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SQL JOIN and different types of JOINs
...or the pictures. See A visualization of SQL joins by Jeff Atwood (yes, the one who co-authored SO) and the linked article by Ligaya Turmelle where Jeff got the idea and explanded it.
– ypercubeᵀᴹ
Oct 12 '14 at 11:29
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MySQL Query GROUP BY day / month / year
...I knew this earlier...so many lines of PHP to do something mysql can do in one line.
– nights
Nov 1 '18 at 3:01
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Should functions return null or an empty object?
...ctions. Is it better to return a Null or an empty object? And why should one do one over the other?
31 Answers
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What is the difference between bottom-up and top-down?
... very rare cases*). This is like memoization but more active, and involves one additional step: You must pick, ahead of time, the exact order in which you will do your computations. This should not imply that the order must be static, but that you have much more flexibility than memoization.
examp...
Proper REST response for empty table?
...very confused as an author of a client for your application if I got a 200 one day and a 404 the next day just because someone happened to remove a couple of users. What am I supposed to do? Is my URL wrong? Did someone change the API and neglect to leave a redirection.
Why not 204 (No Content) ?
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How to remove all white spaces in java [duplicate]
...and removes all the white space within that line.
the line can consist of one word or more.
14 Answers
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How do you serialize a model instance in Django?
...is your model instance
dict_obj = model_to_dict( obj )
You now just need one straight json.dumps call to serialize it to json:
import json
serialized = json.dumps(dict_obj)
That's it! :)
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How do I create a transparent Activity on Android?
...he following style in your res/values/styles.xml file (if you don’t have one, create it.) Here’s a complete file:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<style name="Theme.Transparent" parent="android:Theme">
<item name="android:windowIsTranslucent">tru...
Why java.util.Optional is not Serializable, how to serialize the object with such fields
...bda (JSR-335) expert group considered and rejected it. That note, and this one and this one indicate that the primary design goal for Optional is to be used as the return value of functions when a return value might be absent. The intent is that the caller immediately check the Optional and extract ...
How can I clear an HTML file input with JavaScript?
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How about removing that node, creating a new one with the same name?
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