C#

When the CommandType property is set to StoredProcedure, you should set the CommandText property to the full Oracle call syntax. The command then executes this stored procedure when you call one of the Execute methods (for example, ExecuteReader or ExecuteNonQuery).

The Connection, CommandType and CommandText properties cannot be set if the current connection is performing an execute or fetch operation.

The .NET Framework Data Provider for Oracle does not support the question mark (?) placeholder for passing parameters to an SQL statement called by an OracleCommand of CommandType.Text. In this case, named parameters must be used. For example:

SELECT * FROM Customers WHERE CustomerID = :pCustomerID

When using named parameters in an SQL statement or stored procedure, you must precede the parameter name with a colon ( . However, when referring to a named parameter elsewhere in your code (for example, when calling Add), do not precede the named parameter with a colon ( . The .NET Framework Data Provider for Oracle supplies the colon automatically.

OracleConnection conn = new OracleConnection("...");
OracleCommand cmd = conn.CreateCommand();
cmd.CommandType = CommandType.StoredProcedure;
cmd.CommandText = "myproc(:param1, :param2)";
cmd.Parameters.Add("param1", OracleType.Int32).Value = 1;
cmd.Parameters.Add("param2", OracleType.Char, 40).Value = "CodeProject");
using (conn)
{
  conn.Open();
  cmd.ExecuteNonQuery();
}

[DllImport("quickfind.dll", CharSet=CharSet.Ansi)]
static extern int QuickFindModules(
  [Out] StringBuilder nameList,
  int bufferLength);
public string FindModules()
{
  int length = 512;
  StringBuilder nameList = new StringBuilder(length); // No code duplication!
  if (QuickFindModules(nameList, length) == 0) // Just guessing at return status.
    return nameList.ToString();
  return null;
}