[fix] Remove JOIN FETCH when using COUNT query (#68)

Previous versions of Spring still need this check.

Author: darrachequesne

src/main/java/org/springframework/data/jpa/datatables/SpecificationBuilder.java

@@ -27,6 +27,11 @@ private class DataTablesSpecification<S> implements Specification<S> {
  public Predicate toPredicate(Root<S> root, CriteriaQuery<?> query, CriteriaBuilder criteriaBuilder) {
  initPredicatesRecursively(tree, root, root, criteriaBuilder);
 
+ boolean isCountQuery = query.getResultType() == Long.class;
+ if (isCountQuery) {
+ root.getFetches().clear();
+ }
+
  return createFinalPredicate(criteriaBuilder);
  }