Merge pull request #102 from youngpay/master

ThrowDataException is not Complete

Dapper NET40/SqlMapper.cs

@@ -2875,7 +2875,9 @@ public static void ThrowDataException(Exception ex, int index, IDataReader reade
                 if (reader != null && index >= 0 && index < reader.FieldCount)
                 {
                     name = reader.GetName(index);
-                    object val = reader.GetValue(index);
+                    try
+                    {
+                        object val = reader.GetValue(index); // if there throw an exception, then I got one message, but Which column?
                         if (val == null || val is DBNull)
                         {
                             value = "<null>";
@@ -2885,6 +2887,11 @@ public static void ThrowDataException(Exception ex, int index, IDataReader reade
                             value = Convert.ToString(val) + " - " + Type.GetTypeCode(val.GetType());
                         }
                     }
+                    catch (Exception valEx)
+                    {
+                        value = valEx.Message;
+                    }
+                }
                 toThrow = new DataException(string.Format("Error parsing column {0} ({1}={2})", index, name, value), ex);
             }
             catch