round(avg(active_user_num)over(partition by product_id),2) as avg_active_user_num from ( select concat(substr(dt,1,4),'-',substr(dt,5,2),'-',substr(dt,7,2)) as stat_date ,product_id ,count(distinct user_id) as active_user_num from user_log where dt between...
lag(XXX,1)：上一行 lag(滑动字段, n, 填充值）over(……）：获取所在窗口范围内当前行之前的第n...
SELECTstudent_id,first_name,last_name,enrolment_date,LEAD(enrolment_date)OVER(ORDERBYenrolment_dateASC)ASnext_enr_dateFROMstudentORDERBYstudent_idASC; Result: The NEXT_ENR_DATE column shows the result of the LEAD function. It looks for the next row when ordered by enrolment_date, and displays...
The following example uses theLAGfunction to compare year-to-date sales between stores. Each record shows a store's sales and the sales of the store with the nearest lower sales. ThePARTITION BYclause is specified to divide the rows in the result set by region. TheLAGfunction is applied to...
墨墨导读:在数据科学家岗位的面试中,窗口函数(WINDOW function)是SQL函数家族中经常会被问到的主题。在本文中,我会根据面试的问题,问题模式和解决问题的基本策略向你展示一些典型的窗口函数,并提供一些示例的分步解决方案。 原文出处:https://sqlpad.io/tutorial/4-essential-sql-window-functions-and-examples-for-a...
The following example uses the LAG function to compare year-to-date sales between employees. The PARTITION BY clause is specified to divide the rows in the result set by sales territory. The LAG function is applied to each partition separately and computation restarts for each partition. The ORD...
答案: SELECT emp_name, dept_id, hire_date, LAG(emp_name, 1) OVER (PARTITION BY dept_id ORDER BY hire_date), LEAD(emp_name, 1) OVER (PARTITION BY dept_id ORDER BY hire_date) FROM employee; 解析:LAG 和 LEAD 用于返回排名中相对于当前行的指定偏移量之前和之后的数据。 62. 查询员工的...
The following example uses the LAG function to compare year-to-date sales between employees. The PARTITION BY clause is specified to divide the rows in the result set by sales territory. The LAG function is applied to each partition separately and computation restarts for each partition. The ORD...
The following example uses the LAG function to compare year-to-date sales between employees. The PARTITION BY clause is specified to divide the rows in the result set by sales territory. The LAG function is applied to each partition separately and computation restarts for each partition. The ORD...
The following example uses the LAG function to compare year-to-date sales between employees. The PARTITION BY clause is specified to divide the rows in the result set by sales territory. The LAG function is applied to each partition separately and computation restarts for each partition. The ORD...