DENSE_RANK() OVER (PARTITION BY

Question

我有下面的 SQL 查询，需要将其转换成 Sybase。

SELECT prd_name, DENSE_RANK() OVER (PARTITION BY prd_cat ORDER BY createddt) FROM product

Table 脚本：

CREATE table product(prd_name varchar(10),
                     prd_cat varchar(10), 
                     createddt datetime)
INSERT INTO product values('Product 1', 'Toy', CONVERT(DATE,'2017-05-30'))
INSERT INTO product values('Product 2', 'Toy', CONVERT(DATE,'2017-05-31'))
INSERT INTO product values('Product 3', 'Toy', CONVERT(DATE,'2017-05-31'))
INSERT INTO product values('Product 4', 'Toy1', CONVERT(DATE,'2017-05-29'))

版本：Adaptive Server Enterprise/15.7

Answer 1

某些版本的 Sybase 支持 window 函数。我假设你没有这样的版本。

您可以将其替换为相关子查询：

SELECT p.prd_name,
       (SELECT COUNT(DISTINCT createddt)
        FROM product p2
        WHERE p2.prd_cat = p.prd_cat AND p2.createddt < p.createddt
       )
FROM product p;

DENSE_RANK() OVER (PARTITION BY

Sybase Alternative for DENSE_RANK() OVER (PARTITION BY

sql

window-functions

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