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SQL Server indexes - ascending or descending, what difference does it make?
...ces to rows.
Since the table is clustered, the references to rows are actually the values of the pk. They are also ordered within each value of col1.
This means that that leaves of the index are actually ordered on (col1, pk), and this query:
SELECT col1, pk
FROM mytable
ORDER BY
col1...
Run a single migration file
...f the ruby file:
rails console
>> require "db/migrate/20090408054532_add_foos.rb"
>> AddFoos.up
Note: newer versions of rails may require AddFoos.new.up rather than AddFoos.up.
An alternative way (without IRB) which relies on the fact that require returns an array of class names:
sc...
How do you know when to use fold-left and when to use fold-right?
...ee it. It's "haskell-style pseudocode". :)
– laughing_man
Apr 21 '15 at 2:38
...
Format a datetime into a string with milliseconds
...
Useful with timezone too: date = datetime(2019,5,10) date_with_tz = pytz.timezone('Europe/Rome').localize(date) date_with_tz.isoformat(sep='T', timespec='milliseconds') output: '2019-05-10T00:00:00.000+02:00'
– Ena
May 10 '19 at 9:17
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How can I add an item to a SelectList in ASP.net MVC
Basically I am looking to insert an item at the beginning of a SelectList with the default value of 0 and the Text Value of " -- Select One --"
...
How to list the tables in a SQLite database file that was opened with ATTACH?
....schema tablename
Print the entire table:
SELECT * FROM tablename;
List all of the available SQLite prompt commands:
.help
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How to export collection to CSV in MongoDB?
How do you export all the records in a MongoDB collection to a .csv file?
11 Answers
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Javascript when to use prototypes
...{ ... },
css: function() { ... },
animate: function() { ... },
// etc...
};
But that would mean that every jQuery object in memory would have dozens of named slots containing the same methods, over and over.
Instead, those methods are defined on a prototype and all jQuery objects "inheri...
Passport.js - Error: failed to serialize user into session
...d serializing user information but only id's (for bloat/perf reasons personally).
– electblake
Jan 22 '16 at 20:03
2
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Allowed characters in filename [closed]
Where can I find a list of allowed characters in filenames, depending on the operating system?
(e.g. on Linux, the character : is allowed in filenames, but not on Windows)
...