SQL按每日查询

查询一段时间内，每天有多少注册量：

select count(*) as count,RegDate from user where RegDate between "2014-01-01" and "2014-04-04" group by day(RegDate) order by RegDate;

查询结果

count   RegDate 

3          2014-01-13 16:52:19

1             2014-03-03 15:00:41

1             2014-03-10 15:35:18

1             2014-03-20 17:00:05

1             2014-03-25 14:37:11

2             2014-03-26 17:42:15

//根据要求的日期来取数据

    var sqlPeriod;

    if(period == "day"){

        sqlPeriod="day(RegDate),month(RegDate),year(RegDate)";

    }else if(period == "month"){

        sqlPeriod="month(RegDate),year(RegDate)";

    }else if(period == "year"){

        sqlPeriod="year(RegDate)";

    }else if(period == "week"){

        sqlPeriod="week(RegDate)";

    }else if(period == "quarter"){

        sqlPeriod="quarter(RegDate)";

    }

“select count(*) as count,RegDate as regDate from user where RegDate between ? and ? group by "+sqlPeriod+" order by RegDate",[startDate,endDate]