Removes PlainSelect casting in JSqlParserQueryEnhancer.

Closes: #3869
Original pull request: #3870

Signed-off-by: Diego Pedregal <[email protected]>

Author: thmasker

spring-data-jpa/src/test/java/org/springframework/data/jpa/repository/query/JSqlParserQueryEnhancerUnitTests.java

@@ -276,4 +276,13 @@ private static DefaultQueryRewriteInformation getRewriteInformation(Sort sort) {
 				ReturnedType.of(Object.class, Object.class, new SpelAwareProxyProjectionFactory()));
 	}
 
+	@Test // GH-3869
+	void shouldWorkWithoutFromClause() {
+		String query = "SELECT is_contained_in(:innerId, :outerId)";
+
+		StringQuery stringQuery = new StringQuery(query, true);
+
+		assertThat(stringQuery.getQueryString()).isEqualTo(query);
+	}
+
 }