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SQLite table constraint - unique on multiple columns
...'Charles', 'chucky cheese'),
('Alice', 'Some other title');
$ sqlite3 test.sqlite
SQLite version 3.28.0 2019-04-16 19:49:53
Enter ".help" for usage hints.
sqlite> CREATE TABLE IF NOT EXISTS t1 (id INTEGER PRIMARY KEY, a TEXT UNIQUE, b TEXT);
sqlite> INSERT INTO t1 (a, b) VALUES
...>...
Rails auto-assigning id that already exists
...ossible your database has an improper identity seed on your id column? To test try doing a couple inserts directly into your database and see if the same behavior exists.
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Firing a double click event from a WPF ListView item using MVVM
...s, etc.) from the logic part (workflow). Furthermore, you are able to unit test the logic part.
I know enough scenarios where you have to write code behind because data binding is not a solution to everything. In your scenario I would handle the DoubleClick event in the code behind file and delegat...
How do I get the entity that represents the current user in Symfony2?
...Symfony 4+, 2019+ Approach
In symfony 4 (probably 3.3 also, but only real-tested in 4) you can inject the Security service via auto-wiring in the controller like this:
<?php
use Symfony\Component\Security\Core\Security;
class SomeClass
{
/**
* @var Security
*/
private $secur...
image.onload event and browser cache
...nction () {
alert("image is loaded");
}
img.src = "img.jpg";
Fiddle - tested on latest Firefox and Chrome releases.
You can also use the answer in this post, which I adapted for a single dynamically generated image:
var img = new Image();
// 'load' event
$(img).on('load', function() {
alert...
How to convert floats to human-readable fractions?
...he function would perform at most log(27) ~= 4 3/4 comparisons. Here is a tested C version of the code
char *userTextForDouble(double d, char *rval)
{
if (d == 0.0)
return "0";
// TODO: negative numbers:if (d < 0.0)...
if (d >= 1.0)
sprintf(rval, "%.0f ", floor(d...
What's the difference between echo, print, and print_r in PHP?
...t know exactly what values/types you have in your variables. Consider this test program:
$values = array(0, 0.0, false, '');
var_dump($values);
print_r ($values);
With print_r you can't tell the difference between 0 and 0.0, or false and '':
array(4) {
[0]=>
int(0)
[1]=>
float(0)
...
PHP cURL vs file_get_contents
...
This is old topic but on my last test on one my API, cURL is faster and more stable. Sometimes file_get_contents on larger request need over 5 seconds when cURL need only from 1.4 to 1.9 seconds what is double faster.
I need to add one note on this that I ju...
Show a PDF files in users browser via PHP/Perl
...ublic');
ini_set('zlib.output_compression','0');
die($content);
Tested and works fine. If you want the file to download instead, replace
Content-Disposition: inline
with
Content-Disposition: attachment
...
Is there a way to create your own html tag in HTML5?
... agree, writing your own tags is not for the faint of heart. Make sure you test it thoroughly. I would like to say one thing though... don't write CSS for IE6. Completely waste of resources and enables further use of such a horrible product that not even Microsoft endorses.
– T...