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In Firebase, is there a way to get the number of children of a node without loading all the node dat
...entire set of data and then counts it client-side, which can be very slow for large amounts of data.
Firebase doesn't currently have a way to count children without loading data, but we do plan to add it.
For now, one solution would be to maintain a counter of the number of children and update it ...
How to format current time using a yyyyMMddHHmmss format?
I'm trying to format the current time using this format yyyyMMddHHmmss .
4 Answers
4
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Shell script to send email [duplicate]
I am on linux machine and I monitor a process usage. Most of the time I will be away from my system and I have access to internet on my device. So I planned to write a shell-script that can mail me the output of the process.
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How do I purge a linux mail box with huge number of emails? [closed]
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You can simply delete the /var/mail/username file to delete all emails for a specific user. Also, emails that are outgoing but have not yet been sent will be stored in /var/spool/mqueue.
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How do Python's any and all functions work?
...rying to understand how the any() and all() Python built-in functions work.
8 Answers
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What's the difference between Cache-Control: max-age=0 and no-cache?
...Control header. One side is where it can be sent by the web server (aka. "origin server"). The other side is where it can be sent by the browser (aka. "user agent").
When sent by the origin server
I believe max-age=0 simply tells caches (and user agents) the response is stale from the get-go a...
What does the `#` operator mean in Scala?
...= new A
a2: A = A@4bed4c8
scala> a2.f(new a1.B)
<console>:11: error: type mismatch;
found : a1.B
required: a2.B
a2.f(new a1.B)
^
When you declare a class inside another class in Scala, you are saying that each instance of that class has such a subclas...
how to check if object already exists in a list
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It depends on the needs of the specific situation. For example, the dictionary approach would be quite good assuming:
The list is relatively stable (not a lot of inserts/deletions, which dictionaries are not optimized for)
The list is quite large (otherwise the overhead of th...
How to change UIPickerView height
...ble to change the height of UIPickerView? Some applications seem to have shorter PickerViews but setting a smaller frame doesn't seem to work and the frame is locked in Interface Builder.
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How to remove focus border (outline) around text/input boxes? (Chrome) [duplicate]
Can anyone explain how to remove the orange or blue border (outline) around text/input boxes? I think it only happens on Chrome to show that the input box is active. Here's the input CSS I'm using:
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