SQL查询排名函数实例

2020-07-25 12:45:41

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在实际开发中经常会遇到计算某个字段的排名的情况

如下表：totak_sales

//img.jbzj.com/file_images/article/201606/2016060811050012.jpg

现在又如此要求：按sales的逆序排序，要求添加一个sales_rank字段，显示排名顺序

方法：

复制代码代码如下:

SELECT a1.Name, a1.Sales, COUNT(a2.sales) Sales_Rank
FROM Total_Sales a1, Total_Sales a2
WHERE a1.Sales <= a2.Sales or (a1.Sales=a2.Sales and a1.Name = a2.Name)
GROUP BY a1.Name, a1.Sales
ORDER BY a1.Sales DESC, a1.Name DESC;

结果：

//img.jbzj.com/file_images/article/201606/2016060811050013.jpg
或：

复制代码代码如下:

SELECT a1.Name, a1.Sales, COUNT(a2.sales) Sales_Rank
FROM Total_Sales a1, Total_Sales a2
WHERE a1.Sales < a2.Sales or (a1.Sales=a2.Sales and a1.Name = a2.Name)
GROUP BY a1.Name, a1.Sales
ORDER BY a1.Sales DESC, a1.Name DESC;

结果：

//img.jbzj.com/file_images/article/201606/2016060811050014.jpg

由上面的方案，我们可以继续推测，如何选出某项来呢？

比如排名为5的那项内容：

复制代码代码如下:

SELECT * from
(
SELECT a1.Name, a1.Sales, COUNT(a2.sales) Sales_Rank
FROM Total_Sales a1, Total_Sales a2
WHERE a1.Sales < a2.Sales or (a1.Sales=a2.Sales and a1.Name = a2.Name)
GROUP BY a1.Name, a1.Sales
ORDER BY a1.Sales DESC, a1.Name DESC
) as tab WHERE tab.sales_rank=5;

//img.jbzj.com/file_images/article/201606/2016060811050015.jpg