fix: switch off lower(COLUMN_NAME) decoration on String equality check

Author: igdianov

graphql-jpa-query-schema/src/main/java/com/introproventures/graphql/jpa/query/schema/impl/JpaPredicateBuilder.java

@@ -105,13 +105,12 @@ protected Predicate addOrNull(Path<?> root, Predicate p) {
      * @return
      */
     protected Predicate getStringPredicate(Path<String> root, PredicateFilter filter) {
-        Expression<String> fieldValue;
-
         // list or arrays only for in and not in, between and not between
         Predicate arrayValuePredicate = mayBeArrayValuePredicate(root, filter);
 
         if(arrayValuePredicate == null) {
             String compareValue = filter.getValue().toString();
+            Expression<String> fieldValue = root;
 
             if (filter.getCriterias().contains(PredicateFilter.Criteria.IN)) {
                 CriteriaBuilder.In<Object> in = cb.in(root);
@@ -120,14 +119,18 @@ protected Predicate getStringPredicate(Path<String> root, PredicateFilter filter
             if (filter.getCriterias().contains(PredicateFilter.Criteria.NIN)) {
                 return cb.not(root.in(compareValue));
             }
-
+            
             if (filter.getCriterias().contains(PredicateFilter.Criteria.CASE)) {
                 fieldValue = root;
             }
-            else {
+            else if (filter.getCriterias().contains(PredicateFilter.Criteria.LOWER)) {
                 fieldValue = cb.lower(root);
                 compareValue = compareValue.toLowerCase();
             }
+            else if (filter.getCriterias().contains(PredicateFilter.Criteria.UPPER)) {
+                fieldValue = cb.upper(root);
+                compareValue = compareValue.toUpperCase();
+            }
 
             if (filter.getCriterias().contains(PredicateFilter.Criteria.EQ)) {
                 return cb.equal(fieldValue, compareValue);

graphql-jpa-query-schema/src/main/java/com/introproventures/graphql/jpa/query/schema/impl/PredicateFilter.java

@@ -60,6 +60,14 @@ public enum Criteria {
          * case sensitive (strings)
          */
         CASE,
+        /**
+         * uppercase expression match (strings)
+         */
+        UPPER,
+        /**
+         * lowercase expression match (strings)
+         */
+        LOWER,
         /**
          * end of the string matches
          * <pre>LOWER(field) LIKE LOWER(SEARCH)</pre> if not set then case