asp.net - 如何使用 sql server 替换数据表中的名称

Question

我想替换 sql server 记录列表中重复的客户名称

下面是查询结果的样子...

CustomerName      ||      Product

CustomerA         ||      Product    X
CustomerA         ||      Product    y
CustomerA         ||      Product    z
CustomerB         ||      Product    i  
CustomerB         ||      Product    j  

我想得到如下结果...

CustomerName      ||      Product

CustomerA         ||      Product    X
"No Name"         ||      Product    y
"No Name"         ||      Product    z
CustomerB         ||      Product    i  
"No Name"         ||      Product    j  

请建议，实现上述结果的最佳方法是什么......

谢谢阿曼

Answer 1

如果您希望或需要将其作为查询来执行，您可以使用该ROW_NUMBER()函数来确定每个客户的“第一个”产品是什么，哪些不是。在这里，我将“第一个”定义为具有词法上最小的产品名称（小提琴）：

;WITH CustomerProducts AS
(
    SELECT CustomerName, Product, 
        ROW_NUMBER() OVER(PARTITION BY CustomerName ORDER BY Product) rn
    FROM Table1
)
SELECT CASE WHEN rn=1 THEN CustomerName ELSE '"Same Customer"' END CustomerName,
    Product
FROM CustomerProducts
ORDER BY CustomerProducts.CustomerName, Product