I'm trying to determine how to specify null as a parameter value in an OracleCommand using the following C# code. I've excerpted the relevant bits, but basically the point is if sal_id comes in with the value 0 it should be stored as null. I've tried Null, "Null", and a couple other things but so far no luck.
cmd.CommandText = "INSERT INTO tcustomer(cust_id, salutation_id) VALUES(ORADBA.SEQCUST.NEXTVAL, :salid) RETURNING cust_id INTO :newcid" ;
if (sal_id==0) {
cmd.Parameters.Add("salid", Null) ;
} else {
cmd.Parameters.Add("salid", sal_id) ;
}
cmd.Parameters.Add("newcid", OracleDbType.Int32).Direction = ParameterDirection.ReturnValue ;
cmd.ExecuteNonQuery() ;
String newcidval = cmd.Parameters["newcid"].Value.ToString() ;
cmd.Dispose() ;
Try System.DBNull
insead of null
.
The DBNull class represents a nonexistent value. In a database, for example, a column in a row of a table might not contain any data whatsoever. That is, the column is considered to not exist at all instead of merely not having a value. A DBNull object represents the nonexistent column