c# – Object cannot be cast from DBNull to other types

c# – Object cannot be cast from DBNull to other types

Im thinking that your output parameter is coming back with a DBNull value. Add a check for that like this

var outputParam = dataAccCom.GetParameterValue(IDbCmd, op_Id);
if(!(outputParam is DBNull))
     DataTO.Id = Convert.ToInt64(outputParam);

I suspect that the line

DataTO.Id = Convert.ToInt64(dataAccCom.GetParameterValue(IDbCmd, op_Id));

is causing the problem. Is it possible that the op_Id value is being set to null by the stored procedure?

To Guard against it use the Convert.IsDBNull method. For example:

if (!Convert.IsDBNull(dataAccCom.GetParameterValue(IDbCmd, op_Id))
{
 DataTO.Id = Convert.ToInt64(dataAccCom.GetParameterValue(IDbCmd, op_Id));
}
else 
{
 DataTO.Id = ...some default value or perform some error case management
}

c# – Object cannot be cast from DBNull to other types

You need to check for DBNull, not null. Additionally, two of your three ReplaceNull methods dont make sense. double and DateTime are non-nullable, so checking them for null will always be false…