Question

从mysql数据库中只删除一条记录的正确方法是什么。此查询仅用于选择一条记录。

SELECT * FROM Customers WHERE Country='Mexico' ORDER BY Country  ASC LIMIT 1;

上面的查询运行正确。但是当替换select时删除那些没有用的。

DELETE FROM Customers WHERE Country='Mexico' ORDER BY Country  ASC LIMIT 1;

我该如何解决？

Answer 1

如果您有id列，则可以使用subselect。我删除了订单，因为这与order by 'Mexico' asc相同，这是非常无用的。

    DELETE FROM Customers
WHERE (CustomerID IN ( SELECT CustomerID
                  FROM Customers where country = 'Mexico'
                  ORDER BY CustomerID ASC LIMIT 1 )) ;

Answer 2

我认为以下查询会对您有所帮助。您需要使用一些密钥ID来区分。

DELETE FROM Customers 
WHERE SOME_KEY_ID IN 
(
  SELECT SOME_RANDOM_ID FROM
  (
            SELECT B.SOME_KEY_ID SOME_RANDOM_ID  FROM Customers as B 
            where Country = 'Mexico'
            LIMIT 1
   )     as c 
 )  ;

注意：内部选择SOME_RANDOM_ID是必需的，否则sqlfiddle会抛出错误This version of MySQL doesn't yet support 'LIMIT & IN/ALL/ANY/SOME subquery':。

Reference FIDDLE Here

在mysql数据库中只删除一条记录

2 个答案: