added DataStore.addTime()

DataStore.py

@@ -127,3 +127,30 @@ VALUES (?, ?, ?, ?)
         c.close()
         self.conn.commit()
         return nextid
+
+    def addTime(self, date, taskid, seconds):
+        c = self.conn.cursor()
+        exists = False
+        oldseconds = 0
+        c.execute('''
+SELECT seconds
+FROM entries
+WHERE date = ? AND taskid = ?
+''', (date, taskid))
+        for row in c:
+            if row[0] is not None:
+                exists = True
+                oldseconds = row[0]
+        if exists:
+            c.execute('''
+UPDATE entries
+SET seconds = ?
+WHERE date = ? AND taskid = ?
+''', (oldseconds + seconds, date, taskid))
+        else:
+            c.execute('''
+INSERT INTO entries
+VALUES(?, ?, ?)
+''', (date, taskid, seconds))
+        c.close()
+        self.conn.commit()