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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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The difference between bracket [ ] and double bracket [[ ]] for accessing the elements of a list or
...urn the ith sequential element of x.
For lists, one generally uses [[ to select any single element, whereas [ returns a list of the selected elements.
The [[ form allows only a single element to be selected using integer or character indices, whereas [ allows indexing by vectors. Note though tha...
Colorized Ruby output to the terminal [closed]
...tional:
def no_colors
self.gsub /\e\[\d+m/, ""
end
removes formatting characters
Note
puts "\e[31m" # set format (red foreground)
puts "\e[0m" # clear format
puts "green-#{"red".red}-green".green # will be green-red-normal, because of \e[0
...
Can we write our own iterator in Java?
If I have a list containing [alice, bob, abigail, charlie] and I want to write an iterator such that it iterates over elements that begin with 'a', can I write my own ? How can I do that ?
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Show constraints on tables command
...
Simply query the INFORMATION_SCHEMA:
USE INFORMATION_SCHEMA;
SELECT TABLE_NAME,
COLUMN_NAME,
CONSTRAINT_NAME,
REFERENCED_TABLE_NAME,
REFERENCED_COLUMN_NAME
FROM KEY_COLUMN_USAGE
WHERE TABLE_SCHEMA = "<your_database_name>"
AND TABLE_NAME = "<y...
HTML - Display image after selecting filename [duplicate]
I have a form that allows me with
3 Answers
3
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How do you join on the same table, twice, in mysql?
...
you'd use another join, something along these lines:
SELECT toD.dom_url AS ToURL,
fromD.dom_url AS FromUrl,
rvw.*
FROM reviews AS rvw
LEFT JOIN domain AS toD
ON toD.Dom_ID = rvw.rev_dom_for
LEFT JOIN domain AS fromD
ON fromD.Dom_ID = rvw.rev_dom_from
ED...
Exit single-user mode
...tabase in MULTI_USER mode.
USE master
GO
DECLARE @kill varchar(max) = '';
SELECT @kill = @kill + 'KILL ' + CONVERT(varchar(10), spid) + '; '
FROM master..sysprocesses
WHERE spid > 50 AND dbid = DB_ID('<Your_DB_Name>')
EXEC(@kill);
GO
SET DEADLOCK_PRIORITY HIGH
ALTER DATABASE [<Your_DB...
How to get the index of an element in an IEnumerable?
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extensions with overloads like Select((x, i) => ...) seem to imply that these indexes should exist
– Michael
Mar 19 '14 at 16:05
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How to get .app file of a xcode application
...t-clicking it in the Products directory in the source pane on the left and selecting "Show in Finder".
– Akilan Arasu
Aug 11 '16 at 11:38
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