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mongo group query how to keep fields
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If you want to keep the information about the first matching entries for each group, you can try aggregating like:
db.test.aggregate({
$group: {
_id : '$name',
name : { $first: '$name' },
age : { $first: '$age' },...
How to create a date and time picker in Android? [closed]
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There is nothing built into Android that offers this.
EDIT: Andriod now offers built-in pickers. Check @Oded answer
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Avoid duplicates in INSERT INTO SELECT query in SQL Server
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Just a clarification on the NOT EXISTS version, you'll need a WITH(HOLDLOCK) hint or no locks will be taken (because there are no rows to lock!) so another thread could insert the row under you.
– IDisposable
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(this == null) in C#!
...t should NOT be possible. You are not allowed to write : base(CheckNull()) if CheckNull is not static, and alike you should not be able to inline an instance-bound lambda.
– quetzalcoatl
Aug 14 '12 at 0:29
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How to base64 encode image in linux bash / shell
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-w 0 this parameter is very important in many cases. Ex. If we are running directly into the command line. Thanks!
– Jayesh Dhandha
Jun 5 '18 at 5:21
4
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Control cannot fall through from one case label
...heck were the C# devs thinking?! It works in every programming language I know, but not in C#.
– Black
Oct 27 '17 at 7:05
8
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How do I check if a number evaluates to infinity?
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if (result == Number.POSITIVE_INFINITY || result == Number.NEGATIVE_INFINITY)
{
// ...
}
You could possibly use the isFinite function instead, depending on how you want to treat NaN. isFinite returns false if your numbe...
Split string into array of character strings
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This answer does now work if you're using Java 8. See stackoverflow.com/a/22718904/1587046
– Alexis C.
Apr 25 '14 at 14:01
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Getting a list of all subdirectories in the current directory
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For anyone concerned about performance differences between os.walk and os.listdir+os.path.isdir solutions: I just tested on a directory with 10,000 subdirectories (with millions of files in the hierarchy below) and the performance differences are negligible. os.wal...