一个最简单的C#调用ORACLE存储过程都出错，求教
ORACLE存储过程如下: 就是执行删除数据库存中一些数据
create or replace procedure WCL_2
(
  tiaojian IN VARCHAR ,
  result OUT NUMBER, -- '2' 成功，'1'失败
  p_nErrCode OUT NUMBER,
  p_vErrText OUT VARCHAR2
)
is
BEGIN
  IF tiaojian ='1' THEN  
  delete from jcdbm_zddr a where a.zdsl=30;
  END IF; --条件"1" 的 end if

  Commit;
  result := 2;
  p_nErrCode := 0;
  p_vErrText := '成功';
  return;

EXCEPTION
  --失败数据回滚，显示错误代码！
  WHEN OTHERS THEN
  Rollback;
  result := 1;
  p_nErrCode := SQLCODE;
  p_vErrText := SQLERRM;
  return;
END WCL_2;

C#代码如下：
  private void button5_Click(object sender, EventArgs e)
  {
  OracleConnection conn = new OracleConnection(Dboperation.connectionstring);
  OracleCommand cmd = new OracleCommand();
   
  cmd.CommandType = System.Data.CommandType.StoredProcedure;
  cmd.CommandText = "WCL_2";

  OracleParameter param = new OracleParameter("tiaojian", OracleType.VarChar,10); 
  param.Direction = ParameterDirection.Input;
  param.Value = "1";
  cmd.Parameters.Add(param);
   
  try
  {
  conn.Open();
  cmd.Connection = conn;
  cmd.ExecuteNonQuery();
  }
  catch (OracleException ex)
  {
  string errorMessage = "Code: " + ex.Code + "\n" +
  "Message: " + ex.Message + "\n" + ex.ErrorCode + "\n" + ex.Source + "\n" + ex.Data + "\n" + ex.InnerException + "\n" + ex.StackTrace + "\n" + ex.TargetSite + "\n";
  MessageBox.Show(errorMessage);

  //
  }
  conn.Close();
  }
搞不懂，存储过程测试过都成功的，但是调用的时候提示参数个数或类型不对，出错画面如下：

errorMessage "Code: 6550\nMessage: ORA-06550: line 1, column 7:\nPLS-00306: wrong number or types of arguments in call to 'WCL_2'\nORA-06550: line 1, column 7:\nPL/SQL: Statement ignored\n\n-2146232008\nSystem.Data.OracleClient\nSystem.Collections.ListDictionaryInternal\n\n 在 System.Data.OracleClient.OracleConnection.CheckError(OciErrorHandle errorHandle, Int32 rc)\r\n 在 System.Data.OracleClient.OracleCommand.Execute(OciStatementHandle statementHandle, CommandBehavior behavior, Boolean needRowid, OciRowidDescriptor& rowidDescriptor, ArrayList& resultParameterOrdinals)\r\n 在 System.Data.OracleClient.OracleCommand.ExecuteNonQueryInternal(Boolean needRowid, OciRowidDescriptor& rowidDescriptor)\r\n 在 System.Data.OracleClient.OracleCommand.ExecuteNonQuery()\r\n 在 yw.frm_mlqhyw.button5_Click(Object sender, EventArgs e) 位置 E:\\设计练习\\yw\\yw\\yw\\frm_mlqhyw.cs:行号 143\nVoid CheckError(System.Data.OracleClient.OciErrorHandle, Int32)\n" string
  望高手能指教一下

------解决方案--------------------
后面3个返回的参数，也要创建吧
我的异常网推荐解决方案：oracle存储过程,http://www.aiyiweb.com/oracle-develop/177537.html