Index: System.Data.SQLite/SQLiteDataReader.cs
==================================================================
--- System.Data.SQLite/SQLiteDataReader.cs
+++ System.Data.SQLite/SQLiteDataReader.cs
@@ -918,11 +918,13 @@
             foreach (ColumnParent key in parentToColumns.Keys)
             {
                 if (key == null)
                     continue;
 
-                if (String.IsNullOrEmpty(key.TableName))
+                string tableName = key.TableName;
+
+                if (String.IsNullOrEmpty(tableName))
                     continue;
 
                 result++;
             }
         }