sql时间戳按月份聚合

emer 发布于 2019-4-9 10:04 3516 次阅读

create_time为时间格式(字段名create_time 根据自己表字段修改,数据库中存为201610071202）

SELECT DATE_FORMAT(create_time,'%Y%u') weeks,COUNT(id) COUNT FROM role GROUP BY weeks; SELECT DATE_FORMAT(create_time,'%Y%m%d') days,COUNT(id) COUNT FROM role GROUP BY days; SELECT DATE_FORMAT(create_time,'%Y%m') months,COUNT(id) COUNT FROM role GROUP BY months;

create_time为时间戳格式(字段名create_time 根据自己表字段修改,数据库中存为1474959640）：

SELECT FROM_UNIXTIME(create_time,'%Y%u') weeks,COUNT(id) COUNT FROM role GROUP BY weeks; SELECT FROM_UNIXTIME(create_time,'%Y%m%d') days,COUNT(id) COUNT FROM role GROUP BY days; SELECT FROM_UNIXTIME(create_time,'%Y%m') months,COUNT(id) COUNT FROM role GROUP BY months;

        var sqls={ 
    
        //查询文章  多表join连接 
    
        articleSql:"select a.*,b.*,c.username from emlog_blog  as a  left JOIN emlog_sort AS b on a.sortid =b.sid LEFT JOIN emlog_user as c ON a.author=c.uid WHERE checked='y' and  hide='n' order by date desc limit ?,?;select count(*) as total from emlog_blog;SELECT gid,title,views FROM emlog_blog ORDER BY views desc limit 0,5;", 
    
        //查询分类 按分类聚合 
    
        tagSql:"SELECT COUNT(*) as count,sid,sortname FROM emlog_sort as a,emlog_blog as b WHERE a.sid=b.sortid GROUP BY sortname order by count desc;" 
    
        }; 
    
        module.exports=sqls;

mysql中本身支持一种更好的方法来达到上面的效果，那就是使用SQL_CALC_FOUND_ROWS和FOUND_ROWS()函数。见：http://dev.mysql.com/doc/refman/5.0/en/information-functions.html#function_found-rows
应用举例：

mysql>
SELECT SQL_CALC_FOUND_ROWS * FROM
tbl_name
1

->
WHERE id > 100 LIMIT 10;
1

mysql>
SELECT FOUND_ROWS();