如何编写通用表表达式(CTE)格式的多个表的UPDATE查询? [英] How to write an UPDATE Query for multiple tables in Common Table Expressions (CTE's) format?

问题描述

我如何将以下UPDATE语句重写为通用表表达式(CTE)格式?

Ho do I rewrite the following UPDATE statement into a Common Table Expressions (CTE's) format?

DB::statement('UPDATE taggables, threads SET taggables.created_at = threads.created_at, taggables.updated_at = threads.updated_at WHERE taggables.thread_id = threads.id');

推荐答案

我在这里看不到使用CTE的意义.由于似乎您的目的是从 threads 更新 taggables ，所以我建议您仅使用

I don't really see the point for using a CTE here. Since it seems like your purpose is to update taggables from threads, I would suggest simply using Postgres' update/join syntax, which goes like:

update taggables ta
set created_at = th.created_at, updated_at = th.updated_at
from threads th
where ta.thread_id = th.id

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