Can not execute a sys_refcursor function without parameters - oracle

Question

I have this sys_refcursor function in a package
function frcBaanCompanies return SYS_REFCURSOR is
x sys_refcursor;
begin
open x for select t$comp, t$cpnm from baan.tttaad100000 order by t$comp;
return x;
end;
and a net method calling this as so
listBox1.DataSource = lO.fRefCursor("priceWorx.frcBaanCompanies", null, false).Tables[0];
Here's how I call the function:
public DataSet fRefCursor(String refCursorName, IDictionary<string, string> prms, bool leaveConnectionOpen = true)
{
try
{
using (OracleCommand cmd = new OracleCommand("", conn))
{
cmd.CommandType = CommandType.StoredProcedure;
cmd.CommandText = refCursorName;
if (prms!=null) SetupParams(refCursorName, cmd, prms);
using (OracleDataAdapter da = new OracleDataAdapter(cmd))
{
if (conn.State != ConnectionState.Open)
{
conn.Open();
cmd.Connection = conn;
}
using (DataSet ds = new DataSet())
{
da.Fill(ds);
return ds;
}
}
}
}
catch (Exception ex)
{
Debugger.Break();
Debug.WriteLine(ex);
return null;
}
finally
{
if (!leaveConnectionOpen) conn.Close();
}
}
The same method works fine when called with parameters(some other cursor function, but fails with
ORA-06550: line 1, column 7:
PLS-00221: 'FRCBAANCOMPANIES' is not a procedure or is undefined
ORA-06550: line 1, column 7:
PL/SQL: Statement ignored
works fine when executed within (Oracle) sql developer too..
What am I doing wrong ?

Answer 1

This is because you can't call a function without parameters, but you could call it with null parameters. What you are currently calling when you do not input any parameters is:
FRCBAANCOMPANIES;
and this is different to
variable := FRCBAANCOMPANIES;
In the first case oracle is looking for a procedure without any return and in the second case you call your function. So you have to set the return parameter also if you do not need it.