RailsTutorial 3.2 Ch 11 - PostgreSQL 语法错误破坏了状态提要 [英] RailsTutorial 3.2 Ch 11 - PostgreSQL syntax error breaks the status feed

问题描述

我在 第 11.3.1 节Rails 教程，并且在此之前所有测试都通过了.之后，主页(包含微博提要)因以下错误而中断:

I'm in Section 11.3.1 of the Rails Tutorial, and all tests were passing prior to this. Afterward, the home page (which has the micropost feed) breaks with this error:

PG::Error: ERROR:  invalid input syntax for integer: "98, 1"
LINE 1: ...CT COUNT(*) FROM "microposts"  WHERE (user_id IN ('98, 1') O...
                                                             ^
: SELECT COUNT(*) FROM "microposts"  WHERE (user_id IN ('98, 1') OR user_id = 101)

并且一些测试因类似问题而失败.这是第一个:

And several of the tests fail with a similar issue. Here's the first one:

1) Authentication authorization as wrong user visiting Users#edit page 
   Failure/Error: before { visit edit_user_path(wrong_user) }
   ActionView::Template::Error:
   PG::Error: ERROR:  invalid input syntax for integer: ""
   LINE 1: ...CT COUNT(*) FROM "microposts"  WHERE (user_id IN ('') OR use...
                                                                ^

现在，我使用的是 PostgreSQL 而不是默认的 SQLite3，所以可能存在语法冲突，但我并不肯定.我对 Postgres 不是很熟悉(只是用它来使 Heroku 部署更干净).

Now, I am using PostgreSQL instead of the default SQLite3, so it may be that there is a syntax conflict, but I'm not positive. I'm not super familiar with Postgres (just using it to make the Heroku deploy cleaner).

看起来主页错误来自使用引号传递给查询的 id - 我进入 psql 来测试一些查询，这是成功的:

It looks like the home page error is coming from the ids being passed to the query with quotes - I went into psql to test a few queries and this is successful:

SELECT "microposts".* FROM "microposts" WHERE "microposts"."id" IN (1,2,3);

虽然失败了:

SELECT "microposts".* FROM "microposts" WHERE "microposts"."id" IN ('1,2,3');

并且规范错误来自正在传递的空数组，相当于这个，它也失败了:

And the spec error is coming from an empty array being passed, equivalent to this, which also fails:

SELECT "microposts".* FROM "microposts" WHERE "microposts"."id" IN ('');

<小时>

熟悉 PostgreSQL 语法的人能告诉我如何重写方法定义来解决这个问题吗?

micropost.rb 中的当前方法如下所示:

The current method in micropost.rb looks like this:

def self.from_users_followed_by(user)
    followed_user_ids = user.followed_user_ids.join(', ')
    where("user_id IN (?) OR user_id = ?", followed_user_ids, user)
end

来自`users.rb'的调用看起来像这样:

And the call from `users.rb' looks like this:

def feed
    Micropost.from_users_followed_by(self)
end

推荐答案

天哪，我自己真的想通了.只需删除方法定义中的连接:

Holy crap, I actually figured this out myself. Just had to remove the join in the method definition:

def self.from_users_followed_by(user)
    followed_user_ids = user.followed_user_ids
    where("user_id IN (?) OR user_id = ?", followed_user_ids, user)
end

user.followed_user_ids.join(', ') 产生这个:"1, 2, 3"

user.followed_user_ids.join(', ') produces this: "1, 2, 3"

同时

user.followed_user_ids 产生这个:1, 2, 3

user.followed_user_ids produces this: 1, 2, 3

这正是我想要的.

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