For columns not defined as System.String, the only valid value is (Throw exception).

[Rob Dob]

I am trying to set the NullValue within the Column properties of my Dataset
in VS2005. The DataType is a System.DateTime. and when I try and change it
from "(Throw Exception)" I get the following error:

For columns not defined as System.String, the only valid value is (Throw
exception).

The Datafield is a datetime that allows nulls, if I don't set this value
then when I try save changes to this field within my form I get it
complaining about not allowing DBNull for that field..



I am also having this same problem with DataType int where I also allow
nulls



any help would be appreciated.,

 

[Steven Nagy]

Hi Rob,

First, can we see the code where you are assigning your null to your
datarow?
Secondly, is the dataset a 'typed' dataset?
And finally, what database are you using?

Cheers,
Steven

 

[Rob Dob]

Hi,

I have a DateTimePicker Databound to Dataset datacolumn whicc allow nulls:

And before I call update on my tableadapter I do something like: where ( ordersCustomersRow ) is a view of two combined tables.
ordersRow.Permit_Date = ordersCustomersRow.Permit_Date;

I'm using MSSQL2005

 

[Mel]

I set it using parameters, something like


using (SqlCommand cmd = new SqlCommand())
{
cmd.CommandText = "Update Policys set ExpDate = @ExpDate where
primaryKey = @primaryKey";
cmd.Parameters.Add("@ExpDate", SqlDbType.DateTime).Value = DBNull.Value;
cmd.Parameters.Add("@primaryKey", SqlDbType.Int).Value = 100;
}

 

[Rob Dob]

Hi,

I set it using parameters, something like


using (SqlCommand cmd = new SqlCommand())
{
cmd.CommandText = "Update Policys set ExpDate = @ExpDate where
primaryKey = @primaryKey";
cmd.Parameters.Add("@ExpDate", SqlDbType.DateTime).Value =
DBNull.Value;
cmd.Parameters.Add("@primaryKey", SqlDbType.Int).Value = 100;
}

I would prefer to just set the value within my strongly typed dataset before
I call its TableAdaptersUpdate(), is this possible?

Thanks,

 

[Bart Mermuys]

Hi,

I have a DateTimePicker Databound to Dataset datacolumn whicc allow nulls:

And before I call update on my tableadapter I do something like: where
( ordersCustomersRow ) is a view of two combined tables.

ordersRow.Permit_Date = ordersCustomersRow.Permit_Date;

Try something like:

if ( ordersCustomersRow.IsPermit_DateNull() )
odersRow.SetPermit_DateNull()
else
ordersRow.Permit_Date = ordersCustomersRow.Permit_Date

Or simply untyped:

ordersRow["Permit_Date"] = ordersCustomerRow["Permit_Date"];

HTH,
Greetings