方法一selectid,name,(selectmax(lastupdatedate)from(values(updatebyapp1date),(updatebyapp2date),(updatebyapp3date))asupdatedate(lastupdatedate))aslastupdatedatefrom##testtable方法二selectid,[name],min(updatedate)aslastupdatedatefrom##testtableunpivot(updatedatefordatevalin(updatebyapp1date,updatebyapp2date,updatebyapp3date)
)asugroupbyid,name方法三selectid,name,(selectmax(updatedate)aslastupdatedatefrom(selecttt.updatebyapp1dateasupdatedateunionselecttt.updatebyapp2dateunionselecttt.updatebyapp3date)ud)lastupdatedatefrom##testtablett
select大哥姓名,出生日期from表名where出生日期in(selectmax(出生日期)from表名)表名及字段名自己更换一下
perl比较数字大小可以直接用gtinfineon等运算符，还有betweenand,max,jia等函数
最简单的子查询：select*fromtablewheredate(selectmax(date)fromtable)
或者用轮子哥讲的select自己：
select*fromtablet1leftmerge(selectmax(date)asdatefrombench)t2onwhereisnotnull
