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How to pull a random record using Django's ORM?
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Using order_by('?') will kill the db server on the second day in production. A better way is something like what is described in Getting a random row from a relational database.
from django.db.models.aggregates import Count
from random...
How to check if a file exists in Go?
...doesn't exist, equivalent to Python's if not os.path.exists(filename):
if _, err := os.Stat("/path/to/whatever"); os.IsNotExist(err) {
// path/to/whatever does not exist
}
To check if a file exists, equivalent to Python's if os.path.exists(filename):
Edited: per recent comments
if _, err := o...
SQL Server: Filter output of sp_who2
Under SQL Server, is there an easy way to filter the output of sp_who2? Say I wanted to just show rows for a certain database, for example.
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file_get_contents(“php://input”) or $HTTP_RAW_POST_DATA, which one is better to get the body of JSON
file_get_contents("php://input") or $HTTP_RAW_POST_DATA - which one is better to get the body of JSON request?
6 Answers...
How do I bind a WPF DataGrid to a variable number of columns?
...c readonly Dictionary<DataGrid, NotifyCollectionChangedEventHandler> _handlers;
static DataGridColumnsBehavior()
{
_handlers = new Dictionary<DataGrid, NotifyCollectionChangedEventHandler>();
}
private static void BindableColumnsPropertyChanged(DependencyObject ...
Passing parameters to addTarget:action:forControlEvents
... creating several buttons within a for loop:
for (NSInteger i = 0; i < _phoneNumbers.count; i++) {
UIButton *phoneButton = [[UIButton alloc] initWithFrame:someFrame];
[phoneButton setTitle:_phoneNumbers[i] forState:UIControlStateNormal];
[phoneButton setTag:i];
[phoneButton ad...
How to profile a bash shell script slow startup?
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PS4='+ $EPOCHREALTIME\011 '
As pointed out by @pawamoy, you can use BASH_XTRACEFD to send the output of the trace to a separate file descriptor if you have Bash 4.1 or later. From this answer:
#!/bin/bash
exec 5> command.txt
BASH_XTRACEFD="5"
echo -n "hello "
set -x
echo -n world
set +x
e...
How to tell if JRE or JDK is installed
...java in system environment).
And if you haven't, add it via
export JAVA_HOME=/path/to/java/jdk1.x
and if you unsure if you have java at all on your system just use find in terminal
i.e. find / -name "java"
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How does the C# compiler detect COM types?
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[CoClass(typeof(SpVoiceClass))]
public interface SpVoice : ISpeechVoice, _ISpeechVoiceEvents_Event { }
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How to use single storyboard uiviewcontroller for multiple subclass
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The code of line we are looking for is:
object_setClass(AnyObject!, AnyClass!)
In Storyboard -> add UIViewController give it a ParentVC class name.
class ParentVC: UIViewController {
var type: Int?
override func awakeFromNib() {
if type = 0 {
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