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MongoDB SELECT COUNT GROUP BY
I am playing around with MongoDB trying to figure out how to do a simple
7 Answers
7
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What is the Difference Between read() and recv() , and Between send() and write()?
...). However, it didn't work when I tried to send binary data that included character 10. write() somewhere inserted character 13 before this. Changing it to send() with a flags parameter of 0 fixed that problem. read() could have the reverse problem if 13-10 are consecutive in the binary data, bu...
Html.DropdownListFor selected value not being set
How can I set the selected value of a Html.DropDownListFor? I've been having a look online and have seen that it can be achieved by using the fourth parameter so like the below:
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How to do SELECT COUNT(*) GROUP BY and ORDER BY in Django?
...lvaro has answered the Django's direct equivalent for GROUP BY statement:
SELECT actor, COUNT(*) AS total
FROM Transaction
GROUP BY actor
is through the use of values() and annotate() methods as follows:
Transaction.objects.values('actor').annotate(total=Count('actor')).order_by()
However ...
What are carriage return, linefeed, and form feed?
What is the meaning of the following control characters:
12 Answers
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How to capitalize the first letter in a String in Ruby
...ия.
If you're using Rails there's an easy workaround:
"мария".mb_chars.capitalize.to_s # requires ActiveSupport::Multibyte
Otherwise, you'll have to install the unicode gem and use it like this:
require 'unicode'
Unicode::capitalize("мария") #=> Мария
Ruby 1.8:
Be sure t...
Can hash tables really be O(1)?
...TW - concrete example - Visual C++'s std::hash of textual keys combines 10 characters evenly spaced along the text into the hash value, so it's O(1) regardless of text length (but massively more collision prone than GCC!). Separately, claims of O(1) have another assumption (normally correctly) that...
Remove duplicates in the list using linq
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var distinctItems = items.GroupBy(x => x.Id).Select(y => y.First());
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How to express a NOT IN query with ActiveRecord/Rails?
...rums, lambda { |forums| { :conditions => ['forum_id not in (?)', forums.select(&:id).join(',')] }
# in your controller
Topic.not_in_forums(@forums)
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Calculating Distance between two Latitude and Longitude GeoCoordinates
...atic double DistanceTo(double lat1, double lon1, double lat2, double lon2, char unit = 'K')
{
double rlat1 = Math.PI*lat1/180;
double rlat2 = Math.PI*lat2/180;
double theta = lon1 - lon2;
double rtheta = Math.PI*theta/180;
double dist =
Math.Sin(rlat1)*Math.Sin(rlat2) + M...