为年度报告选择记录（过去 3 年）

Question

考虑以下 SQL 语句：

DECLARE @CustomerId INT = 48;
DECLARE @CurrentYear INT = DATEPART(YEAR, GETDATE());

SELECT
    YEAR(o.OrderDate) AS Year,
    0 AS Month,
    SUM(o.GrandTotal) AS GrandTotal
FROM [Order] o
WHERE
    o.CustomerId = @CustomerId AND
    o.OrderTypeId = 4 AND
    o.IsVoid = 0 AND
    YEAR(o.OrderDate) BETWEEN @CurrentYear - 2 AND @CurrentYear
GROUP BY
    YEAR(o.OrderDate)

正确地产生结果：

2012, 0, 89.00
2011, 0, 230.00
2010, 0, 450.0

但是，如果另一个客户仅在 2011 年下订单，我需要生成另外 2 行（尽管值为 0）：

2011, 0, 230.00
2012, 0, 0
2010, 0, 0

我应该如何正确地做到这一点？请注意，将生成过去 3 年的报告。

第四次更新 我按照建议修改了代码：

DECLARE @CustomerId INT = 48;
DECLARE @CurrentYear INT = YEAR(GETDATE());

DECLARE @years TABLE (
    yr INT
);
INSERT INTO @years VALUES
    (@CurrentYear),
    (@CurrentYear - 1),
    (@CurrentYear - 2)

这会产生如下结果集（我已经检查过并确保是这种情况）。

2012
2011
2010

然后我加入表格（RIGHT JOIN）如下：

SELECT
    y.yr AS Year,
    0 AS Month,
    SUM(ISNULL(o.GrandTotal, 0)) AS GrandTotal
FROM [Order] o
RIGHT JOIN @years y ON y.yr = YEAR(o.OrderDate)
WHERE
    o.CustomerId = @CustomerId AND
    o.OrderTypeId = 4 AND
    o.IsVoid = 0
GROUP BY
    y.yr

但是，考虑到客户还没有下订单，所以，这需要产生 3 行的零值。但是，建议的这些解决方案都没有做到这一点。

最终更新 [已解决]： where 子句阻止这些行出现在最终结果集中。所以，正如 Darvin 所建议的，我只是用 AND 替换了 WHERE 子句，问题就消失了。

SELECT
    y.yr AS Year,
    0 AS Month,
    SUM(ISNULL(o.GrandTotal, 0)) AS GrandTotal
FROM [Order] o
RIGHT JOIN @years y ON y.yr = YEAR(o.OrderDate) AND
    o.CustomerId = @CustomerId AND
    o.OrderTypeId = 4 AND
    o.IsVoid = 0
GROUP BY
    y.yr

Answer 1

我在小提琴中编写了示例代码。 http://sqlfiddle.com/#!3/eddfe/9/0希望对您有所帮助。

这个想法是您创建一个包含所有年份的 UDF，然后对该表进行外部联接。

Answer 2

以下内容如何：

DECLARE @CustomerId INT = 48; 
DECLARE @CurrentYear INT = DATEPART(YEAR, GETDATE());  

;with years as 
( 
SELECT YEAR(GETDATE()) as yr 
UNION ALL SELECT YEAR(DATEADD(YY,-1,GETDATE())) 
UNION ALL SELECT YEAR(DATEADD(YY,-2,GETDATE())) 
) 
SELECT      
years.yr 
,0 AS Month 
,SUM(ISNULL(o.GrandTotal,0)) AS GrandTotal  
FROM years 
LEFT OUTER JOIN Order o  
ON YEAR(o.OrderDate) = years.yr 
AND o.customerid = @customerid
AND     o.OrderTypeId = 4  
AND     o.IsVoid = 0  
GROUP BY      
years.yr