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Retrieve only the queried element in an object array in MongoDB collection
...r to filter an array during projection, which has the benefit of including all matches, instead of just the first one.
db.test.aggregate([
// Get just the docs that contain a shapes element where color is 'red'
{$match: {'shapes.color': 'red'}},
{$project: {
shapes: {$filter: {
...
What does O(log n) mean exactly?
...g that the size of the input affects the growth of the algorithm proportionally...and the same goes for, for example, quadratic time O(n2) etc..even algorithms, such as permutation generators, with O(n!) times, that grow by factorials.
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Drop all tables whose names begin with a certain string
How can I drop all tables whose names begin with a given string?
14 Answers
14
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What does `:_*` (colon underscore star) do in Scala?
...tes: MetaData, scope: NamespaceBinding,
child: Node*)
which is called as
new Elem(prefix, label, attributes, scope,
child1, child2, ... childN)
but here there is only a sequence, not child1, child2, etc. so this allows the result sequence to be used as the input to the constru...
List of special characters for SQL LIKE clause
What is the complete list of all special characters for a SQL (I'm interested in SQL Server but other's would be good too) LIKE clause?
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How to manually set an authenticated user in Spring Security / SpringMVC
After a new user submits a 'New account' form, I want to manually log that user in so they don't have to login on the subsequent page.
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Convert list to dictionary using linq and not worrying about duplicates
...t 2.0 framework at work... @onof Not exactly hard to ignore case. Just add all keys in uppercase.
– Carra
Jul 23 '10 at 14:42
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MongoDB/Mongoose querying at a specific date?
...onents. To query those times you need to create a date range that includes all moments in a day.
db.posts.find( //query today up to tonight
{"created_on": {"$gte": new Date(2012, 7, 14), "$lt": new Date(2012, 7, 15)}})
s...
How do you round a floating point number in Perl?
.... For rounding to a certain number of digits, sprintf() or printf() is usually the easiest
route.
printf("%.3f", 3.1415926535); # prints 3.142
The POSIX module (part of the standard Perl distribution) implements
ceil(), floor(), and a number of other mathematical and trigonometric
func...
How to import module when module name has a '-' dash or hyphen in it?
...appens with sys.modules, you don't need it to import itself), just getting all of the file's globals into your own scope, you can use execfile
# contents of foo-bar.py
baz = 'quux'
>>> execfile('foo-bar.py')
>>> baz
'quux'
>>>
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