PostgreSQL:获取倒数第二个 MAX(date)

Question

我在 PostgreSQL 中有两个 View 。一个获取每个组织的最新总量。另一种观点是获取每个组织的倒数第二个最近的总金额，这里是问题:How to get the second to last MAX(date) in PostgreSQL?这是我的代码(请注意，“日期”是我的专栏之一，而不是函数):

CREATE VIEW vw_totaaldossiers AS
SELECT SUM(aantal) as totaal
FROM _dossier i1
WHERE date = (
    SELECT MAX(date) 
    FROM _dossier i2 
    WHERE i2.instantie = i1.instantie 
    GROUP BY i2.instantie
);

CREATE VIEW v2_relatiefdossiers AS
SELECT SUM(aantal) as relatief
FROM _dossier i3
WHERE date = (
    SELECT /* Here comes the second to last MAX(date) */ 
    FROM _dossier i4
    WHERE i4.instantie = i3.instantie
    GROUP BY i4.instantie
);

感谢您的帮助!

Answer 1

SELECT date 
FROM _dossier i2 
WHERE i2.instantie = i1.instantie 
GROUP BY i2.instantie
ORDER BY date DESC LIMIT 1 OFFSET 1