StuffHappens StuffHappens - 5 days ago 5
C# Question

Ado.net - the Size property has an invalid size of 0

I'm trying to get output value from DB via ADO.net. There's a client code:

using (var connection = new SqlConnection(ConnectionString))
{
connection.Open();
SqlCommand command = new SqlCommand("pDoSomethingParamsRes", connection);
command.CommandType = CommandType.StoredProcedure;
command.Parameters.Add("@i", 1);
var outParam = new SqlParameter("@out", SqlDbType.VarChar);
outParam.Direction = ParameterDirection.Output;
command.Parameters.Add(outParam);
command.ExecuteNonQuery();
Console.WriteLine(command.Parameters["@out"].Value.ToString());
}


When I run this I get the following exception:

the Size property has an invalid size of 0


According to manual SqlParameter.Size Property I might omit size. Why do I get this exception?
How to make it work without passing size?

Thank you for your help!

Answer

VarChar and NVarChar are variable width character fields (thus var+char). You have to set the length, otherwise the default is zero.

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