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How do I perform the SQL Join equivalent in MongoDB?
...ttps://docs.mongodb.org/master/reference/operator/aggregation/lookup/#pipe._S_lookup
From the docs:
{
$lookup:
{
from: <collection to join>,
localField: <field from the input documents>,
foreignField: <field from the documents of the "from" collection>...
Find which version of package is installed with pip
...hat is the difference between using pip list and doing import X and then X.__version__? Are both the package versions?
– variable
Oct 13 '19 at 4:27
...
How do I print the elements of a C++ vector in GDB?
...td::vector<int> called myVector, do the following:
print *(myVector._M_impl._M_start)@myVector.size()
To print only the first N elements, do:
print *(myVector._M_impl._M_start)@N
Explanation
This is probably heavily dependent on your compiler version, but for GCC 4.1.2, the pointer to t...
How to check if a python module exists without importing it
...mport can find something in python2, using imp
import imp
try:
imp.find_module('eggs')
found = True
except ImportError:
found = False
To find dotted imports, you need to do more:
import imp
try:
spam_info = imp.find_module('spam')
spam = imp.load_module('spam', *spam_info)
i...
Is there a foreach loop in Go?
...
https://golang.org/ref/spec#For_range
A "for" statement with a "range" clause iterates through all entries
of an array, slice, string or map, or values received on a channel.
For each entry it assigns iteration values to corresponding iteration
v...
What is a singleton in C#?
...Prevent outside instantiation
}
private static readonly Singleton _singleton = new Singleton();
public static Singleton GetSingleton()
{
return _singleton;
}
}
share
|
...
How to get number of rows using SqlDataReader in C#
...nected to the DB and it is waiting for you to do whatever you are doing in order to read/process the next result before it moves on. In this case you might get better performance if you pull in all of the data, close the connection to the DB and process the results "offline".
People seem to hate d...
Peak signal detection in realtime timeseries data
...15)
JavaScript (Dirk Lüsebrink)
TypeScript (Jerry Gamble)
Perl (Alen)
PHP (radhoo)
Rules of thumb for configuring the algorithm
lag: the lag parameter determines how much your data will be smoothed and how adaptive the algorithm is to changes in the long-term average of the data. The more st...
Stack smashing detected
... errors, since it can't add red zones there
– toasted_flakes
Jan 7 '14 at 10:35
8
This answer is ...
How can I maintain fragment state when added to the back stack?
...sion 1. Use version 2)
public class FragmentA extends Fragment {
View _rootView;
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
if (_rootView == null) {
// Inflate the layout for this fragment
_...