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How to determine if a record is just created or updated in after_save
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I was looking to use this for an after_save callback.
A simpler solution is to use id_changed? (since it won't change on update) or even created_at_changed? if timestamp columns are present.
Update: As @mitsy points out, if this check is needed outside of callbacks th...
Rails: select unique values from a column
I already have a working solution, but I would really like to know why this doesn't work:
12 Answers
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Does Haskell require a garbage collector?
... the user types "clear"; so the lifetime of this must be determined dynamically, and this is why dynamic memory management is necessary.
So in this sense, automated dynamic memory allocation is necessary, and in practice this means: yes, Haskell requires a garbage collector, since garbage collectio...
How to configure Eclipse build path to use Maven dependencies?
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It was actually enabled already for my project. Maybe because I chose to add a POM file to an existing project? However doing Maven > Update project configuration seems to have fixed it for me. Also it was your answer that eventually...
How do I add a bullet symbol in TextView?
...st to clarify: use setText("\u2022 Bullet"); to add the bullet programmatically. 0x2022 = 8226
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Rename column SQL Server 2008
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You are allowed and encouraged to put brackets in the first parameter, identifying the column, but not in the second parameter. Like this: EXEC sp_RENAME '[TableName].[OldColumnName]', 'NewColumnName', 'COLUMN'
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Why am I not getting a java.util.ConcurrentModificationException in this example?
... iterator and listIterator
methods are fail-fast: if the list is structurally modified at any
time after the iterator is created, in any way except through the
iterator's own remove or add methods, the iterator will throw a
ConcurrentModificationException.
This check is done in the next() ...
How can I remove the string “\n” from within a Ruby string?
... your gsub. The different quote marks behave differently.
Double quotes " allow character expansion and expression interpolation ie. they let you use escaped control chars like \n to represent their true value, in this case, newline, and allow the use of #{expression} so you can weave variables and...
How is Node.js inherently faster when it still relies on Threads internally?
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There are actually a few different things being conflated here. But it starts with the meme that threads are just really hard. So if they're hard, you are more likely, when using threads to 1) break due to bugs and 2) not use them as eff...
Click event doesn't work on dynamically generated elements [duplicate]
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The click() binding you're using is called a "direct" binding which will only attach the handler to elements that already exist. It won't get bound to elements created in the future. To do that, you'll have to create a "delegated" binding by using on().
Del...