如何使用加入从选择中更新

问题描述

如何更新子查询中也存在的表?我必须分2个阶段完成吗?(创建一个临时表 - 将选定的数据放入其中，然后更新最终表)

How can I update a table that is also present in a subquery? Do I have to do it in 2 stages? (create a temporary table - put the selected data in it and then update the final table)

我正在尝试使用每个 CTN 的网络标签更新 invoiceLine 表.

I am trying to update the invoiceLine table with the label of the network for each CTN.

最终结果是:

• 发票行

ctn       network
1234      network1
2345      network2
3456      network1

我有以下表格:

• 发票行

ctn       network
1234      null
2345      null
3456      null

终端

terminal

ctn       network
1234      1
2345      2
3456      1

网络

network

id        label
1         network1
2         network2

我可以运行一个选择，但我不确定如何使用连接进行更新:

I can run a select but I'm not sure how to update with a join:

update invoiceLine
inner join terminal on terminal.ctn = invoiceLine.ctn
set invoiceLine.network =
(
  select network.label
  from invoiceLine
  inner join terminal on terminal.ctn = invoiceLine.ctn
  inner join network on network.id = terminal.network
)
where invoiceLine.ctn = terminal.ctn

但是 MySQL 抛出了一个

but MySQL throws a

错误代码:1093.您不能在 FROM 子句中指定目标表 'invoiceLine' 进行更新

推荐答案

UPDATE invoiceLine
    INNER JOIN terminal
        ON invoiceLine.ctn = terminal.ctn
    INNER JOIN network
        ON terminal.network = network.id
    SET invoiceLine.network = network.label

这篇关于如何使用加入从选择中更新的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！