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Computed / calculated / virtual / derived columns in PostgreSQL
...s defined in the SQL standard and implemented by some RDBMS including DB2, MySQL and Oracle. Nor the similar "computed columns" of SQL Server.
STORED generated columns are introduced with Postgres 12. Trivial example:
CREATE TABLE tbl (
int1 int
, int2 int
, product bigint GENERATED ALWAYS...
SQL - Update multiple records in one query
...
This is a MySQL solution, not Postgres or MSSQL.
– Rz Mk
Dec 23 '17 at 15:30
1
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How to change Rails 3 server default port in develoment?
...matically be run when you run "rails" with Rails 3 gems installed from the root of your application.
APP_PATH = File.expand_path('../../config/application', __FILE__)
require File.expand_path('../../config/boot', __FILE__)
# THIS IS NEW:
require "rails/commands/server"
module Rails
class Serve...
IntelliJ does not show project folders
...hat pops up, click on the "..." next button which takes you to the Content root. Find your root folder and select it
Click the "ok" button
Ignore any warning that says the name is already in use
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Convert Base64 string to an image file? [duplicate]
...m.php-
'public_feeds' => [
'driver' => 'local',
'root' => public_path() . '/uploads/feeds',
],
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How to filter SQL results in a has-many-through relation
...on easier to extend to n clubs and that avoids INTERSECT (not available in MySQL) and IN (as performance of this sucks in MySQL)
SELECT s.id,
s.name
FROM student s
join student_club sc
ON s.id = sc.student_id
WHERE sc.club_id IN ( 30, 50 )
GROUP BY s.id,
s.name
...
Count how many files in directory PHP
...nything to /path/to/dir would fail it, because first / means starting from root dir. If there were path/to/dir, then yes, __DIR__ . '/path/to/dir' would help (in this case you must use / after __DIR__
– Justinas
Feb 22 '19 at 14:30
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Get OS-level system information
... Runtime.getRuntime().totalMemory());
/* Get a list of all filesystem roots on this system */
File[] roots = File.listRoots();
/* For each filesystem root, print some info */
for (File root : roots) {
System.out.println("File system root: " + root.getAbsolutePath());
Sy...
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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Should I use px or rem value units in my CSS? [closed]
... <div> - 1.25px
The CSS3 rem, which is always relative only to the root html element, is now supported on 96% of all browsers in use.
The Opinion
I think everyone agrees that it's good to design your pages to be accommodating to everyone, and to make consideration for the visually impaire...