DATAJPA-1163 - Evaluate expression "#{#entityName}" in count queries.

SpEL expressions based on the entityName are now supported in count queries.

Original pull request: #283.

src/main/java/org/springframework/data/jpa/repository/query/AbstractStringBasedJpaQuery.java

@@ -34,6 +34,7 @@ import org.springframework.util.Assert;
  * @author Oliver Gierke
  * @author Thomas Darimont
  * @author Jens Schauder
+ * @author Tom Hombergs
  */
 abstract class AbstractStringBasedJpaQuery extends AbstractJpaQuery {
 
@@ -63,7 +64,9 @@ abstract class AbstractStringBasedJpaQuery extends AbstractJpaQuery {
 
 		this.evaluationContextProvider = evaluationContextProvider;
 		this.query = new ExpressionBasedStringQuery(queryString, method.getEntityInformation(), parser);
-		this.countQuery = query.deriveCountQuery(method.getCountQuery(), method.getCountQueryProjection());
+
+		DeclaredQuery countQuery = query.deriveCountQuery(method.getCountQuery(), method.getCountQueryProjection());
+		this.countQuery = ExpressionBasedStringQuery.from(countQuery, method.getEntityInformation(), parser);
 
 		this.parser = parser;
 

src/main/java/org/springframework/data/jpa/repository/query/ExpressionBasedStringQuery.java

@@ -34,6 +34,7 @@ import org.springframework.util.Assert;
  *
  * @author Thomas Darimont
  * @author Oliver Gierke
+ * @author Tom Hombergs
  */
 class ExpressionBasedStringQuery extends StringQuery {
 
@@ -59,6 +60,19 @@ class ExpressionBasedStringQuery extends StringQuery {
 		super(renderQueryIfExpressionOrReturnQuery(query, metadata, parser));
 	}
 
+	/**
+	 * Creates an {@link ExpressionBasedStringQuery} from a given {@link DeclaredQuery}.
+	 * 
+	 * @param query the original query. Must not be {@literal null}.
+	 * @param metadata the {@link JpaEntityMetadata} for the given entity. Must not be {@literal null}.
+	 * @param parser Parser for resolving SpEL expressions. Must not be {@literal null}.
+	 * @return A query supporting SpEL expressions.
+	 */
+	public static ExpressionBasedStringQuery from(DeclaredQuery query, JpaEntityMetadata metadata,
+			SpelExpressionParser parser) {
+		return new ExpressionBasedStringQuery(query.getQueryString(), metadata, parser);
+	}
+
 	/**
 	 * @param query, the query expression potentially containing a SpEL expression. Must not be {@literal null}.}
 	 * @param metadata the {@link JpaEntityMetadata} for the given entity. Must not be {@literal null}.

src/test/java/org/springframework/data/jpa/repository/query/SimpleJpaQueryUnitTests.java

@@ -58,6 +58,7 @@ import org.springframework.expression.spel.standard.SpelExpressionParser;
  * @author Oliver Gierke
  * @author Thomas Darimont
  * @author Jens Schauder
+ * @author Tom Hombergs
  */
 @RunWith(MockitoJUnitRunner.Silent.class)
 public class SimpleJpaQueryUnitTests {
@@ -229,6 +230,22 @@ public class SimpleJpaQueryUnitTests {
 				.isThrownBy(() -> createJpaQuery(illegalMethod));
 	}
 
+	@Test // DATAJPA-1163
+	public void resolvesExpressionInCountQuery() throws Exception {
+
+		when(em.createQuery(Mockito.anyString())).thenReturn(query);
+
+		Method method = UserRepository.class.getMethod("findAllWithExpressionInCountQuery", Pageable.class);
+		JpaQueryMethod queryMethod = new JpaQueryMethod(method, metadata, factory, extractor);
+
+		AbstractJpaQuery jpaQuery = new SimpleJpaQuery(queryMethod, em, "select u from User u", EVALUATION_CONTEXT_PROVIDER,
+				PARSER);
+		jpaQuery.createCountQuery(new Object[] { PageRequest.of(1, 10) });
+
+		verify(em).createQuery(eq("select u from User u"));
+		verify(em).createQuery(eq("select count(u.id) from User u"), eq(Long.class));
+	}
+
 	private AbstractJpaQuery createJpaQuery(Method method) {
 
 		JpaQueryMethod queryMethod = new JpaQueryMethod(method, metadata, factory, extractor);

src/test/java/org/springframework/data/jpa/repository/sample/UserRepository.java

@@ -556,6 +556,10 @@ public interface UserRepository
 	// DATAJPA-1334
 	List<NameOnlyDto> findByNamedQueryWithConstructorExpression();
 
+	// DATAJPA-1163
+	@Query(value = "select u from #{#entityName} u", countQuery = "select count(u.id) from #{#entityName} u")
+	List<User> findAllWithExpressionInCountQuery(Pageable pageable);
+
 	interface RolesAndFirstname {
 
 		String getFirstname();