选择每月的最后一天

Question

I´m trying to work out this select but not getting anywhere-. Please help. many thanks, Louise

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I need to get the sum of sales for the last date of each month group by custom and by month(fecha)

for example, for custom ='q' in month=8 I have 3 items in the last day of the month ='2014-08-15' totalling 13 and so on

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DECLARE @sales TABLE
(custom VARCHAR(10) NOT NULL,
fecha DATE NOT NULL,
sales NUMERIC(10, 2) NOT NULL);

INSERT INTO @sales(custom, fecha, sales)
VALUES ('q', '20140708', 51),
('q', '20140712', 3), 
('q', '20140712', 3), 
('q', '20140712', 4), 
('q', '20140811', 3), 
('q', '20140812', 1),
('q', '20140815', 5),
('q', '20140815', 6),
('q', '20140815', 2),
('q', '20140114', 7),
('q', '20140714', 24),
('q', '20140714', 24),
('x', '20140709', 25),
('x', '20140710', 16),
('x', '20140711', 36),
('x', '20140712', 23),
('x', '20140712', 35),
('x', '20140715', 57),
('c', '20140712', 97),
('c', '20140715', 71);

Answer 1

Try this. Used CTE for better code readability

;WITH cte
     AS (SELECT custom, Max(fecha) fecha
         FROM   @sales
         GROUP  BY custom, Datepart(yyyy, fecha), Datepart(mm, fecha))
SELECT b.custom, b.fecha, Sum(b.sales) [Sum]
FROM   cte a
       JOIN @sales b
         ON a.custom = b.custom
            AND a.fecha = b.fecha
GROUP  BY b.custom, b.fecha