Stored function

Question

Hi guys!
I have a stored function which searches if a product exists in the DB and
return the appropriate value, something like a bool variable (here there is a
problem too, because if it returns a bool value, I can't find this tipe in ODP
and I must use number and decimal types).
Anyway, the function works perfectly but I have I problem with mapping the
response value in ODP.I put it the first in ParamCollection, I have assigned
it the correct type, so I can't figure out why I get this message
ORA-22060: argument [{0}] is an invalid or uninitialized number
CREATE OR REPLACE PROCEDURE "ADMIN"."PRODUCTEXISTS"
Iname in varchar2,
Imanufacturer in varchar2
return number is
b number(1);
nr number(4);
cursor c is
SELECT product FROM products
WHERE name=Iname AND manufacturer=Imanufacturer;
begin
b:=0;
OPEN c;
LOOP
FETCH c INTO nr;
IF c%FOUND THEN
b:=1;
END IF;
EXIT WHEN b=1 OR c%NOTFOUND;
END LOOP;
CLOSE c;
RETURN b;
end;
This is the cs procedure:
public bool PRODUCTS_CheckProduct(string name, string manufacturer)
               OracleCommand cmd = new OracleCommand("PRODUCTEXISTS", dbConn);
               cmd.CommandType = CommandType.StoredProcedure;
               OracleParameter [] prm = new OracleParameter[3];
               prm[1] = cmd.Parameters.Add("name", OracleDbType.Varchar2, name, ParameterDirection.Input);
               prm[2] = cmd.Parameters.Add("manufacturer", OracleDbType.Varchar2, manufacturer, ParameterDirection.Input);
               prm[0] = cmd.Parameters.Add("RetVal", OracleDbType.Decimal, ParameterDirection.ReturnValue);
               prm[0].Size=1;
               dbConn.Open();
               cmd.ExecuteNonQuery();
               dbConn.Close();
               if (prm[2].Value.ToString())               
                    return true;
               else
                    return false;

Answer 1

When binding function parameters by position, the
function return value comes first.
And you want a stored function, not a stored procedure.
Your c# code should be something like:
      public static OracleConnection connect()
        OracleConnection con = new OracleConnection(...);
        con.open();
        return con;
      using (OracleConnection con = connect())
        OracleCommand cmd = new OracleCommand("PRODUCTEXISTS", con);
        cmd.CommandType = CommandType.StoredProcedure;
        OracleParameter rv = cmd.Parameters.Add("RetVal", OracleDbType.Decimal, ParameterDirection.ReturnValue);     
        rv.Size=1;
        cmd.Parameters.Add("name", OracleDbType.Varchar2, name, ParameterDirection.Input);
        cmd.Parameters.Add("manufacturer", OracleDbType.Varchar2, manufacturer, ParameterDirection.Input);
        cmd.ExecuteNonQuery();
        OracleDecimal d = (OracleDecimal)rv.Value;
        if (d == 1)
          return true;
        else
          return false;
      }David