diff --git a/Src/Asp.Net/SqlSugar/Abstract/SaveableProvider/Storageable.cs b/Src/Asp.Net/SqlSugar/Abstract/SaveableProvider/Storageable.cs
index 6fc5b1447..a63ba06c8 100644
--- a/Src/Asp.Net/SqlSugar/Abstract/SaveableProvider/Storageable.cs
+++ b/Src/Asp.Net/SqlSugar/Abstract/SaveableProvider/Storageable.cs
@@ -331,7 +331,7 @@ namespace SqlSugar
                         FieldName = item.DbColumnName,
                         ConditionalType = ConditionalType.Equal,
                         CSharpTypeName=UtilMethods.GetTypeName(value),
-                        FieldValue = value + "",
+                        FieldValue = value==null?"null":value.ObjToString(),
                         FieldValueConvertFunc=this.Context.CurrentConnectionConfig.DbType==DbType.PostgreSQL? 
                                                UtilMethods.GetTypeConvert(value):null
                     }));