????1.?????????????????????????械??????????????????????????谢???械????????????????????? employee ?????????name???小???????????????????????????????械?????????????????????????????????????????些?????????SQL??????貌????????????????????????????????????????t?????些??????SQL??????????sql?????????????????
??????1?????????????????????????????????or??
????select *from tb_user where fd_userid=19 or fd_userid=21;???????fd_userid??????????????谩?
?????????? where fd_userid in(19??21)
??????2?????????????union??
??????3?????????????not????????????????妾�
??????4??????????????校??纾簊elect * from tb_a where fd_value+=100?????????fd_value??????????????谩?
??????5???????????????and????????between…and…?纾簑here fd_time>100 and fd_time<120????????fd_time between 100 and 120??
??????6?????????????like???????????“%”??“_”??????纾�“%bn” “_bn”??
??????7??????????????
??????8?????????having??????????蔚?????
??????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???