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Query a parameter (postgresql.conf setting) like “max_connections”
... SHOW, such as minimum
and maximum values.
For your original request:
SELECT *
FROM pg_settings
WHERE name = 'max_connections';
Finally, there is current_setting(), which can be nested in DML statements:
SELECT current_setting('max_connections');
Related:
How to test my ad-hoc SQL wit...
What is the coolest thing you can do in
...sponse from my kids with a quick VB script to manipulate a Microsoft Agent character. For those that aren't familiar with MS Agent, it's a series of animated onscreen characters that can be manipulated via a COM interface. You can download the code and characters at the Microsoft Agent download page...
Is there a standard for storing normalized phone numbers in a database?
...
A good old nvarchar(42) with a bit of validation /^+?[0-9 -\.\(\)#*]{4,41}$/ works very well!
– SandRock
Apr 5 '12 at 20:19
...
Disable validation of HTML5 form elements
...ecause it should absolutely work without JavaScript.
In my case, I put a select element with 2 options (http:// or https://) before the URL input because I just need websites (and no ftp:// or other things). This way I avoid typing this weird prefix (the biggest regret of Tim Berners-Lee and maybe...
How to check command line parameter in “.bat” file?
...tax of the command is incorrect.
But what do I get, when the number of "-characters "matches" (i.e. - is even), in such a case:
D:\>args bla2" "bla3
bla2" "bla3
Done.
NICE - I hope you learned something about how .bat files split their command line arguments (HINT: *It's not exactly like in ...
pandas GroupBy columns with NaN (missing) values
...s far result in potentially dangerous behavior as it is quite possible you select a dummy value that is actually part of the dataset. This is increasingly likely as you create groups with many attributes. Simply put, the approach doesn't always generalize well.
A less hacky solve is to use pd.drop_...
Django: How do I add arbitrary html attributes to input fields on a form?
...$list.each(function () {
$(this).addClass('form-control')
});
var $select = $("#django_form select");
$select.each(function () {
$(this).addClass('custom-select w-90')
});
var $list = $("#django_form :input[type='number']");
$list.each(function () {
$(this).addClass('form-con...
Check if full path given
...ted(path)
&& !Path.GetPathRoot(path).Equals(Path.DirectorySeparatorChar.ToString(), StringComparison.Ordinal)
The above condition:
does not require file system permissions
returns false in most cases where the format of path is invalid (rather than throwing an exception)
returns true onl...
Efficient paging in SQLite with millions of records
...red field(s), and continue just after them when displaying the next page:
SELECT *
FROM MyTable
WHERE SomeColumn > LastValue
ORDER BY SomeColumn
LIMIT 100;
(This is explained with more detail on the SQLite wiki.)
When you have multiple sort columns (and SQLite 3.15 or later), you can use a ro...
Where do “pure virtual function call” crashes come from?
...asily optimized away):
#include <iostream>
using namespace std;
char pool[256];
struct Base
{
virtual void foo() = 0;
virtual ~Base(){};
};
struct Derived: public Base
{
virtual void foo() override { cout <<"Derived::foo()" << endl;}
};
int main()
{
...