Question

有没有更好的方法来创建case表达式而无需对其进行硬编码？

例如。

            SELECT
                CASE
                        WHEN PRICE BETWEEN 1 AND 10 THEN '$1~$10'
                        WHEN PRICE BETWEEN 11 AND 20 THEN '$11~$20'
                        WHEN PRICE BETWEEN 21 AND 30 THEN '$21~$30'
                        WHEN PRICE BETWEEN 31 AND 40 THEN '$31~$40'
                        WHEN PRICE BETWEEN 41 AND 50 THEN '$41~$50'
                END AS PRICE_RANGE,
                SUM(TRANSACTION_COUNT),
                SUM(TRANSACTION_AMT)
            FROM SALES 
            WHERE
                CLR.DW_NET_PD_AMT BETWEEN 1 AND 10
                OR CLR.DW_NET_PD_AMT BETWEEN 11 AND 20
                OR CLR.DW_NET_PD_AMT BETWEEN 21 AND 30
                OR CLR.DW_NET_PD_AMT BETWEEN 31 AND 40
                OR CLR.DW_NET_PD_AMT BETWEEN 41 AND 50
           GROUP BY 1;

我正在尝试根据上面显示的价格范围对价格进行分类。我需要将面额从$ 1- $ 500的钞票分类为10。

Answer 1

您可以按以下方式重写查询：

您的输出将是：price-mod（price，10）

SELECT
    price - mod(price, 10) as 'Min limit',
    price + 10 - mod(price, 10) as 'Max limit' ... and so on

您可以使用模式将SELECT的输出转换为字符串。但是我专注于数学表达式以减少您的代码行。

因此，您可以通过这种方式删除CASE

Answer 2

我不会生成从$ 1到$ 500的系列

但是我正在运行时创建一个。

假设您正在使用SQL SERVER

SELECT '$'+CONVERT(VARCHAR(100),PRICE/10*10+1)+'~$'+CONVERT(VARCHAR(100),(PRICE/10+1)*10)

Answer 3

尝试一下。

SELECT '$' + CAST((@price / 10) * 10 + 1 AS varchar) + '~$' + CAST((@price / 10) * 10 + 10 AS varchar) AS PRICE_RANGE
      ,SUM(TRANSACTION_AMT)
FROM SALES 
WHERE CLR.DW_NET_PD_AMT BETWEEN 1 AND 10
OR CLR.DW_NET_PD_AMT BETWEEN 11 AND 20
OR CLR.DW_NET_PD_AMT BETWEEN 21 AND 30
OR CLR.DW_NET_PD_AMT BETWEEN 31 AND 40
OR CLR.DW_NET_PD_AMT BETWEEN 41 AND 50
GROUP BY 1;

在没有硬编码的情况下重复模式（Netezza SQL）

3 个答案: