blocks|key|162113|text|希望这就是你要找的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|162114|https://stackoverflow.com/a/6587546/2238259|offset|length|162115|对于您的第二个问题，我怀疑最好检查何时需要进行此计算，最好是在网络流量处于低谷的特定时间批量处理。|162116|编辑:+Woops。我实际上找到了两个链接，但显然第一个链接丢失了。希望你能把它修好。|162117|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|17|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|R|8|@]|9|@$D|S|E|T|1|U]]|A|$]]|$1|F|3|G|5|6|7|V|8|@]|9|@]|A|$]]|$1|H|3|I|5|6|7|W|8|@]|9|@]|A|$]]|$1|J|3|-4|5|6|7|X|8|@]|9|@]|A|$]]]|K|$L|$5|M|N|O|A|$P|C]]]]

hopefully this is what you're looking for.

<a href="https://stackoverflow.com/a/6587546/2238259">https://stackoverflow.com/a/6587546/2238259</a>

For your second issue, I suspect it would be better to inspect when this calculation needs to happen, it would be best if it could be handled in batch at a specified time where network traffic is at its trough.

EDIT: Woops. I actually found 2 links but lost the first one, apparently. Hopefully you have it fixed.

blocks|key|164500|text|要禁用整体回调，请使用...|type|unstyled|depth|inlineStyleRanges|entityRanges|data|164501|Survey.skip_callback(:save,+:before,+:calculate_averages)|code-block|syntax|javascript|164502|然后启用它们..。|164503|Survey.set_callback(:save,+:before,+:calculate_average)|164504|这将跳过/设置所有实例。|164505|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

To disable en-mass callbacks use...

<pre><code>Survey.skip_callback(:save, :before, :calculate_averages)
</code></pre>

Then to enable them...

<pre><code>Survey.set_callback(:save, :before, :calculate_average)
</code></pre>

This skips/sets for all instances.

blocks|key|2758295|text|update_column是一个ActiveRecord函数，它不运行任何回调，也不运行验证。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2758296|entityMap^0|0|D|G|C|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|M|8|@]|D|@]|E|$]]]|G|$]]

<code>update_column</code> is an <code>ActiveRecord</code> function which does not run any callbacks, and it also does not run validation.

blocks|key|163355|text|我相信你所要求的可以通过ActiveSupport::Callbacks来实现。看看set_callback和skip_callback吧。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|163356|为了“强制调用回调，即使你没有对记录做任何更改”，你需要将回调注册到某个事件，例如save,+validate+etc.。|163357|set_callback+:save,+:before,+:my_before_save_callback|code-block|syntax|javascript|163358|要跳过before_save回调，您可以执行以下操作：|163359|Survey.skip_callback(:save,+:before,+:calculate_average).+|163360|请在其他支持的选项上引用链接的ActiveSupport::Callbacks，例如set_callback和skip_callback的条件和块。|163361|entityMap|0|LINK|mutability|MUTABLE|url|http://api.rubyonrails.org/classes/ActiveSupport/Callbacks/ClassMethods.html|1^0|C|O|16|C|1J|D|C|O|0|0|15|J|0|0|3|B|0|0|F|O|16|C|1J|D|F|O|1|0^^$0|@$1|2|3|4|5|6|7|11|8|@$9|12|A|13|B|C]|$9|14|A|15|B|C]|$9|16|A|17|B|C]]|D|@$9|18|A|19|1|1A]]|E|$]]|$1|F|3|G|5|6|7|1B|8|@$9|1C|A|1D|B|C]]|D|@]|E|$]]|$1|H|3|I|5|J|7|1E|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|1F|8|@$9|1G|A|1H|B|C]]|D|@]|E|$]]|$1|O|3|P|5|J|7|1I|8|@]|D|@]|E|$K|L]]|$1|Q|3|R|5|6|7|1J|8|@$9|1K|A|1L|B|C]|$9|1M|A|1N|B|C]|$9|1O|A|1P|B|C]]|D|@$9|1Q|A|1R|1|1S]]|E|$]]|$1|S|3|-4|5|6|7|1T|8|@]|D|@]|E|$]]]|T|$U|$5|V|W|X|E|$Y|Z]]|10|$5|V|W|X|E|$Y|Z]]]]

I believe what you are asking for can be achieved with <a href="http://api.rubyonrails.org/classes/ActiveSupport/Callbacks/ClassMethods.html"><code>ActiveSupport::Callbacks</code></a>. Have a look at <code>set_callback</code> and <code>skip_callback</code>. 

In order to "force callbacks to get called even if you made no changes to the record", you need to register the callback to some event e.g. <code>save, validate etc.</code>. 

<pre><code>set_callback :save, :before, :my_before_save_callback
</code></pre>

To skip the <code>before_save</code> callback, you would do: 

<pre><code>Survey.skip_callback(:save, :before, :calculate_average). 
</code></pre>

Please reference the linked <a href="http://api.rubyonrails.org/classes/ActiveSupport/Callbacks/ClassMethods.html"><code>ActiveSupport::Callbacks</code></a> on other supported options such as conditions and blocks to <code>set_callback</code> and <code>skip_callback</code>.

blocks|key|166092|text|对于Rails3，ActiveSupport::Callbacks为您提供了必要的控制。您可以整体禁用，或使用skip_callback明智地禁用，如下所示：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|166093|Vote.skip_callback(:save,+:after,+:add_points_to_user)|code-block|syntax|javascript|166094|…之后，您可以在禁止:add_points_to_user的情况下对投票实例进行操作|166095|entityMap^0|9|O|1J|D|0|0|A|J|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]|$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@]|E|$]]|$1|M|3|-4|5|6|7|X|8|@]|D|@]|E|$]]]|N|$]]

For Rails 3 <code>ActiveSupport::Callbacks</code> gives you the necessary control. You can <code>reset_callbacks</code> en-masse, or use <code>skip_callback</code> to disable judiciously like this:

<pre><code>Vote.skip_callback(:save, :after, :add_points_to_user)
</code></pre>

&hellip;after which you can operate on Vote instances with <code>:add_points_to_user</code> inhibited

blocks|key|164535|text|如果要在检查每个调查后有条件地跳过回调，可以编写自定义方法。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|164536|对于ex。|164537|修改后的回调|offset|length|style|BOLD|164538|before_save+:calculate_averages,+if:+Proc.new{+%7Csurvey%7C+!survey.skip_callback+}|code-block|syntax|javascript|164539|新实例方法|164540|def+skip_callback(value+=+false)
++@skip_callback+=+@skip_callback+?+@skip_callback+:+value
end|164541|用于更新调查的脚本|164542|Survey.all.each+do+%7Csurvey%7C
++survey.some_average+=+(survey.some_value+%2B+survey.some_other_value)+/+2.to_f
++#and+some+more+averages...
++survey.skip_callback(true)
++survey.save!
end|164543|这是一种破解，但希望会为你工作。|164544|entityMap^0|0|0|0|6|0|0|0|5|0|0|7|2|0|0|0|G|0^^$0|@$1|2|3|4|5|6|7|10|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|11|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|12|8|@$F|13|G|14|H|I]]|9|@]|A|$]]|$1|J|3|K|5|L|7|15|8|@]|9|@]|A|$M|N]]|$1|O|3|P|5|6|7|16|8|@$F|17|G|18|H|I]]|9|@]|A|$]]|$1|Q|3|R|5|L|7|19|8|@]|9|@]|A|$M|N]]|$1|S|3|T|5|6|7|1A|8|@$F|1B|G|1C|H|I]]|9|@]|A|$]]|$1|U|3|V|5|L|7|1D|8|@]|9|@]|A|$M|N]]|$1|W|3|X|5|6|7|1E|8|@$F|1F|G|1G|H|I]]|9|@]|A|$]]|$1|Y|3|-4|5|6|7|1H|8|@]|9|@]|A|$]]]|Z|$]]

If you want to conditionally skip callbacks after checking for each survey you can write your custom method.

For ex.

Modified callback

<pre class="lang-rb prettyprint-override"><code>before_save :calculate_averages, if: Proc.new{ |survey| !survey.skip_callback }
</code></pre>

New instance method

<pre class="lang-rb prettyprint-override"><code>def skip_callback(value = false)
 @skip_callback = @skip_callback ? @skip_callback : value
end
</code></pre>

Script to update surveys

<pre class="lang-rb prettyprint-override"><code>Survey.all.each do |survey|
 survey.some_average = (survey.some_value + survey.some_other_value) / 2.to_f
 #and some more averages...
 survey.skip_callback(true)
 survey.save!
end
</code></pre>

Its kinda hack but hope will work for you.

blocks|key|2971181|text|不适用于Rails+5|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2971182|Survey.skip_callback(:save,+:before,+:calculate_average)+|code-block|syntax|javascript|2971183|适用于Rails+5|2971184|Survey.skip_callback(:save,+:before,+:calculate_average,+raise:+false)|2971185|https://github.com/thoughtbot/factory_bot/issues/931|offset|length|2971186|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|0|0|0|1G|0|0^^$0|@$1|2|3|4|5|6|7|V|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|W|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|X|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|Y|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|Z|8|@]|9|@$M|10|N|11|1|12]]|A|$]]|$1|O|3|-4|5|6|7|13|8|@]|9|@]|A|$]]]|P|$Q|$5|R|S|T|A|$U|L]]]]

Doesn't work for Rails 5

<pre><code>Survey.skip_callback(:save, :before, :calculate_average) 
</code></pre>

Works for Rails 5

<pre><code>Survey.skip_callback(:save, :before, :calculate_average, raise: false)
</code></pre>

<a href="https://github.com/thoughtbot/factory_bot/issues/931" rel="noreferrer">https://github.com/thoughtbot/factory_bot/issues/931</a>

blocks|key|164554|text|Rails+5.2.3要求一个事后派对脚本不触发模型事件，update_column(column_name，value)做到了这一点：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|164555|task.update_column(task_status,+ReferenceDatum::KEY_COMPLETED)|code-block|syntax|javascript|164556|https://apidock.com/rails/ActiveRecord/Persistence/update_column|offset|length|164557|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|0|1S|0|0^^$0|@$1|2|3|4|5|6|7|R|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|S|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|T|8|@]|9|@$I|U|J|V|1|W]]|A|$]]|$1|K|3|-4|5|6|7|X|8|@]|9|@]|A|$]]]|L|$M|$5|N|O|P|A|$Q|H]]]]

Rails 5.2.3 requiring an after party script to NOT trigger model events, update_column(column_name, value) did the trick:

<pre><code>task.update_column(task_status, ReferenceDatum::KEY_COMPLETED)
</code></pre>

<a href="https://apidock.com/rails/ActiveRecord/Persistence/update_column" rel="nofollow noreferrer">https://apidock.com/rails/ActiveRecord/Persistence/update_column</a>

I need to calculate values when saving a model in Rails. So I call <code>calculate_averages</code> as a callback for a <code>Survey</code> class:

<pre><code>before_save :calculate_averages
</code></pre>

However, occasionally (and initially I have 10k records that need this operation) I need to manually update all the averages for every record. No problem, I have code like the following:

<pre><code>Survey.all.each do |survey|
 survey.some_average = (survey.some_value + survey.some_other_value) / 2.to_f
 #and some more averages...
 survey.save!
end
</code></pre>

Before even running this code, I'm worried the <code>calculate_averages</code> is going to get called and duplicate this and probably even cause some problems with the way I'm doing things. Ok, so then I think, well I'll just do nothing and let <code>calculate_averages</code> get called and do its thing. Problem there is, first, is there a way to force callbacks to get called even if you made no changes to the record?

Secondly, the way averages are calculated it's far more efficient to simply not let the callbacks get called at all and do the averages for everything all at once. Is this possible to not let callbacks get called?

How to save a model without running callbacks in Rails

在Rails中保存模型时，我需要计算值。因此，我调用calculate_averages作为Survey类的回调：before_save :calculate_averages但是，偶尔(最初我有10k条记录需要此操作)，我需要手动更新每条记录的所有平均值。没问题，我有如下代码：Survey.all.each do |...

问如何在不运行Rails回调的情况下保存模型
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