sql下令未正确结束

update? a set a.rkrq=REPLACE(b.createdate,'-','') from ht_zygl a join sherc_res b on a.id=b.id
报错：sql命令未正确结束

------解决方法--------------------
ORACLE和SQL SERVER的SQL语法是不同的，特别是UODATE语句。ORACLE中这么写UPDATE语句是错误的。你可以试试下面的语句：
update ht_zygl
set rkrq = ( select REPLACE(createdate, '- ', ' ') from sherc_res where a.id=ht_zygl.id )
where exists ( select REPLACE(createdate, '- ', ' ') from sherc_res where a.id=ht_zygl.id )
?