Mysql 正在更新正在查询的同一个表

此查询按预期工作，并返回丢失的客户编号

SELECT *
FROM Person_Details AS b
     INNER JOIN Person_Details AS a ON a.holdername = b.holdername
                                       AND a.District = b.District
                                       AND a.Dob = b.DOb
                                       AND a.Address = b.Address
WHERE b.customer_No IS NULL limit 10

我需要做的是找到给定“holdernames”的客户编号，并在其为空时进行更新。我希望下面的更新能够起作用。但它更新了0条记录

update Person_Details as b inner join Person_Details as a
on a.holdername = b.holdername  and a.District = b.District   and a.Dob = b.DOb and a.Address = b.Address 
set b.customer_no = a.customer_No 
where b.customer_No is null

我是否正确使用带有自联接的更新

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更新：

当我用测试用例尝试它时，它按预期工作。但当我在生产服务器上使用相同的查询时，它不会更新任何行。我只是想知道我是否遗漏了一些明显的东西

create table Person_Details (holdername varchar(100), District varchar(100),
                             Dob varchar(100), Address varchar(100), customer_No int);

                             insert into Person_Details values ('shantanu', 'mumbai', '1970-11-16', 'india', 123);
                             insert into Person_Details values ('shantanu', 'mumbai', '1970-11-16', 'india', NULL);
                             insert into Person_Details values ('akbar', 'delhi', '1995-12-11', 'india', 987);


select * from  Person_Details as b inner join Person_Details as a
on a.holdername = b.holdername  and a.District = b.District  and a.Dob = b.DOb and a.Address = b.Address 
where b.customer_No is null
limit 10;

update Person_Details as b inner join Person_Details as a
on a.holdername = b.holdername  and a.District = b.District   and a.Dob = b.DOb and a.Address = b.Address 
set b.customer_no = a.customer_No 
where b.customer_No is null

尝试添加

而a.customer\u no不为空因此

update Person_Details as b inner 
join Person_Details as a 
on a.holdername = b.holdername  
and a.District = b.District
and a.Dob = b.DOb 
and a.Address = b.Address 
and a.customer_no IS NOT NULL
set b.customer_no = a.customer_No 
where b.customer_No is null

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显示示例数据集，并确保其null不为空“”两者都是不同的请参见：