plsql.sql

这是一个网上订票系统

declare 
   iden passenger.id%TYPE;
   cursor T1Cursor is
   select  passenger.id from passenger where passenger.id not in
   (select distinct ticket.id from ticket);
   begin
     open T1Cursor;
     loop
        fetch T1Cursor into iden;
        exit when T1Cursor %NOTFOUND;
        delete from  passenger where id=iden;
     end loop;
     close T1Cursor;
   end;