则非

分类

/ 注册

全部文章（共3篇）

题解 | 医院门诊复诊率与抗生素用药占比统计

with r1 as( select v2.dept, count(1) as again from visits as v1 join visits as v2 on v1.patient_id = v2.patient_id and v1.dept = v2.dept and ...

2025-09-24

0 24

题解 | 下单复盘

select c.customer_id, c.customer_name, count(distinct o.order_id) as feb_2024_order_count, round(ifnull(sum(qty*price),0),2)feb_2024_t...

2025-09-23

0 22

题解 | 统计借阅量

select book_id, book_title, sum(if(borrow_date between '2023-02-01' and '2023-02-28' ,1,0)) as feb_2023_borrows, sum(if(borrow_date be...

2025-09-19

16 20