SQL查询如何查找一月（混年）最后几个月的数据SQLServer 2008

Question

我正在创建查询以提取过去 3 个月的记录。我遇到的问题是最后 x 个月跨到前一年。我想我有一个解决方案，但我觉得有更好的方法吗？

字段：asiplayer.date_used 是日期时间字段。

下面的代码似乎有效（但我如何在 7 月测试 1 月？）

有没有更好的方法？如果是最近 6 个月怎么办，我会继续这个代码吗？

WHERE
-- ACTIVE LIST (LAST 3 MONTHS)
(

(   --Current Month is Not January or February, so all 3 months are in current year

        MONTH(CURRENT_TIMESTAMP) NOT IN (1,2) 
        AND MONTH(asiplayer.date_used) >= MONTH(DateAdd(month,-2,CURRENT_TIMESTAMP)) 
        AND YEAR(asiplayer.date_used) = YEAR(CURRENT_TIMESTAMP)
) 


    OR  --It's January so some of the months are last year

(           
        --Get November and December of the Previous Year    
        (MONTH(CURRENT_TIMESTAMP) = 1 AND   (MONTH(asiplayer.date_used) = MONTH(DateAdd(month,-2,CURRENT_TIMESTAMP)) OR MONTH(asiplayer.date_used) = MONTH(DateAdd(month,-1,CURRENT_TIMESTAMP)))
            AND YEAR(asiplayer.date_used) = YEAR(DateAdd(year,-1,CURRENT_TIMESTAMP))
        )

        OR  
            --Get January of the Current Year
            (MONTH(CURRENT_TIMESTAMP) = 1 
            AND MONTH(asiplayer.date_used) = 1 
            AND YEAR(asiplayer.date_used) = YEAR(CURRENT_TIMESTAMP)
            )

)   


    OR --It's February so some of the months are last year


(           
        --Get December of the Previous Year 
        (MONTH(CURRENT_TIMESTAMP) = 2 AND MONTH(asiplayer.date_used) = MONTH(DateAdd(month,-2,CURRENT_TIMESTAMP)) 
            AND YEAR(asiplayer.date_used) = YEAR(DateAdd(year,-1,CURRENT_TIMESTAMP))
        )

        OR  
            --Get January & February of the Current Year
            (MONTH(CURRENT_TIMESTAMP) = 2 
            AND MONTH(asiplayer.date_used) IN (1,2) 
            AND YEAR(asiplayer.date_used) = YEAR(CURRENT_TIMESTAMP)
            )

)   

)

Answer 1

Serg 提供了答案：

DATEDIFF(MONTH, asiplayer.date_used, CURRENT_TIMESTAMP) <=3

SQL查询如何查找一月（混年）最后几个月的数据SQLServer 2008

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