Sql-server – NHibernate won’t persist DateTime SqlDateTime overflow


I am working on an ASP.NET MVC project with NHibernate as the backend and am having some trouble getting some dates to write back to my SQL Server database tables.

These date fields are NOT nullable, so the many answers here about how to setup nullable datetimes have not helped.

Basically when I try to save the entity which has a DateAdded and a LastUpdated fields, I am getting a SqlDateTime overflow exception. I have had a similar problem in the past where I was trying to write a datetime field into a smalldatetime column, updating the type on the column appeared to fix the problem. My gut feeling is that its going to be some problem with the table definition or some type of incompatible data types, and the overflow exception is a bit of a bum steer.

I have attached an example of the table definition and the query that NHibernate is trying to run, any help or suggestions would be greatly appreciated.

CREATE TABLE [dbo].[CustomPages](
    [ID] [uniqueidentifier] NOT NULL,
    [StoreID] [uniqueidentifier] NOT NULL,
    [DateAdded] [datetime] NOT NULL,
    [AddedByID] [uniqueidentifier] NOT NULL,
    [LastUpdated] [datetime] NOT NULL,
    [LastUpdatedByID] [uniqueidentifier] NOT NULL,
    [Title] [nvarchar](150) NOT NULL,
    [Term] [nvarchar](150) NOT NULL,
    [Content] [ntext] NULL

exec sp_executesql N'INSERT INTO CustomPages (Title, Term, Content, LastUpdated, DateAdded, StoreID, LastUpdatedById, AddedById, ID) VALUES (@p0, @p1, @p2, @p3, @p4, @p5, @p6, @p7, @p8)',N'@p0 
nvarchar(21),@p1 nvarchar(21),@p2 nvarchar(33),@p3 datetime,@p4 datetime,@p5 uniqueidentifier,@p6 uniqueidentifier,@p7 uniqueidentifier,@p8 uniqueidentifier',@p0=N'Size and Colour 
Chart',@p1=N'size-and-colour-chart',@p2=N'This is the size and colour chart',@p3=''2009-03-14 14:29:37:000'',@p4=''2009-03-14 

In response the the answers/comments, I am using Fluent NHibernate and the generated mapping is below

  public CustomPageMap() {


            Id( x => x.ID, "ID" )
            .   GeneratedBy.Guid();

            References(x => x.Store, "StoreID");

            Map(x => x.DateAdded, "DateAdded");
            References(x => x.AddedBy, "AddedById");
            Map(x => x.LastUpdated, "LastUpdated");
            References(x => x.LastUpdatedBy, "LastUpdatedById");

            Map(x => x.Title, "Title");
            Map(x => x.Term, "Term");
            Map(x => x.Content, "Content");


    <?xml version="1.0" encoding="utf-8"?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" default-lazy="false" assembly="MyNamespace.Core" namespace="MyNamespace.Core">
<class name="CustomPage" table="CustomPages" xmlns="urn:nhibernate-mapping-2.2">
<id name="ID" column="ID" type="Guid" unsaved-value="00000000-0000-0000-0000-000000000000"><generator class="guid" /></id>
<property name="Title" column="Title" length="100" type="String"><column name="Title" /></property>
<property name="Term" column="Term" length="100" type="String"><column name="Term" /></property>
<property name="Content" column="Content" length="100" type="String"><column name="Content" /></property>
<property name="LastUpdated" column="LastUpdated" type="DateTime"><column name="LastUpdated" /></property>
<property name="DateAdded" column="DateAdded" type="DateTime"><column name="DateAdded" /></property>
<many-to-one name="Store" column="StoreID" /><many-to-one name="LastUpdatedBy" column="LastUpdatedById" />
<many-to-one name="AddedBy" column="AddedById" /></class></hibernate-mapping>

Best Solution

Actually the reason behind the scene is:

When NHibernate reads the row from the db, the value is null, and that is what the session remembers. When the object is rehydrated by NHibernate the Date is set to the value DateTime.MinValue. When the Session is synchronized with the db, NHibernate assumes that something has changed, because the currentState and the previousState are different and tries to update the row. Which in turn fails, because DateTime.MinValue will not fit into a SqlServer datetime column.

The solution: make your datetime nullable either by putting ? at end of Datetime like DateTime? or Nullable

complet article can be found at: nhibernate-sqldatetime-overflow-issue