DATACOUCH-237 - Prevent groupby on generated count queries

Fixes #119

src/main/java/org/springframework/data/couchbase/repository/query/N1qlCountQueryCreator.java

@@ -0,0 +1,125 @@
+/*
+ * Copyright 2012-2016 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
+ *
+ *        http://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.repository.query;
+
+import java.util.Iterator;
+
+import org.springframework.data.couchbase.core.convert.CouchbaseConverter;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.domain.Sort;
+import org.springframework.data.repository.query.ParameterAccessor;
+import org.springframework.data.repository.query.parser.PartTree;
+
+import com.couchbase.client.java.query.dsl.Expression;
+import com.couchbase.client.java.query.dsl.path.LimitPath;
+import com.couchbase.client.java.query.dsl.path.WherePath;
+
+/**
+ * 
+ * @author Mark Ramach
+ *
+ */
+public class N1qlCountQueryCreator extends N1qlQueryCreator {
+
+	public N1qlCountQueryCreator(PartTree tree, ParameterAccessor parameters, WherePath selectFrom,
+			CouchbaseConverter converter, CouchbaseQueryMethod queryMethod) {
+		super(tree, new CountParameterAccessor(parameters), selectFrom, converter, queryMethod);
+	}
+
+	@Override
+	protected LimitPath complete(Expression criteria, Sort sort) {
+		// Sorting is not allowed on aggregate count queries.
+		return super.complete(criteria, null);
+	}
+
+	private static class CountParameterAccessor implements ParameterAccessor {
+
+		private ParameterAccessor delegate;
+
+		public CountParameterAccessor(ParameterAccessor delegate) {
+			this.delegate = delegate;
+		}
+
+		public Pageable getPageable() {
+			return delegate.getPageable() != null ? new CountPageable(delegate.getPageable()) : null;
+		}
+
+		public Sort getSort() {
+			return null;
+		}
+
+		public Class<?> getDynamicProjection() {
+			return delegate.getDynamicProjection();
+		}
+
+		public Object getBindableValue(int index) {
+			return delegate.getBindableValue(index);
+		}
+
+		public boolean hasBindableNullValue() {
+			return delegate.hasBindableNullValue();
+		}
+
+		public Iterator<Object> iterator() {
+			return delegate.iterator();
+		}
+
+	}
+
+	private static class CountPageable implements Pageable {
+
+		private Pageable delegate;
+
+		public CountPageable(Pageable delegate) {
+			this.delegate = delegate;
+		}
+
+		public int getPageNumber() {
+			return delegate.getPageNumber();
+		}
+
+		public int getPageSize() {
+			return delegate.getPageSize();
+		}
+
+		public int getOffset() {
+			return delegate.getOffset();
+		}
+
+		public Sort getSort() {
+		  // Sorting is not allowed on aggregate count queries.
+			return null;
+		}
+
+		public Pageable next() {
+			return delegate.next();
+		}
+
+		public Pageable previousOrFirst() {
+			return delegate.previousOrFirst();
+		}
+
+		public Pageable first() {
+			return delegate.first();
+		}
+
+		public boolean hasPrevious() {
+			return delegate.hasPrevious();
+		}
+
+	}
+
+}

src/main/java/org/springframework/data/couchbase/repository/query/PartTreeN1qlBasedQuery.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2015 the original author or authors
+ * Copyright 2012-2016 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.
@@ -58,7 +58,7 @@ public class PartTreeN1qlBasedQuery extends AbstractN1qlBasedQuery {
     Expression bucket = i(getCouchbaseOperations().getCouchbaseBucket().name());
     WherePath countFrom = select(count("*").as(CountFragment.COUNT_ALIAS)).from(bucket);
 
-    N1qlQueryCreator queryCreator = new N1qlQueryCreator(partTree, accessor, countFrom,
+    N1qlQueryCreator queryCreator = new N1qlCountQueryCreator(partTree, accessor, countFrom,
         getCouchbaseOperations().getConverter(), getQueryMethod());
     return queryCreator.createQuery();
   }