From f8450c61dfa24f1748986489790151b4deb31bf0 Mon Sep 17 00:00:00 2001
From: Oliver Gierke <ogierke@pivotal.io>
Date: Thu, 2 Jun 2016 12:37:36 +0200
Subject: [PATCH] DATAJPA-909 - Fixed count query execution for projections and
 pagination.

We now make sure that the count query for derived queries using pagination uses a plain count projection and does not try to apply that on a tuple query.
---
 .../query/JpaCountQueryCreator.java           | 10 ++++++++
 .../jpa/repository/query/JpaQueryCreator.java | 23 ++++++++++++-------
 2 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/src/main/java/org/springframework/data/jpa/repository/query/JpaCountQueryCreator.java b/src/main/java/org/springframework/data/jpa/repository/query/JpaCountQueryCreator.java
index ff111fc83..6eeb3eac3 100644
--- a/src/main/java/org/springframework/data/jpa/repository/query/JpaCountQueryCreator.java
+++ b/src/main/java/org/springframework/data/jpa/repository/query/JpaCountQueryCreator.java
@@ -45,11 +45,21 @@ public class JpaCountQueryCreator extends JpaQueryCreator {
 		super(tree, type, builder, provider);
 	}
 
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.jpa.repository.query.JpaQueryCreator#createCriteriaQuery(javax.persistence.criteria.CriteriaBuilder, org.springframework.data.repository.query.ReturnedType)
+	 */
+	@Override
+	protected CriteriaQuery<? extends Object> createCriteriaQuery(CriteriaBuilder builder, ReturnedType type) {
+		return builder.createQuery(type.getDomainType());
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.jpa.repository.query.JpaQueryCreator#complete(javax.persistence.criteria.Predicate, org.springframework.data.domain.Sort, javax.persistence.criteria.CriteriaQuery, javax.persistence.criteria.CriteriaBuilder, javax.persistence.criteria.Root)
 	 */
 	@Override
+	@SuppressWarnings({ "unchecked", "rawtypes" })
 	protected CriteriaQuery<? extends Object> complete(Predicate predicate, Sort sort,
 			CriteriaQuery<? extends Object> query, CriteriaBuilder builder, Root<?> root) {
 
diff --git a/src/main/java/org/springframework/data/jpa/repository/query/JpaQueryCreator.java b/src/main/java/org/springframework/data/jpa/repository/query/JpaQueryCreator.java
index f498040cc..e2ef5f5cb 100644
--- a/src/main/java/org/springframework/data/jpa/repository/query/JpaQueryCreator.java
+++ b/src/main/java/org/springframework/data/jpa/repository/query/JpaQueryCreator.java
@@ -67,10 +67,7 @@ public class JpaQueryCreator extends AbstractQueryCreator<CriteriaQuery<? extend
 
 		super(tree);
 
-		Class<?> typeToRead = type.getTypeToRead();
-
-		CriteriaQuery<? extends Object> criteriaQuery = typeToRead == null ? builder.createTupleQuery()
-				: builder.createQuery(typeToRead);
+		CriteriaQuery<? extends Object> criteriaQuery = createCriteriaQuery(builder, type);
 
 		this.builder = builder;
 		this.query = criteriaQuery.distinct(tree.isDistinct());
@@ -79,6 +76,20 @@ public class JpaQueryCreator extends AbstractQueryCreator<CriteriaQuery<? extend
 		this.returnedType = type;
 	}
 
+	/**
+	 * Creates the {@link CriteriaQuery} to apply predicates on.
+	 * 
+	 * @param builder will never be {@literal null}.
+	 * @param type will never be {@literal null}.
+	 * @return must not be {@literal null}.
+	 */
+	protected CriteriaQuery<? extends Object> createCriteriaQuery(CriteriaBuilder builder, ReturnedType type) {
+
+		Class<?> typeToRead = type.getTypeToRead();
+
+		return typeToRead == null ? builder.createTupleQuery() : builder.createQuery(typeToRead);
+	}
+
 	/**
 	 * Returns all {@link javax.persistence.criteria.ParameterExpression} created when creating the query.
 	 * 
@@ -169,10 +180,6 @@ public class JpaQueryCreator extends AbstractQueryCreator<CriteriaQuery<? extend
 		return new PredicateBuilder(part, root).build();
 	}
 
-	private <T> Expression<T> getTypedPath(Root<?> root, Part part) {
-		return toExpressionRecursively(root, part.getProperty());
-	}
-
 	/**
 	 * Simple builder to contain logic to create JPA {@link Predicate}s from {@link Part}s.
 	 *