diff --git a/rowers/dataprep.py b/rowers/dataprep.py
index 098285e3..eb3b6e8a 100644
--- a/rowers/dataprep.py
+++ b/rowers/dataprep.py
@@ -2559,7 +2559,10 @@ def read_cols_df_sql(ids, columns, convertnewtons=True):
                     df = pd.read_parquet(f,columns=columns)
                     data.append(df)
 
-        df = pd.concat(data,axis=0)
+        try:
+            df = pd.concat(data,axis=0)
+        except ValueError:
+            df = pd.DataFrame()
 
 
     df = df.fillna(value=0)