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mongodb: insert if not exists
...a conflicting save. Consider the following done using the mongodb shell:
> db.getCollection("test").insert ({a:1, b:2, c:3})
> db.getCollection("test").find()
{ "_id" : ObjectId("50c8e35adde18a44f284e7ac"), "a" : 1, "b" : 2, "c" : 3 }
> db.getCollection("test").ensureIndex ({"a" : 1}, {uni...
What is 'Currying'?
...oes, though that's irrelevant thanks to currying; e.g. div :: Integral a => a -> a -> a -- note those multiple arrows? "Map a to function mapping a to a" is one reading;-). You could use a (single) tuple argument for div &c, but that would be really anti-idiomatic in Haskell.
...
How do you enable “Enable .NET Framework source stepping”?
...b/2604121, so KB2604121, is what we're interested in.
Go to Control Panel->Programs and Features, and click "View Installed Updates"
Find an update which lists the KB number (you can use the search in the upper right box).
Uninstall that update.
Repeat this process for this same dll until the dll...
How to set up Android emulator proxy settings
...
On Run Configuration> Android Application > App > Target > Additional Emulator Command Line Options: -http-proxy http://xx.xxx.xx.xx:8080
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What is a serialVersionUID and why should I use it?
...u can tell Eclipse to ignore these serialVersionUID warnings:
Window > Preferences > Java > Compiler > Errors / Warnings > Potential Programming Problems
In case you didn't know, there are a lot of other warnings you can enable in this section (or even have some reported as err...
Printing the last column of a line in a file
...all lines containing A1
awk '/A1/ {print $NF}' file
Thanks to @MitchellTracy's comment, tail might miss the record containing A1 and thus you get no output at all. This may be solved by switching tail and awk, searching first through the file and only then show the last line:
awk '/A1/ {print ...
send mail from linux terminal in one line [closed]
...
You can also use sendmail:
/usr/sbin/sendmail user@domain.com < /file/to/send
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How do I remove all specific characters at the end of a string in PHP?
...-_ ]+$/"; is applied to string
$string = "Some text........"; // $resul -> "Some text";
$string = "Some text.????"; // $resul -> "Some text";
$string = "Some text!!!"; // $resul -> "Some text";
$string = "Some text..!???"; // $resul -> "Some text";
I hope it is helpful for y...
Breadth First Vs Depth First
... the payload Node
Foreach child of Node
ProcessNode(child)
/* Alternate time to work on the payload Node (see below) */
The recursion ends when you reach a node that has no children, so it is guaranteed to end for
finite, acyclic graphs.
At this point, I've still cheated a little. W...
How can I do SELECT UNIQUE with LINQ?
... == true
select dbo.Color.Name).Distinct().OrderBy(name=>name);
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