#!/usr/bin/ksh
RET=`sqlplus -silent rep/Ndk38f7@dw <<END
set pagesize 0 feedback off verify off heading off echo off
select decode(d1,d2,'No rows',to_char(d1)||' '||to_char(d2)) from
(select trunc(max(chg_dt)) d1 from NOT_SCHEDULED_INSTALL),
(select trunc(sysdate) d2 from dual);
exit;
END`
if [[ "$RET" = "No rows" ]] ; then
   # do something
else
  # do something else
fi