ORA-06550 , wrong number or types of arguments in call to Oracle Stored Procedure - ado.net

Question

I have a stored procedure which has one in parameter and one out parameter as follows:
create or replace procedure worker_name (w_id in number, w_first out worker.first_name%type) is
Begin
select first_name into w_first
from worker
where worker_id = w_id;
end;
Code to call this stored procedure:
public DataTable <b>GetEmployeeName</b>(int _employeeID)
{
ArrayList arrEmployeeName = new ArrayList();
OracleParameter paramEmployeeId = new OracleParameter(":employeeid", _employeeID);
arrEmployeeName.Add(paramEmployeeId);
DataLayer obj = new DataLayer();
DataTable tblEmployee = obj.<b>GetData</b>("macw_conv.worker_name", arrEmployeeName, "SP");
if (tblEmployee.Rows.Count > 0)
{
return tblEmployee;
}
return null;
}
public DataTable <b>GetData</b>(string query, ArrayList parameters,string queryType)
{
//DataTable dt = new DataTable();
try
{
_con =
new OracleConnection(Oradb);
_con.Open();
_cmd = new OracleCommand(query, _con);
if (_cmd.Connection.State == ConnectionState.Open)
{
if (queryType == "SP" && parameters != null)
{
_cmd.CommandType = CommandType.StoredProcedure;
if (parameters.Count > 0)
{
foreach (OracleParameter param in parameters)
{
_cmd.Parameters.Add(param);
}
}
}
}
DataSet ds = new DataSet();
OracleDataAdapter da = new OracleDataAdapter(_cmd);
da.Fill(ds);
if (ds.Tables.Count > 0)
{
return ds.Tables[0];
}
return null;
}
I guess I'm unable to see the obvious error. It's something about the data type mismatch between the out parameter in the stored procedure and output parameter in the code. Any kind of help is appreciated.
Thanks!
I figured out the issue: it was because the datatype of the variable that is saving the out parameter was not handled properly. I changed the code as follows:
try
{
_con = new OracleConnection(Oradb);
_cmd = _con.CreateCommand();
_cmd.CommandType = CommandType.StoredProcedure;
_cmd.CommandText = "macw_conv.worker_name";
OracleParameter inobj1 = _cmd.Parameters.Add("w_id", OracleDbType.Int32,50);
inobj1.Direction = ParameterDirection.Input;
inobj1.Value = _employeeID;
OracleParameter inobj2 = _cmd.Parameters.Add("w_last", OracleDbType.Int32, 50);
inobj2.Direction = ParameterDirection.Input;
inobj2.Value = String.IsNullOrEmpty(_lastName) ? null : _lastName;
OracleParameter outobj = _cmd.Parameters.Add("w_first", OracleDbType.Varchar2, 50);
outobj.Direction = ParameterDirection.Output;
_con.Open();
_cmd.ExecuteNonQuery();
_employeeName = ((OracleString) _cmd.Parameters[1].Value).ToString();
_cmd.Dispose();
_con.Close();
}
catch (OracleException ex)
{
Console.WriteLine(ex.Message);
}
return _employeeName;

Answer 1

Try
public DataTable GetEmployeeName(int _employeeID)
{
ArrayList arrEmployeeName = new ArrayList();
OracleParameter paramEmployeeId = new OracleParameter("employeeid", _employeeID);
arrEmployeeName.Add(paramEmployeeId);
OracleParameter paramEmployeeFirst = new OracleParameter("first", OracleDbType.Varchar2, ParameterDirection.Output);
arrEmployeeName.Add(paramEmployeeFirst);
DataLayer obj = new DataLayer();
DataTable tblEmployee = obj.GetData("macw_conv.worker_name(:1,:2)", arrEmployeeName, "SP");
if (tblEmployee.Rows.Count > 0)
{
return tblEmployee;
}
return null;
}