将 DELETE FROM 与 LEAD 函数一起使用

Question

使用 SQL Server 2014，我有一个 table 可以跟踪收银机的销售情况。如果注册操作员错误地扫描了一个项目，它将创建两条记录 - 一条 SALE 条记录和一条 VOID 条记录。

TRX_ID   LINE_ID   STS     ITEM_DESC
-----------------------------------------------------
123456   1         Sale    Sunglasses Mens RS124
123456   2         Void    Sunglasses Mens RS124
123456   3         Sale    Sunglasses NXR RS977
123456   4         Void    Sunglasses NXR RS977
123456   5         Sale    Sunglasses Unisex RS355

123678   1         Sale    Sunglasses Womens RS124w
123678   2         Void    Sunglasses Womens RS124w
123678   3         Sale    Sunglasses Womens RS977w
123678   4         Sale    Sunglasses Womens RS977w
123678   5         Sale    Sunglasses Unisex RS355w

如果交易中的以下项目已作废 (STS='VOID')，我需要编写一个查询来删除记录，只保留 'net' 个交易。

我正在使用 LEAD 让查询检查以下记录，我只是不知道如何将 DELETE FROM 和 LEAD 组合在一起。我尝试使用此查询未成功：

DELETE FROM SALES 
WHERE xxx IN (SELECT 
                  TRX_ID, LINE_ID, LEAD (T1.STS, 1, 0) OVER (PARTITION BY T1.TRX_ID ORDER BY T1.LINE_ID)  NEXT_STS
              FROM SALES_TRANSACTIONS T1) 
WHERE NEXT_STS = 'V'

例外结果：以下记录被删除：

TRX_ID   LINE_ID   STS     ITEM_DESC
----------------------------------------------------
123456   1         Sale    Sunglasses Mens RS124
123456   2         Void    Sunglasses Mens RS124
123456   3         Sale    Sunglasses NXR RS977
123456   4         Void    Sunglasses NXR RS977
123678   1         Sale    Sunglasses Womens RS124w
123678   2         Void    Sunglasses Womens RS124w

Answer 1

您可以通过多种方式做到这一点。一种是在常见的 table 表达式中使用 lead，然后从中删除：

with extra as (
    select sts,
           lead(sts) over (partition by trx_id order by line_id) leadsts
    from   sales
)
delete 
from   extra
where  'Void' in (sts, leadsts);

将 DELETE FROM 与 LEAD 函数一起使用

Using DELETE FROM with LEAD function

sql

sql-server

subquery

lead