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Random record from MongoDB
...m the mycoll collection.
db.mycoll.aggregate([{ $sample: { size: 1 } }])
If you want to select the random document(s) from a filtered subset of the collection, prepend a $match stage to the pipeline:
// Get one random document matching {a: 10} from the mycoll collection.
db.mycoll.aggregate([
...
Disabling Minimize & Maximize On WinForm?
...el = true, and set the form this.WindowState = FormWindowState.Minimized.
If you want to ever actually close the form, make a class-wide boolean _close and, in your handler, set e.Cancel to !_close, so that whenever the user clicks the X on the window, it doesn't close, but you can still close it ...
How to install a specific version of a ruby gem?
Using the command-line gem tool, how can I install a specific version of a gem?
6 Answers
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What are some examples of commonly used practices for naming git branches? [closed]
... repository interacting with my group's CVS repository for several months, now. I've made an almost neurotic number of branches, most of which have thankfully merged back into my trunk. But naming is starting to become an issue. If I have a task easily named with a simple label, but I accomplish ...
How to handle Objective-C protocols that contain properties?
...l, they have no variables or methods themselves - they only describe a specific set of attributes that is true about your class so that objects holding references to them can use them in specific ways.
That means in your class that conforms to your protocol, you have to do everything to make sure a...
How to recover a dropped stash in Git?
...mal tools. When you’re done, just blow the branch away.
Finding the hash
If you have only just popped it and the terminal is still open, you will still have the hash value printed by git stash pop on screen (thanks, Dolda).
Otherwise, you can find it using this for Linux, Unix or Git Bash for Wind...
What is the difference between t.belongs_to and t.references in rails?
What is the difference between t.references and t.belongs_to ?
Why are we having those two different words? It seems to me they do the same thing?
Tried some Google search, but find no explanation.
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Using awk to print all columns from the nth to the last
...
For non-whitespace delimiters, you can specify the Output Field Separator (OFS), e.g. to a comma: awk -F, -vOFS=, '{$1=""; print $0}' You will end up with an initial delimiter ($1 is still included, just as an empty string). You can strip that with sed though: awk -F,...
Execute a terminal command from a Cocoa app
...n/grep foo bar.txt'.
int pid = [[NSProcessInfo processInfo] processIdentifier];
NSPipe *pipe = [NSPipe pipe];
NSFileHandle *file = pipe.fileHandleForReading;
NSTask *task = [[NSTask alloc] init];
task.launchPath = @"/usr/bin/grep";
task.arguments = @[@"foo", @"bar.txt"];
task.standardOutput = pi...
How to search by key=>value in a multidimensional array in PHP
...ode:
function search($array, $key, $value)
{
$results = array();
if (is_array($array)) {
if (isset($array[$key]) && $array[$key] == $value) {
$results[] = $array;
}
foreach ($array as $subarray) {
$results = array_merge($results, sea...