刪除基於另一行

行我有以下幾點：刪除基於另一行

stock | Customer 
12345 | NULL 
12345 | ABC

我想要做的就是刪除第一個在不影響第二隨時有這樣一組行：

if exists (select stock from table WHERE stock='12345' AND Customer is not null) 
      BEGIN 
       DELETE FROM table WHERE stock= '12345' AND Customer is null 
      END

該查詢有效，但我該如何更改它以便我不必指定庫存？我想保留與零客戶行是它是與該股票相關的唯一價值。

來源

2017-01-25 Patrick Schomburg

不會這項工作'如果客戶是null'您問：'我如何改變它，這樣我就不必指定股票？ ' – TheGameiswar

對不起，我應該指定。我想保留空行的客戶是它是與該股票號碼相關聯的唯一價值 –

可以使用存在：

DELETE t0 
FROM table t0 
WHERE Customer IS NULL 
AND EXISTS 
(
    SELECT 1 
    FROM table t1 
    WHERE t0.stock = t1.stock 
    AND t1.Customer IS NOT NULL 
)

這隻會刪除記錄凡客爲null，並且至少有一個記錄具有相同股票ID。

來源

2017-01-25 14:30:42

你的邏輯是相反的，你正在刪除與客戶信息 –

@ t-clausen.dk好行！只是錯誤地放在'不'.... ....固定。 –

只要做到delete from table where customer is null如果這是您唯一的要求。

來源

2017-01-25 14:30:24 Utsav

使用以下命令：

WITH CTE (stock, customer, DuplicateCount) 
AS 
(
SELECT stock, customer, 
ROW_NUMBER() OVER(PARTITION BY Stock ORDER BY customer desc) AS DuplicateCount 
FROM [Table] 
) 
DELETE 
FROM CTE 
WHERE DuplicateCount > 1 and customer is NULL 
GO

來源

2017-01-25 14:32:20 houdx

請檢查下面的SQL DELETE CTE表達內命令我使用SQL Count function with Partition By條款。爲了測試NOT NULL客戶字段值我數了每隻股票與歸檔名使我能夠去除NULL

;with cte as (
    select 
     stock, 
     Customer, 
     cnt = Count(Customer) over (partition by stock) 
    from StockCustomer 
) 
delete from cte 
where Customer is null and cnt > 0

你可以考慮像不同的情況在以下行

create table StockCustomer (stock int, Customer varchar(10)) 
insert into StockCustomer select 12345 , NULL 
insert into StockCustomer select 12345 , 'ABC' 
insert into StockCustomer select 11111 , 'XYZ' 
insert into StockCustomer select 555555 , NULL

來源

2017-01-25 14:34:54 Eralper

您可以使用cross join如下：

DELETE 
    FROM mytable 
    WHERE stock IN (
      SELECT m2.stock 
      FROM mytable m1 
      CROSS JOIN mytable m2 
      WHERE m1.customer IS NULL 
      GROUP BY m2.stock 
      HAVING count(m2.stock) > 1 
      ) 
    AND customer is NULL

來源

2017-01-25 14:39:33 apomene

刪除基於另一行

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