1、根據(jù)時間查詢所有用戶最新一條數(shù)據(jù)
'select user,password,max(date) as date from user group by user'
注意：此處的‘‘user,password’’不能使用“*”號代替择膝，否則會出錯（具體原因不明）
2昨凡、查詢某一用戶最新一條數(shù)據(jù)
'select * from user where user = " ' + userName + ' " order by date desc limit 1'
注意：此處的“userName”是一個變量导街，一定得注意sql語句中的雙引號
3耻蛇、返回值經(jīng)過簡單的計(jì)算
'select (number*3-2)/2 as number from user where user = " ' + userName + ' " order by date desc limit 1'
4吭从、查詢某用戶在某一時間段所有數(shù)據(jù)
'select * from user where user = " ' + userName + ' " and date > " ' + startTime + ' " and date < " ' + endTime + ' " '
