MySQL 错误 1093 - 无法在 FROM 子句中指定要更新的目标表

最近我不得不更新同一张表中的记录，如下所示：

UPDATE skills AS s, (SELECT id  FROM skills WHERE type = 'Programming') AS p
SET s.type = 'Development' 
WHERE s.id = p.id;

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您的子查询中的 inner join 是不必要的。您似乎想删除 story_category 中 category_id 不在 category 表中的条目。

取而代之的是：

DELETE FROM story_category 
WHERE category_id NOT IN (
    SELECT DISTINCT category.id 
    FROM category INNER JOIN
         story_category ON category_id=category.id);

做这个：

DELETE FROM story_category 
WHERE category_id NOT IN (
    SELECT DISTINCT category.id 
    FROM category);

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如果你做不到

UPDATE table SET a=value WHERE x IN
    (SELECT x FROM table WHERE condition);

因为它是同一张桌子，你可以欺骗和做：

UPDATE table SET a=value WHERE x IN
    (SELECT * FROM (SELECT x FROM table WHERE condition) as t)

[更新或删除或其他]

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DELETE FROM story_category
WHERE category_id NOT IN (
    SELECT cid FROM (
        SELECT DISTINCT category.id AS cid FROM category INNER JOIN story_category ON category_id=category.id
    ) AS c
)

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这就是我为将优先级列值更新 1 所做的，如果它在表中 >=1 并且在其 WHERE 子句中使用同一表上的子查询以确保至少一行包含 Priority=1（因为那是执行更新时要检查的条件）：

UPDATE My_Table
SET Priority=Priority + 1
WHERE Priority >= 1
AND (SELECT TRUE FROM (SELECT * FROM My_Table WHERE Priority=1 LIMIT 1) as t);

我知道这有点难看，但它确实工作正常。

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对于 OP 试图实现的特定查询，理想和最有效的方法是根本不使用子查询。

以下是 OP 的两个查询的 LEFT JOIN 版本：

SELECT s.* 
FROM story_category s 
LEFT JOIN category c 
ON c.id=s.category_id 
WHERE c.id IS NULL;

注意：DELETE s 将删除操作限制在 story_category 表中。
Documentation

DELETE s 
FROM story_category s 
LEFT JOIN category c 
ON c.id=s.category_id 
WHERE c.id IS NULL;

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最简单的方法是在子查询中引用父查询表时使用表别名。

例子 ：

insert into xxx_tab (trans_id) values ((select max(trans_id)+1 from xxx_tab));

将其更改为：

insert into xxx_tab (trans_id) values ((select max(P.trans_id)+1 from xxx_tab P));

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您可以将所需行的 ID 插入到临时表中，然后删除在该表中找到的所有行。

这可能是@Cheekysoft 分两步完成的意思。

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根据@CheekySoft 链接的 the Mysql UPDATE Syntax，它在底部显示。

目前，您无法在子查询中更新表并从同一个表中进行选择。

我猜您正在从 store_category 中删除，同时仍在联合中从中进行选择。

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尝试将 Select 语句的结果保存在单独的变量中，然后将其用于删除查询。

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尝试这个

DELETE FROM story_category 
WHERE category_id NOT IN (
SELECT DISTINCT category.id 
FROM (SELECT * FROM STORY_CATEGORY) sc;

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如果某些事情不起作用，则通过前门时，请走后门：

drop table if exists apples;
create table if not exists apples(variety char(10) primary key, price int);

insert into apples values('fuji', 5), ('gala', 6);

drop table if exists apples_new;
create table if not exists apples_new like apples;
insert into apples_new select * from apples;

update apples_new
    set price = (select price from apples where variety = 'gala')
    where variety = 'fuji';
rename table apples to apples_orig;
rename table apples_new to apples;
drop table apples_orig;

它很快。数据越大越好。

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这个查询怎么样希望它有帮助

DELETE FROM story_category LEFT JOIN (SELECT category.id FROM category) cat ON story_category.id = cat.id WHERE cat.id IS NULL

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就问题而言，您希望删除 story_category 中不存在于 category 中的行。

这是您用于识别要删除的行的原始查询：

SELECT * 
FROM  story_category 
WHERE category_id NOT IN (
    SELECT DISTINCT category.id 
    FROM category INNER JOIN 
       story_category ON category_id=category.id
);

将 NOT IN 与作为原始表的子查询 JOIN 组合起来似乎不必要地令人费解。这可以用 not exists 和相关子查询以更直接的方式表示：

select sc.*
from story_category sc
where not exists (select 1 from category c where c.id = sc.category_id);

现在很容易将其转换为 delete 语句：

delete from story_category
where not exists (select 1 from category c where c.id = story_category.category_id);    

这个查询可以在任何 MySQL 版本上运行，也可以在我知道的大多数其他数据库上运行。

Demo on DB Fiddle：

-- set-up
create table story_category(category_id int);
create table category (id int);
insert into story_category values (1), (2), (3), (4), (5);
insert into category values (4), (5), (6), (7);

-- your original query to identify offending rows
SELECT * 
FROM  story_category 
WHERE category_id NOT IN (
    SELECT DISTINCT category.id 
    FROM category INNER JOIN 
       story_category ON category_id=category.id);

| category_id |
| ----------: |
|           1 |
|           2 |
|           3 |

-- a functionally-equivalent, simpler query for this
select sc.*
from story_category sc
where not exists (select 1 from category c where c.id = sc.category_id)

| category_id |
| ----------: |
|           1 |
|           2 |
|           3 |

-- the delete query
delete from story_category
where not exists (select 1 from category c where c.id = story_category.category_id);

-- outcome
select * from story_category;

| category_id |
| ----------: |
|           4 |
|           5 |

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