select af.keynode into kn from APPFOUNDATION af where af.appid=aid and af.foundationid=fid;-- 有into,正确编译 select af.keynode from APPFOUNDATION af where af.appid=aid and af.foundationid=fid;-- 没有into,编译报错,提示:Compilation Error: PLS-00428: an INTO clause is expected in this SELECT statement
3.在利用select...into...语法时,必须先确保数据库中有该条记录,否则会报出"no data found"异常。