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Mongodb Explain for Aggregation framework
...erations
explain:true
db.collection.aggregate([
{ $project : { "Tags._id" : 1 }},
{ $unwind : "$Tags" },
{ $match: {$or: [{"Tags._id":"tag1"},{"Tags._id":"tag2"}]}},
{ $group: {
_id : "$_id",
count: { $sum:1 }
}},
{$sort: {"count":-1}}
],
{
explain...
Unique Constraint in Entity Framework Code First
...
CreateIndex("TableName", new string[2] { "Column1", "Column2" }, true, "IX_UniqueColumn1AndColumn2");
Something like that:
namespace Sample.Migrations
{
using System;
using System.Data.Entity.Migrations;
public partial class TableName_SetUniqueCompositeIndex : DbMigration
{
...
How can I delete all Git branches which have been merged?
...ip, you can add it to the egrep command like the following. The branch skip_branch_name will not be deleted.
git branch --merged| egrep -v "(^\*|master|dev|skip_branch_name)"
To delete all local branches that are already merged into the currently checked out branch:
git branch --merged | egrep -v "...
CGContextDrawImage draws image upside down when passed UIImage.CGImage
...ingPrintingiOS/GraphicsDrawingOverview/GraphicsDrawingOverview.html#//apple_ref/doc/uid/TP40010156-CH14-SW4
Flipping the Default Coordinate System
Flipping in UIKit drawing modifies the backing CALayer to align a drawing environment having a LLO coordinate system with the default coordinate...
Convert.ChangeType() fails on Nullable Types
...a series of blog posts including this at http://www.endswithsaurus.com/2010_07_01_archive.html (Scroll down to the Addendum, @JohnMacintyre actually spotted the bug in my original code which led me down the same path you're on now). I have a couple of small modifications since that post that includ...
Renaming a virtualenv folder without breaking it
...e
use relative paths, and will change
all the scripts to use
activate_this.py instead of using the
location of the Python interpreter to
select the environment.
Note: you must run this after you've
installed any packages into the
environment. If you make an
environment relocatab...
Group by multiple columns in dplyr, using string vector input
...
Since this question was posted, dplyr added scoped versions of group_by (documentation here). This lets you use the same functions you would use with select, like so:
data = data.frame(
asihckhdoydkhxiydfgfTgdsx = sample(LETTERS[1:3], 100, replace=TRUE),
a30mvxigxkghc5cdsvxvyv0ja = s...
How does std::move() transfer values into RValues?
...ch I cleaned up a little bit):
template <typename T>
typename remove_reference<T>::type&& move(T&& arg)
{
return static_cast<typename remove_reference<T>::type&&>(arg);
}
Let's start with the easier part - that is, when the function is called wi...
nonlocal keyword in Python 2.x
... @BobStein Sorry, I don't really understand what you mean. But by adding __slots__ = () and creating an object instead of using the class, e.g. context.z = 3 would raise an AttributeError. It is possible for all classes, unless they inherit from a class not defining slots.
– ...
set date in input type date
...swered Nov 10 '12 at 14:30
int32_tint32_t
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