.SELECT_CAS);

src/test/java/org/springframework/data/couchbase/domain/AirportRepository.java

@@ -57,6 +57,14 @@ public interface AirportRepository extends PagingAndSortingRepository<Airport, S
 	@ScanConsistency(query = QueryScanConsistency.REQUEST_PLUS)
 	List<Airport> getAllByIata(String iata);
 
+	@Query("SELECT __cas, * from `#{#n1ql.bucket}` where iata = $1")
+	@ScanConsistency(query = QueryScanConsistency.REQUEST_PLUS)
+	List<Airport> getAllByIataNoID(String iata);
+
+	@Query("SELECT __id, * from `#{#n1ql.bucket}` where iata = $1")
+	@ScanConsistency(query = QueryScanConsistency.REQUEST_PLUS)
+	List<Airport> getAllByIataNoCAS(String iata);
+
 	@ScanConsistency(query = QueryScanConsistency.REQUEST_PLUS)
 	long countByIataIn(String... iata);
 

src/test/java/org/springframework/data/couchbase/domain/Iata.java

@@ -1,6 +1,6 @@
 package org.springframework.data.couchbase.domain;
 
 public enum Iata {
-  vie,
+  vie, // must be lower-case to match "vie" as airport.iata is always specified in lowercase
   xxx
 }

src/test/java/org/springframework/data/couchbase/repository/CouchbaseRepositoryQueryIntegrationTests.java

@@ -20,6 +20,7 @@
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
@@ -34,7 +35,6 @@
 import java.util.concurrent.Future;
 import java.util.stream.Collectors;
 
-import com.couchbase.client.java.query.QueryScanConsistency;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -66,7 +66,9 @@
 import org.springframework.data.repository.core.support.DefaultRepositoryMetadata;
 import org.springframework.test.context.junit.jupiter.SpringJUnitConfig;
 
+import com.couchbase.client.core.error.CouchbaseException;
 import com.couchbase.client.core.error.IndexExistsException;
+import com.couchbase.client.java.query.QueryScanConsistency;
 
 /**
  * Repository tests
@@ -175,11 +177,13 @@ void findByEnum() {
 			vie = new Airport("airports::vie", "vie", "loww");
 			vie = airportRepository.save(vie);
 			Airport airport2 = airportRepository.findByIata(Iata.vie);
+			assertNotNull(airport2, "should have found "+vie);
 			assertEquals(airport2.getId(), vie.getId());
 		} finally {
 			airportRepository.delete(vie);
 		}
 	}
+
 	@Test
 	public void testCas() {
 		User user = new User("1", "Dave", "Wilson");
@@ -271,6 +275,19 @@ void threadSafeParametersTest() throws Exception {
 		}
 	}
 
+	@Test
+	void stringQueryTest() throws Exception {
+		Airport airport = new Airport("airports::vie", "vie", "lowx");
+		try {
+			airportRepository.save(airport);
+			airportRepository.getAllByIata("vie").get(0); // gets at least one with no exception
+			assertThrows(CouchbaseException.class, () -> airportRepository.getAllByIataNoID("vie"));
+			assertThrows(CouchbaseException.class, () -> airportRepository.getAllByIataNoCAS("vie"));
+		} finally {
+			airportRepository.deleteById(airport.getId());
+		}
+	}
+
 	@Test
 	void threadSafeStringParametersTest() throws Exception {
 		String[] iatas = { "JFK", "IAD", "SFO", "SJC", "SEA", "LAX", "PHX" };
@@ -332,14 +349,15 @@ void deleteAllById() {
 	void couchbaseRepositoryQuery() throws Exception {
 		User user = new User("1", "Dave", "Wilson");
 		userRepository.save(user);
-		couchbaseTemplate.findByQuery(User.class).withConsistency(QueryScanConsistency.REQUEST_PLUS).matching(QueryCriteria.where("firstname").is("Dave").and("`1`").is("`1`")).all();
+		couchbaseTemplate.findByQuery(User.class).withConsistency(QueryScanConsistency.REQUEST_PLUS)
+				.matching(QueryCriteria.where("firstname").is("Dave").and("`1`").is("`1`")).all();
 		String input = "findByFirstname";
 		Method method = UserRepository.class.getMethod(input, String.class);
 		CouchbaseQueryMethod queryMethod = new CouchbaseQueryMethod(method,
 				new DefaultRepositoryMetadata(UserRepository.class), new SpelAwareProxyProjectionFactory(),
 				couchbaseTemplate.getConverter().getMappingContext());
 		CouchbaseRepositoryQuery query = new CouchbaseRepositoryQuery(couchbaseTemplate, queryMethod, null);
-		List<User> users = (List<User>)query.execute(new String[] { "Dave" });
+		List<User> users = (List<User>) query.execute(new String[] { "Dave" });
 		assertEquals(user, users.get(0));
 	}