Question

我有物品价格的db日志。有时（通常是每个月）新的状态将价格存储到db中。每个项目都有uniqueid。它每个月都不会发生变化。

我已经构建了示例数据库：

我需要检测商品价格变化。例如如果2013-01-01的item1价格为122，则2013-02-01为122，2013-03-01为124

选择应显示1行 itemname = item1，oldPrice = 122，newPrice = 124，dateCHanged = 2013-03-01

Answer 1

这应该有效：

with x as (
    select i.*, s.datecreated, row_number() over (partition by uniqueid order by datecreated) as rn
    from items i
    inner join states s on i.stateid = s.id
)
select x1.uniqueId, x1.price as oldPrice, x2.price as newPrice, x2.dateCreated as dateChanged
from x x1
inner join x x2 on x1.uniqueid = x2.uniqueid
--and datediff(month, x1.datecreated, x2.datecreated) = 1
and x1.rn - x2.rn = 1
and x1.price <> x2.price

SQL检测存储在数据库中的日志中的更改

1 个答案: