有没有办法在嵌套的 WITH 语句中包含 DELETE FROM 语句？

Posted 2023-03-29

【中文标题】有没有办法在嵌套的 WITH 语句中包含 DELETE FROM 语句？

【英文标题】：Is there a way to include a DELETE FROM statement in a nested WITH statement?

【发布时间】：2021-10-26 18:38:09

【问题描述】：

我试图通过创建另一个表来删除重复项，但我无法包含 delete from 语句。我在 SQL Server 中有代码，但我正在尝试将其转换为 Oracle。我尝试将 select 替换为 delete from 但出现错误：缺少 SELECT 关键字。

代码如下：

WITH RowNumCTE AS(
SELECT t.* ,
    ROW_NUMBER() OVER (
    PARTITION BY ParcelID,
                PropertyAddress,
                SalePrice,
                SaleDate,
                LegalReference
                ORDER BY
                    UniqueID
                    ) t
                    
FROM nashvillehousing t
--Order by parcelid;
) 
SELECT *
FROM RowNumCTE
WHERE t > 1;

这里是示例数据：

https://github.com/AlexTheAnalyst/PortfolioProjects/blob/main/Nashville%20Housing%20Data%20for%20Data%20Cleaning.xlsx

预期结果应该是 104 个删除的重复条目。

【问题讨论】：

Oracle 不支持使用 With 子句删除。请发布您的示例数据和预期结果。

嗨 Ankit，我发布了示例数据和预期结果

请发布几行有问题的数据，而不是作为链接。

【参考方案1】：

您可以在 ROWID 伪列上关联：

DELETE FROM nashvillehousing
WHERE ROWID IN (
  SELECT ROWID
  FROM   (
    SELECT ROW_NUMBER() OVER (
             PARTITION BY ParcelID, PropertyAddress, SalePrice, SaleDate, LegalReference
             ORDER BY UniqueID
           ) AS rn       
    FROM nashvillehousing
  )
  WHERE  rn > 1
)

如果你真的想使用子查询分解子句 (WITH) 那么：

DELETE FROM nashvillehousing
WHERE ROWID IN (
  WITH sqfc (rn) AS (
    SELECT ROW_NUMBER() OVER (
             PARTITION BY ParcelID, PropertyAddress, SalePrice, SaleDate, LegalReference
             ORDER BY UniqueID
           )
    FROM nashvillehousing
  )
  SELECT ROWID
  FROM   sqfc
  WHERE  rn > 1
)