Calling a stored procedure with null parameters and SqlDataAdapter

I have a stored procedure which I cann from my C# code. I am passing some parameters which I put in a HashTable first. It looks like that:

paramname1 value1

paramname2 value2

para开发者_StackOverflowmname3 value3

Any of the values can be null. So now I am going through that hash and add the params to the adapter:

foreach (DictionaryEntry entry in myHash)
{
    adapter.SelectCommand.Parameters.AddWithValue(entry.Key.ToString(), entry.Value);
}

This works, but when I try to fill a DataSet, it fails:

DataSet reportDataSet = new DataSet();
adapter.Fill(reportDataSet);

The error message is that it complains about a missing procedure parameter. Ideas?

Thanks :-)

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I think you have to check if its null and set it to DBNull.Value instead of null otherwise it thinks that the parameter is missing as it has a null value.