mysql统计函数

参考：

http://c.biancheng.net/mysql/function/（编程网：MySQL函数大全）

https://www.cnblogs.com/lazyInsects/p/8006388.html（mysql统计数据）

https://www.cnblogs.com/poloyy/p/12890763.html（常用函数汇总）

一，时间查询

/*查询2小时前的数据*/
select * from tableName WHERE
        create_time < DATE_SUB(NOW(), INTERVAL 2 HOUR)
#7天前
SELECT count(id) FROM rd_track_info WHERE
DATE(create_time) < DATE_SUB(CURDATE(), INTERVAL 7 DAY);

二，统计数据

/*按天统计*/
SELECT
    count(id) countNum,
    DATE(create_time) createTime
FROM
    rd_track_info
GROUP BY
    DATE(create_time)
ORDER BY
    DATE(create_time) DESC;
/*按周统计*/
SELECT
    count(id) countNum,
    WEEK(create_time) createTime
FROM
    rd_track_info
GROUP BY
    WEEK(create_time)
ORDER BY
    WEEK(create_time) DESC;


/*按月统计*/
SELECT
    count(id) countNum,
    MONTH(create_time) createTime
FROM
    rd_track_info
GROUP BY
    MONTH(create_time)
ORDER BY
    MONTH(create_time) DESC;


/*按季度统计*/
SELECT
    count(id) countNum,
    QUARTER(create_time) createTime
FROM
    rd_track_info
GROUP BY
    QUARTER(create_time)
ORDER BY
    QUARTER(create_time) DESC;

/*按年统计*/
SELECT
    count(id) countNum,
    YEAR(create_time) createTime
FROM
    rd_track_info
GROUP BY
    YEAR(create_time)
ORDER BY
    YEAR(create_time) DESC;