DateType that can be: True, False or Null?

[DotNetNewbie]

Hi,

I need a datatype (or enum?) that can hold the possible values: true/
false/null

I will use it in ADO.NET code like:

sqlCmd.Parameters.Add("@isApproved", SqlDbType.Bit, 1).Value = ?????;

This way I can pass values of true,false or null to my stored
procedure.

Is there a way to do this or do I have to do things like :

if(myEnum != MyEnum.NULL)
sqlCmd.Parameters.Add("@isApproved", SqlDbType.Bit, 1).Value =
myEnum;

 

[Gilles Kohl [MVP]]

Hi,

I need a datatype (or enum?) that can hold the possible values: true/
false/null

Nullable types may be just what you're looking for:

http://msdn.microsoft.com/en-us/library/1t3y8s4s.aspx

Regards,
Gilles.

 

[Kalpesh]

????? = DBNull.Value

Does that work?

 

[qglyirnyfgfo]

Hi Gilles,

Ok, I confess, I am too lazy to try so I will ask… would this work
even if the sql parameter requires DBNull.Value?

Is passing null to an sql parameter equivalent to passing
DBNull.Value?

Thanks.

 

[Joachim Van den Bogaert]

With NUnit referenced, try this to find out whether DBNull and null
are the same (you will find they are not):

[TestFixture]
public class Test
{
[Test]
public void NullDBNullEqual()
{
Assert.AreEqual(null, DBNull.Value);
}
}

Joachim

 

[qglyirnyfgfo]

Thanks Joachim

I realize that DBNull.Value and null are not equal, that wasn’t the
question.

What I was interested in knowing is if the Value property of the SQL
parameter (SqlParameter) object will internally treat DBNull.Value and
null as being the same thing.

This is really no big deal, I was just curious.