--- a/backend/src/main/java/org/dive4elements/river/model/sinfo/DailyDischargeValue.java	Wed Aug 15 13:59:09 2018 +0200
+++ b/backend/src/main/java/org/dive4elements/river/model/sinfo/DailyDischargeValue.java	Wed Aug 15 14:34:23 2018 +0200
@@ -11,7 +11,6 @@
 package org.dive4elements.river.model.sinfo;
 
 import java.io.Serializable;
-import java.util.ArrayList;
 import java.util.Date;
 import java.util.List;
 
@@ -50,6 +49,10 @@
         DAY, DISCHARGE;
     }
 
+    public enum MinMax {
+        min, max
+    }
+
     /***** FIELDS *****/
 
     private static final long serialVersionUID = -6192738825193230784L;
@@ -139,22 +142,17 @@
     /**
      * Selects from the database the daily discharge, puts the first and the last into a List (min, max day)
      */
-    public static List<DailyDischargeValue> getGlobalMinMax(final Gauge gauge) {
+
+    public static Date getGlobalMinMax(final Gauge gauge, final MinMax minmax) {
         final Session session = SessionHolder.HOLDER.get();
-        final Query query = session
-                .createQuery("SELECT v" + " FROM DailyDischargeValue AS v JOIN v.dailyDischarge AS s" + " WHERE (s.gauge.id=:gaugeid)  ORDER BY day");
+        final Query query = session.createQuery(
+                "SELECT " + minmax.toString() + "(v.day) " + " FROM DailyDischargeValue AS v JOIN v.dailyDischarge AS s" + " WHERE (s.gauge.id=:gaugeid)");
         query.setParameter("gaugeid", gauge.getId());
-        return minMaxFromDbResultHelper(query.list());
+        final List<Date> list = query.list();
+        if (list != null && list.size() == 1) {
+            return list.get(0);
+        }
+        return null;
     }
 
-    private static List<DailyDischargeValue> minMaxFromDbResultHelper(final List<DailyDischargeValue> values) {
-        if (values != null && values.size() > 1) {
-            final List<DailyDischargeValue> newList = new ArrayList<>();
-            newList.add(values.get(0));
-            newList.add(values.get(values.size() - 1));
-            return newList;
-        }
-        return null;
-
-    }
 }