Loading a Null value into an int variable

[aboon]

I am loading values from a database record into a class. One of the class properties is an int, which corresponds to an int fiel in the database.
However, sometimes the DB value in null, which causes an exception when assigning the value to the class property.

What is the standard proceure for dealing with this problem?

Thanks

[balabaster]

Check to make sure that value is not null first...

[aboon]

Hi balabaster,

What if I can not change the value in the database to not null. This is how it works...

Employee enters start dates and en dates. If the employee is currently employed, then he only needs to enter start date, and the end date will be null and the null value is stored in the DB.

I'm trying to get the value of start dates and end dates to calculate the working period.When it comes to the record of currently working which the date end is null. I want to set the null value from the DB to int value. Is there the way to do that?

thanks

[balabaster]

Hi balabaster,

What if I can not change the value in the database to not null. This is how it works...

Employee enters start dates and en dates. If the employee is currently employed, then he only needs to enter start date, and the end date will be null and the null value is stored in the DB.

I'm trying to get the value of start dates and end dates to calculate the working period.When it comes to the record of currently working which the date end is null. I want to set the null value from the DB to int value. Is there the way to do that?

thanks

The point of null is there's nothing there... null = empty = nothing = void. You can't change nothing to an integer, there's nothing to change it's like trying to produce a rabbit out of thin air... If you wish to display values that do exist, and don't display values that don't exist then you have to check and see if the data in the database is null, and if it's not null, then display it as an integer...

if (value != null) textbox1.text = value;

and the other way:

if (textbox1.text = "") dbvalue = null;

[artov]

NULL in databases in one (I guess main) reason there is Nullable<T> structure
in .NET. In C# it is marked with ?, so in your case:

clas MyClass
{
int? theValue;
..
}

If (dbValue.IsNull )
myObject.theVal ue = null;
else
myObject.theVal ue = dbValue.Value;

So, Nullable<T> works like T, but there is an value null (quite like the value
in SQL, where there is also NULL).

[MrMancunian]

You didn't supply us with the language you're using, so here's the VB-equivalent:

Dim intValue as Integer
If Not IsDBNull(<databasevalue>) Then
  intValue = <databasevalue>
Else
  intValue = 0
End If

[aboon]

thank you all of you. I'll try your advice. I'm using C#. sorry I didn't provide the language I'm using at first place.