Question

我正尝试使用cte从与外科医生名称'Lucille Torres'相关的表'exchange_transactions'中删除重复的行。 transaction_id列应该是唯一的，但是在这种情况下是重复的，因此尝试删除它们。我尝试了这段代码，但似乎没有用。将“ DELETE”替换为“ SELECT *”会显示我要删除的所有行。我在做什么错了？

WITH cte AS (
    SELECT 
        transaction_id,
        surgeon,  
        ROW_NUMBER() OVER (
            PARTITION BY 
                transaction_id
        ) row_num
        FROM exchange_transactions)
DELETE FROM cte
WHERE surgeon = 'Lucille Torres' AND row_num > 1

Answer 1

使用ROWID列获取每个不会删除的transaction_id的最小值：

delete from exchange_transactions
where surgeon = 'Lucille Torres'
and exists (
  select 1 from exchange_transactions t
  where t.surgeon = exchange_transactions.surgeon
    and t.transaction_id = exchange_transactions.transaction_id 
    and t.rowid < exchange_transactions.rowid
)

Answer 2

直接从CTE删除在SqLite中不起作用。

但是如果该表具有主键（例如id）
那么CTE的结果可用于删除。

例如：

WITH CTE_DUPS AS
(
  SELECT id,
  ROW_NUMBER() OVER (
      PARTITION BY surgeon, transaction_id
      ORDER BY id) AS rn
  FROM exchange_transactions
  WHERE surgeon = 'Lucille Torres'
)
DELETE 
FROM exchange_transactions
WHERE id IN (select id from CTE_DUPS where rn > 1)

在 db <>小提琴here

上进行测试

删除特定行-SQLite

2 个答案: