mysql 把date类型数据查出来后按周，按月分组

原本的SQL和查出的结果如下：

    SELECT
        biz_day,
        record.amount 
    FROM
        ods_sale_pay_record record
    WHERE
        project.delete_flag = 'N' 
        AND ( record.biz_day >= '2021-10-01' AND record.biz_day <= '2021-10-31' 
        OR record.biz_day >= '2022-01-01' AND record.biz_day <= '2022-01-31'  )

结果：

现要求按照月份为维度汇总数据，可以使用DATE_FORMAT函数
修改后的SQL如下：

    SELECT
        DATE_FORMAT(biz_day,'%Y%m') months,
        SUM( record.amount ) 'amount'
    FROM
        ods_sale_pay_record record
    WHERE
        record.status_code = 'PAY_RECORD_PAID' 
        AND ( record.biz_day >= '2021-10-01' AND record.biz_day <= '2021-10-31' 
        OR record.biz_day >= '2022-01-01' AND record.biz_day <= '2022-01-31'  )
    GROUP BY
        record.biz_day 

结果如下：

拓展：
如果想要按照天、周、月等不同的粒度对数据进行分组统计也可以参考如下的语法：

1）按天统计：

select DATE_FORMAT(biz_day,'%Y%m%d') days,SUM( record.amount ) 'amount' from test group by biz_day; 

2）按周统计：

select DATE_FORMAT(biz_day,'%Y%u') weeks,SUM( record.amount ) 'amount' from test group by biz_day; 

3）按月统计:

select DATE_FORMAT(biz_day,'%Y%m') months,SUM( record.amount ) 'amount' from test group by biz_day;