hive 取排行第二的工资

CREATE TABLE employee(
id INT ,
salary INT );

INSERT INTO employee
SELECT 1,100
UNION ALL
SELECT 2,200
UNION ALL
SELECT 3,300;

SELECT
 coalesce(salary ,0) salary
FROM (
    SELECT
    id,
    salary,
    row_number() over( ORDER BY salary desc) num
    FROM (
        SELECT
         id,
         salary,
         row_number() over( PARTITION BY(id) ORDER BY salary) AS n
        FROM employee
        ) a
    WHERE a.n = 1
    ) b
WHERE b.num = 2;

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Hive 使用datediff函数求两个指定日期的差

datediff(endDate, startDate)