使用MySQL左连接删除行

I have two tables, one for job deadlines, one for describe a job. Each job can take a status and some statuses means the jobs' deadlines must be deleted from the other table.

我有两个表格，一个是工作截止日期，一个是描述工作。每个作业都有一个状态，一些状态意味着必须从另一个表中删除作业的截止日期。

I can easily SELECT the jobs/deadlines that meets my criteria with a LEFT JOIN:

我可以很容易地选择符合我的标准的工作/截止日期。

SELECT * FROM `deadline`
LEFT JOIN `job` ON deadline.job_id = job.job_id
WHERE `status` = 'szamlazva'
OR `status` = 'szamlazhato'
OR `status` = 'fizetve'
OR `status` = 'szallitva'
OR `status` = 'storno'

(status belongs to job table not deadline)

(状态属于工作表而非截止日期)

But when I'd like to delete these rows from deadline, MySQL throws an error. My query is:

但是当我想从deadline删除这些行时，MySQL会抛出一个错误。我查询的方法是:

DELETE FROM `deadline`
LEFT JOIN `job`
ON deadline.job_id = job.job_id
WHERE `status` = 'szamlazva'
OR `status` = 'szamlazhato'
OR `status` = 'fizetve'
OR `status` = 'szallitva'
OR `status` = 'storno'

MySQL error says nothing:

MySQL错误说什么:

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'LEFT JOIN job ON deadline.job_id = job.job_id WHERE status = 'szaml' at line 1

您的SQL语法有错误;请检查与MySQL服务器版本对应的手册，以便在“截止日期”附近使用“左侧连接作业”。job_id =工作。job_id，其中第1行状态= 'szaml'

How can I turn my SELECT into a working DELETE query?

如何将SELECT转换为可工作的删除查询?

3 个解决方案

#1

268

You simply need to specify on which tables to apply the DELETE.

您只需指定要应用DELETE的表。

Delete only the deadline rows:

只删除截止日期行:

DELETE `deadline` FROM `deadline` LEFT JOIN `job` ....

Delete the deadline and job rows:

删除截止日期和工作行:

DELETE `deadline`, `job` FROM `deadline` LEFT JOIN `job` ....

Delete only the job rows:

只删除作业行:

DELETE `job` FROM `deadline` LEFT JOIN `job` ....

#2

If you are using "table as", then specify it to delete.

如果使用的是“表as”，则指定要删除它。

In the example i delete all table_1 rows which are do not exists in table_2.

在本例中，我删除了表_2中不存在的所有表_1行。

DELETE t1 FROM `table_1` t1 LEFT JOIN `table_2` t2 ON t1.`id` = t2.`id` WHERE t2.`id` IS NULL

#3

DELETE FROM deadline where ID IN (
    SELECT d.ID FROM `deadline` d LEFT JOIN `job` ON deadline.job_id = job.job_id WHERE `status` =  'szamlazva' OR `status` = 'szamlazhato' OR `status` = 'fizetve' OR `status` = 'szallitva' OR `status` = 'storno');

I am not sure if that kind of sub query works in MySQL, but try it. I am assuming you have an ID column in your deadline table.

我不确定这种子查询在MySQL中是否有效，但请尝试一下。我假设你在截止日期表中有一个ID列。

#1

268