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Numpy `logical_or` for more than two arguments
...or function takes no more than two arrays to compare. How can I find the union of more than two arrays? (The same question could be asked with regard to Numpy's logical_and and obtaining the intersection of more than two arrays.)
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Why does Java's hashCode() in String use 31 as a multiplier?
...odrich and Tamassia computed from over 50,000 English words (formed as the union of the word lists provided in two variants of Unix) that using the constants 31, 33, 37, 39, and 41 will produce fewer than 7 collisions in each case. This may be the reason that so many Java implementations choose such...
ORDER BY the IN value list
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Just because it is so difficult to find and it has to be spread: in mySQL this can be done much simpler, but I don't know if it works in other SQL.
SELECT * FROM `comments`
WHERE `comments`.`id` IN ('12','5','3','17')
ORDER BY FIELD(`comments`.`id`,'12','5','3','17')
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How do you write multiline strings in Go?
...DanieleD That's a slight nonsequitur, but which dialect? Presumably mainly MySQL? stackoverflow.com/a/10574031 Note that by extension of the same argument, it's a pain for embedding markdown, or shell scripts (if you opt to use backtick in place of $(abcd)).
– Ivan Vučica
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Finding duplicate values in a SQL table
...QL Server 2017) still requires all non-aggregated columns in the GROUP BY.
MySQL is unpredictable and you need sql_mode=only_full_group_by:
GROUP BY lname ORDER BY showing wrong results;
Which is the least expensive aggregate function in the absence of ANY() (see comments in accepted answer).
Ora...
How is null + true a string?
...for the operation operator op(x, y) is determined. The set consists of the union of the candidate operators provided by X and the candidate operators provided by Y, each determined using the rules of §7.3.5. If X and Y are the same type, or if X and Y are derived from a common base type, then share...
How do you attach and detach from Docker's process?
...l+p + Ctrl+q to quit the container:
# docker exec -it 91262536f7c9 bash
root@91262536f7c9:/# ps -aux
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
root 1 0.0 0.0 18160 1908 ? Ss+ 04:03 0:00 /bin/bash
root 15 0.0 0.0 18164 1892 ? S...
How do I create a crontab through a script
...moving existing crontab entries and also I needed to use a different user (root) so I used the following to maintain the existing entries: echo -e "$(sudo crontab -u root -l)\n* * * * * echo hello > /home/danny/temp.log 2>&1" | sudo crontab -u root - Hopefully this helps someone
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Problems with contenttypes when loading a fixture in Django
I am having trouble loading Django fixtures into my MySQL database because of contenttypes conflicts. First I tried dumping the data from only my app like this:
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How to insert element into arrays at specific position?
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array_slice() can be used to extract parts of the array, and the union array operator (+) can recombine the parts.
$res = array_slice($array, 0, 3, true) +
array("my_key" => "my_value") +
array_slice($array, 3, count($array)-3, true);
This example:
$array = array(
'zero' ...