diff --git a/Src/Asp.Net/SqlSugar/Infrastructure/ContextMethods.cs b/Src/Asp.Net/SqlSugar/Infrastructure/ContextMethods.cs
index 5ec9a5a98..480feee40 100644
--- a/Src/Asp.Net/SqlSugar/Infrastructure/ContextMethods.cs
+++ b/Src/Asp.Net/SqlSugar/Infrastructure/ContextMethods.cs
@@ -439,7 +439,7 @@ namespace SqlSugar
         private Dictionary<string, object> DataReaderToList<T>(IDataReader reader, Type tType, List<PropertyInfo> classProperties, List<T> reval)
         {
             var readerValues = DataReaderToDictionary(reader, tType);
-            var mappingKeys = this.QueryBuilder.MappingKeys;
+            var mappingKeys = this.QueryBuilder?.MappingKeys;
             var result = new Dictionary<string, object>();
             foreach (var item in classProperties)
             {