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Random record from MongoDB
...llection.
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([
{ $match: { a:...
IntelliJ shortcut to show a popup of methods in a class that can be searched
... the list or highlight the desired element. Press Enter to navigate to the selected element.
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Why there is no ForEach extension method on IEnumerable?
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Couldn't you just use Select instead of your Apply method? It seems to me that applying an action to each element and yielding it is exactly what Select does. E.g. numbers.Select(n => n*2);
– rasmusvhansen
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How to remove all namespaces from XML with C#?
... return new XElement(xmlDocument.Name.LocalName, xmlDocument.Elements().Select(el => RemoveAllNamespaces(el)));
}
It's working 100%, but I have not tested it much so it may not cover some special cases... But it is good base to start.
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Modifying a subset of rows in a pandas dataframe
...The df.A==0 expression creates a boolean series that indexes the rows, 'B' selects the column. You can also use this to transform a subset of a column, e.g.:
df.loc[df.A==0, 'B'] = df.loc[df.A==0, 'B'] / 2
I don't know enough about pandas internals to know exactly why that works, but the basic is...
LINQ - Left Join, Group By, and Count
...into j1
from j2 in j1.DefaultIfEmpty()
group j2 by p.ParentId into grouped
select new { ParentId = grouped.Key, Count = grouped.Count(t=>t.ChildId != null) }
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Count work days between two dates
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For workdays, Monday to Friday, you can do it with a single SELECT, like this:
DECLARE @StartDate DATETIME
DECLARE @EndDate DATETIME
SET @StartDate = '2008/10/01'
SET @EndDate = '2008/10/31'
SELECT
(DATEDIFF(dd, @StartDate, @EndDate) + 1)
-(DATEDIFF(wk, @StartDate, @EndDate) *...
Xcode is not currently available from the Software Update server
...e Xcode command line tools is pointed correctly using this command
xcode-select -p
Which might show some path like
/Applications/Xcode.app/Contents/Developer
Change the path to correct path using the switch command
xcode-select --switch /Library/Developer/CommandLineTools/
this should...
In Angular, I need to search objects in an array
...ById')($scope.fish, fish_id);
console.log(found);
$scope.selected = JSON.stringify(found);
}
}]);
If there are any questions just let me know.
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MySQL indexes - what are the best practices?
...t them. Generally I put an index on any fields that I will be searching or selecting using a WHERE clause but sometimes it doesn't seem so black and white.
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