diff --git a/rowers/dataprep.py b/rowers/dataprep.py
index 252e2bd9..b5712d7a 100644
--- a/rowers/dataprep.py
+++ b/rowers/dataprep.py
@@ -1905,7 +1905,10 @@ def testdata(time, distance, pace, spm):
 def getrowdata_db(id=0, doclean=False, convertnewtons=True,
                   checkefficiency=True):
     data = read_df_sql(id)
-    data['deltat'] = data['time'].diff()
+    try:
+        data['deltat'] = data['time'].diff()
+    except KeyError:
+        data = pd.DataFrame()
 
     if data.empty:
         rowdata, row = getrowdata(id=id)