From bfb167c374f854b0a185ac749bfd0fb5aea5032a Mon Sep 17 00:00:00 2001
From: "kay.one" <kay.one@gmail.com>
Date: Thu, 11 Apr 2013 08:16:34 -0700
Subject: [PATCH] added check for marr data to throw a more meaning full
 exception when trying to operate on an unmapped column.

---
 Marr.Data/DataHelper.cs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Marr.Data/DataHelper.cs b/Marr.Data/DataHelper.cs
index 721511a2a..d5120894b 100644
--- a/Marr.Data/DataHelper.cs
+++ b/Marr.Data/DataHelper.cs
@@ -84,6 +84,12 @@ namespace Marr.Data
             string columnName = propertyName;
 
             var columnMap = MapRepository.Instance.GetColumns(declaringType).GetByFieldName(propertyName);
+
+            if (columnMap == null)
+            {
+                throw new InvalidOperationException(string.Format("Column map missing for field {0}.{1}", declaringType.FullName, propertyName));
+            }
+
             if (useAltName)
             {
                 columnName = columnMap.ColumnInfo.TryGetAltName();