From 922e39f61deb4732033734efee44f71582d1fa51 Mon Sep 17 00:00:00 2001
From: Klaus Basan <klaus.basan@klausbasan.de>
Date: Sat, 8 Jul 2017 20:32:11 +0200
Subject: [PATCH] Ref T104, utility function

---
 src/blackmisc/db/datastoreobjectlist.cpp | 14 ++++++++++++++
 src/blackmisc/db/datastoreobjectlist.h   |  3 +++
 2 files changed, 17 insertions(+)

diff --git a/src/blackmisc/db/datastoreobjectlist.cpp b/src/blackmisc/db/datastoreobjectlist.cpp
index d3ac892d0..93e6b4641 100644
--- a/src/blackmisc/db/datastoreobjectlist.cpp
+++ b/src/blackmisc/db/datastoreobjectlist.cpp
@@ -79,6 +79,20 @@ namespace BlackMisc
             return keys;
         }
 
+        template<class OBJ, class CONTAINER, typename KEYTYPE>
+        QString IDatastoreObjectList<OBJ, CONTAINER, KEYTYPE>::dbKeysAsStrings(const QString &separator) const
+        {
+            if (ITimestampObjectList<OBJ, CONTAINER>::container().isEmpty()) { return ""; }
+            const QSet<KEYTYPE> keys = IDatastoreObjectList<OBJ, CONTAINER, KEYTYPE>::toDbKeySet();
+            QString s;
+            for (const KEYTYPE &k : keys)
+            {
+                if (!s.isEmpty()) { s += separator; }
+                s = s.append(k); // append works with string and int
+            }
+            return s;
+        }
+
         template <class OBJ, class CONTAINER, typename KEYTYPE>
         KEYTYPE IDatastoreObjectList<OBJ, CONTAINER, KEYTYPE>::getMaxKey(bool *ok) const
         {
diff --git a/src/blackmisc/db/datastoreobjectlist.h b/src/blackmisc/db/datastoreobjectlist.h
index 32604f2da..ea71e5811 100644
--- a/src/blackmisc/db/datastoreobjectlist.h
+++ b/src/blackmisc/db/datastoreobjectlist.h
@@ -38,6 +38,9 @@ namespace BlackMisc
             //! All keys as list
             QSet<KEYTYPE> toDbKeySet() const;
 
+            //! The DB keys as string
+            QString dbKeysAsStrings(const QString &separator) const;
+
             //! Max.key value (making sense with integer key)
             KEYTYPE getMaxKey(bool *ok = nullptr) const;