急急急急急！php 怎么调用oracel自定义函数？？？

我的写法如下  $strSql= "   SELECT apps.bg_invalid_pr(215,'IT201115',1) as BUYER_NAME FROM dual ";
  $conn =@odbc_connect('dsnOracle','bgdevlp','bg1devlp',SQL_CUR_USE_ODBC) or die ("连不上数据源");
  $result =odbc_do($conn,$strSql)or die("执行不到声明");//此处报错....
  while(odbc_fetch_row($result)){
     $BUYER_NAME =odbc_result($result,2);
echo " MM NN PP ";
     echo $BUYER_NAME;
  } 报错内容为："ORA-00904" 请问该怎么调用？？