1.要去某段时间内的数据，要求每天的数据只取id最大的一条

 

###查询去重取每天的id最大的数据#####SELECT    highPressure,    lowVoltage,    pulse,    ADDTIME,    uid,    DATE_FORMAT( uploadTime, '%Y-%m-%d' ) AS uploadTime,    id FROM    bloodpressure WHERE    id IN (    SELECT        max( id )     FROM        bloodpressure     WHERE        highPressure IS NOT NULL         AND deleteStatus = 0         AND uid = 32854         AND DATE_FORMAT( uploadTime, '%Y-%m-%d' ) >= '2017-03-15'         AND DATE_FORMAT( uploadTime, '%Y-%m-%d' ) <= '2018-12-06'     GROUP BY        DATE_FORMAT( uploadTime, '%Y-%m-%d' )     )

结果就获得想要的东西：