Question

In my data layer class, I initialize a parameter like so:

private int? _DependencyID;

public int? DependencyID
{ get {return _DependencyID;} set {_DependencyID = value;} }

public ConstructorMethod()
{
    _DependencyID = (int?)null;
}

In the class Insert() method, I am attempting

cmd.AddWithValue("@DependencyID", _DependencyID);

If _DependencyID has a value, all is well.
If _DependencyID is null, I get error:

The parameterized query
‘(@param1(nvarchar(10),
@param2(nvarchar(255), expects the
parameter ‘@DependecyID”, which was
not supplied

I found this [article][1], so I tried adjusting code like so:

cmd.AddWithValue("@DependencyID", _DependencyID == null? DBNull.Value : _DependencyID); 

                           and
cmd.AddWithValue("@DependencyID", _DependencyID == null? (int?) DBNull.Value : _DependencyID); 

Either way, there are issues. How should I handle this?

Thanks in advance for any help

Answer 1

You need to add an object:

cmd.AddWithValue("@DependencyID", _DependencyID == null? DBNull.Value : (object)_DependencyID); 

You can shorten that to

cmd.AddWithValue("@DependencyID", (object)_DependencyID ?? DBNull.Value);