????1.?????????????????????????е??????????????????????????л???е????????????????????? employee ?????????name???С???????????????????????????????е?????????????????????????????????????????Щ?????????SQL??????ò????????????????????????????????????????t?????Щ??????SQL??????????sql?????????????????
??????1?????????????????????????????????or??
????select *from tb_user where fd_userid=19 or fd_userid=21;???????fd_userid??????????????á?
?????????? where fd_userid in(19??21)
??????2?????????????union??
??????3?????????????not????????????????檔
??????4??????????????У??磺select * from tb_a where fd_value+=100?????????fd_value??????????????á?
??????5???????????????and????????between…and…?磺where fd_time>100 and fd_time<120????????fd_time between 100 and 120??
??????6?????????????like???????????“%”??“_”??????磺“%bn” “_bn”??
??????7??????????????
??????8?????????having??????????ε?????
??????9??????distinct
??????10?????????any all????select fd_id from tb_a where fd_id<=all(select fd_id from tb_b)????????<=(select min(fd_id) from tb_b+++)
??????11???????????????SQL?????????sql???