Restore projection of class.

src/main/java/org/springframework/data/couchbase/repository/query/StringBasedN1qlQueryParser.java

@@ -162,11 +162,12 @@ public N1qlSpelValues createN1qlSpelValues(String bucketName, String collection,
 		String b = collection != null ? collection : bucketName;
 		Assert.isTrue(!(distinctFields != null && fields != null),
 				"only one of project(fields) and distinct(distinctFields) can be specified");
-		String entity = "META(" + i(b) + ").id AS " + SELECT_ID + ", META(" + i(b) + ").cas AS " + SELECT_CAS;
+		String entity = "META(" + i(b) + ").id AS " + SELECT_ID + ", META(" + i(b) + ").cas AS " + SELECT_CAS + ", "
+				+ i(typeField);
 		String count = "COUNT(*) AS " + CountFragment.COUNT_ALIAS;
 		String selectEntity;
 		if (distinctFields != null) {
-			String distinctFieldsStr = getProjectedOrDistinctFields(b, domainClass, fields, distinctFields);
+			String distinctFieldsStr = getProjectedOrDistinctFields(b, domainClass, typeField, fields, distinctFields);
 			if (isCount) {
 				selectEntity = "SELECT COUNT( DISTINCT {" + distinctFieldsStr + "} ) " + CountFragment.COUNT_ALIAS + " FROM "
 						+ i(b);
@@ -176,7 +177,7 @@ public N1qlSpelValues createN1qlSpelValues(String bucketName, String collection,
 		} else if (isCount) {
 			selectEntity = "SELECT " + count + " FROM " + i(b);
 		} else {
-			String projectedFields = getProjectedOrDistinctFields(b, domainClass, fields, distinctFields);
+			String projectedFields = getProjectedOrDistinctFields(b, domainClass, typeField, fields, distinctFields);
 			selectEntity = "SELECT " + entity + (!projectedFields.isEmpty() ? ", " : " ") + projectedFields + " FROM " + i(b);
 		}
 		String typeSelection = "`" + typeField + "` = \"" + typeValue + "\"";
@@ -187,22 +188,22 @@ public N1qlSpelValues createN1qlSpelValues(String bucketName, String collection,
 		return new N1qlSpelValues(selectEntity, entity, i(b).toString(), typeSelection, delete, returning);
 	}
 
-	private String getProjectedOrDistinctFields(String b, Class resultClass, String[] fields, String[] distinctFields) {
+	private String getProjectedOrDistinctFields(String b, Class resultClass, String typeField, String[] fields, String[] distinctFields) {
 		if (distinctFields != null && distinctFields.length != 0) {
 			return i(distinctFields).toString();
 		}
 		String projectedFields = i(b) + ".*";
 		if (resultClass != null) {
 			PersistentEntity persistentEntity = couchbaseConverter.getMappingContext().getPersistentEntity(resultClass);
 			StringBuilder sb = new StringBuilder();
-			getProjectedFieldsInternal(b, null, sb, persistentEntity, fields, distinctFields != null);
+			getProjectedFieldsInternal(b, null, sb, persistentEntity, typeField, fields, distinctFields != null);
 			projectedFields = sb.toString();
 		}
 		return projectedFields;
 	}
 
 	private void getProjectedFieldsInternal(String bucketName, CouchbasePersistentProperty parent, StringBuilder sb,
-			PersistentEntity persistentEntity, String[] fields, boolean forDistinct) {
+			PersistentEntity persistentEntity, String typeField, String[] fields, boolean forDistinct) {
 
 		if (persistentEntity != null) {
 			Set<String> fieldList = fields != null ? new HashSet<>(Arrays.asList(fields)) : null;
@@ -216,6 +217,8 @@ private void getProjectedFieldsInternal(String bucketName, CouchbasePersistentPr
 				if (prop == persistentEntity.getVersionProperty() && parent == null) {
 					return;
 				}
+				if( prop.getFieldName().equals(typeField)) // typeField already projected
+					return;
 				// for distinct when no distinctFields were provided, do not include the expiration field.
 				if (forDistinct && prop.findAnnotation(Expiration.class) != null && parent == null) {
 					return;
@@ -253,8 +256,10 @@ private void getProjectedFieldsInternal(String bucketName, CouchbasePersistentPr
 			}
 		} else {
 			for (String field : fields) {
-				if (sb.length() > 0) {
-					sb.append(", ");
+				if (!field.equals(typeField)) { // typeField is already projected
+					if (sb.length() > 0) {
+						sb.append(", ");
+					}
 				}
 				sb.append(x(field));
 			}

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

@@ -0,0 +1,105 @@
+/*
+ * Copyright 2012-2020 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.couchbase.domain;
+
+import java.util.Objects;
+
+import org.springframework.data.annotation.CreatedBy;
+import org.springframework.data.annotation.CreatedDate;
+import org.springframework.data.annotation.Id;
+import org.springframework.data.annotation.LastModifiedBy;
+import org.springframework.data.annotation.LastModifiedDate;
+import org.springframework.data.annotation.PersistenceConstructor;
+import org.springframework.data.annotation.Transient;
+import org.springframework.data.annotation.Version;
+import org.springframework.data.couchbase.core.mapping.Document;
+
+/**
+ * User entity for tests
+ *
+ * @author Michael Reiche
+ */
+
+public abstract class AbstractUser extends ComparableEntity {
+
+	@Version protected long version;
+	@Id protected String id;
+	protected String firstname;
+	protected String lastname;
+	@Transient protected String transientInfo;
+	@CreatedBy protected String createdBy;
+	@CreatedDate protected long createdDate;
+	@LastModifiedBy protected String lastModifiedBy;
+	@LastModifiedDate protected long lastModifiedDate;
+
+	public String getId() {
+		return id;
+	}
+
+	public String getFirstname() {
+		return firstname;
+	}
+
+	public String getLastname() {
+		return lastname;
+	}
+
+	public long getCreatedDate() {
+		return createdDate;
+	}
+
+	public void setCreatedDate(long createdDate) {
+		this.createdDate = createdDate;
+	}
+
+	public String getCreatedBy() {
+		return createdBy;
+	}
+
+	public void setCreatedBy(String createdBy) {
+		this.createdBy = createdBy;
+	}
+
+	public long getLastModifiedDate() {
+		return lastModifiedDate;
+	}
+
+	public String getLastModifiedBy() {
+		return lastModifiedBy;
+	}
+
+	public long getVersion() {
+		return version;
+	}
+
+	public void setVersion(long version) {
+		this.version = version;
+	}
+
+	@Override
+	public int hashCode() {
+		return Objects.hash(getId(), firstname, lastname);
+	}
+
+	public String getTransientInfo() {
+		return transientInfo;
+	}
+
+	public void setTransientInfo(String something) {
+		transientInfo = something;
+	}
+}

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

@@ -0,0 +1,63 @@
+/*
+ * Copyright 2012-2021 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.couchbase.domain;
+
+import java.util.List;
+import java.util.stream.Stream;
+
+import com.couchbase.client.java.query.QueryScanConsistency;
+import org.springframework.data.couchbase.repository.CouchbaseRepository;
+import org.springframework.data.couchbase.repository.Query;
+import org.springframework.data.couchbase.repository.ScanConsistency;
+import org.springframework.data.repository.query.Param;
+import org.springframework.stereotype.Repository;
+
+import com.couchbase.client.java.json.JsonArray;
+
+/**
+ * AbstractUser Repository for tests
+ * 
+ * @author Michael Reiche
+ */
+@Repository
+@ScanConsistency(query=QueryScanConsistency.REQUEST_PLUS)
+public interface AbstractUserRepository extends CouchbaseRepository<AbstractUser, String> {
+
+	@Query("#{#n1ql.selectEntity} where (meta().id = $1)")
+	AbstractUser myFindById(String id);
+
+	List<User> findByFirstname(String firstname);
+
+	Stream<User> findByLastname(String lastname);
+
+	List<User> findByFirstnameIn(String... firstnames);
+
+	List<User> findByFirstnameIn(JsonArray firstnames);
+
+	List<User> findByFirstnameAndLastname(String firstname, String lastname);
+
+	@Query("#{#n1ql.selectEntity} where #{#n1ql.filter} and firstname = $1 and lastname = $2")
+	List<User> getByFirstnameAndLastname(String firstname, String lastname);
+
+	@Query("#{#n1ql.selectEntity} where #{#n1ql.filter} and (firstname = $first or lastname = $last)")
+	List<User> getByFirstnameOrLastname(@Param("first") String firstname, @Param("last") String lastname);
+
+	List<User> findByIdIsNotNullAndFirstnameEquals(String firstname);
+
+	List<User> findByVersionEqualsAndFirstnameEquals(Long version, String firstname);
+
+}

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

@@ -35,7 +35,7 @@
 @Document
 @TypeAlias("airport")
 public class Airport extends ComparableEntity {
-	@Id String id;
+	@Id String key;
 
 	String iata;
 
@@ -49,14 +49,14 @@ public class Airport extends ComparableEntity {
 	long size;
 
 	@PersistenceConstructor
-	public Airport(String id, String iata, String icao) {
-		this.id = id;
+	public Airport(String key, String iata, String icao) {
+		this.key = key;
 		this.iata = iata;
 		this.icao = icao;
 	}
 
 	public String getId() {
-		return id;
+		return key;
 	}
 
 	public String getIata() {

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

@@ -174,6 +174,9 @@ Long countFancyExpression(@Param("projectIds") List<String> projectIds, @Param("
 			+ " #{#planIds != null ? 'AND blahblah IN $2' : ''} " + " #{#active != null ? 'AND false = $3' : ''} ")
 	Long countOne();
 
+	@ScanConsistency(query = QueryScanConsistency.REQUEST_PLUS)
+	Airport findByKey(String id);
+
 	@Retention(RetentionPolicy.RUNTIME)
 	@Target({ ElementType.METHOD, ElementType.TYPE })
 	// @Meta

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

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2022 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.couchbase.domain;
+
+import org.springframework.data.annotation.PersistenceConstructor;
+import org.springframework.data.couchbase.core.mapping.Document;
+
+/**
+ * OtherUser entity for tests. Both User and OtherUser extend AbstractUser
+ *
+ * @author Michael Reiche
+ */
+
+@Document
+public class OtherUser extends AbstractUser {
+
+	@PersistenceConstructor
+	public OtherUser(final String id, final String firstname, final String lastname) {
+		this.id = id;
+		this.firstname = firstname;
+		this.lastname = lastname;
+	}
+
+}