orcale命令

orcale命令

update project_main b set b.KHNR =(select khzb from  test_lsd a  where a.id=b.xmid ) --将a表的khzb 的值更新到b表khnr中,条件是a.id=b.xmid

create table project_main_bak as select * from project_main    --创建project_main表的备份表