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E11000 duplicate key error index in mongodb mongoose
... null value.
In other words, a sparse index is ok with multiple documents all having null values.
sparse indexes
From comments:
Your error says that the key is named mydb.users.$email_1 which makes me suspect that you have an index on both users.email and users.local.email (The former being old an...
Remove Object from Array using JavaScript
...
This however will remove all the occurrences found, not only the first one
– Flavien Volken
Jul 12 '16 at 6:49
6
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Get the (last part of) current directory name in C#
...the last part of current directory, for example from /Users/smcho/filegen_from_directory/AIRPassthrough , I need to get AIRPassthrough .
...
How get integer value from a enum in Rails?
...t the integer values for an enum from the class the enum is on:
Model.sale_infos # Pluralized version of the enum attribute name
That returns a hash like:
{ "plan_1" => 1, "plan_2" => 2 ... }
You can then use the sale_info value from an instance of the Model class to access the integer v...
How do you create a Swift Date object?
... dateFromString. If you wanted to return a nil on bad parses, you would ideally use a failible initializer; but you cannot do that now (June 2015), because of a limitation in Swift 1.2, so then you're next best choice is to use a class factory method.
A more elaborate example, which addresses both ...
Using CookieContainer with WebClient class
... limited functionalty. Before I knew about this option, I wrote lots of really painful code at the HttpWebRequest layer because WebClient almost, but not quite, did what I needed. Derivation is much easier.
Another option is to use the regular WebClient class, but manually populate the Cookie he...
get size of json object
... check the size i.e. like that:
var data = {one : 1, two : 2, three : 3};
_.size(data);
//=> 3
_.keys(data);
//=> ["one", "two", "three"]
_.keys(data).length;
//=> 3
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Catch Ctrl-C in C
...ote this answer seven years ago. Yes, language standards change. If you really must better the world, please add your new answer but leave mine as is. As the answer has my name on it, I'd prefer it to contain my words too. Thank you.
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Why do I have to access template base class members through the this pointer?
...emplate parameter. Others are deferred until the parameter is known. It's called two-phase compilation, and MSVC doesn't do it but it's required by the standard and implemented by the other major compilers. If you like, the compiler must compile the template as soon as it sees it (to some kind of in...
Python: Ignore 'Incorrect padding' error when base64 decoding
... of which were base64 without padding:
import base64
import re
def decode_base64(data, altchars=b'+/'):
"""Decode base64, padding being optional.
:param data: Base64 data as an ASCII byte string
:returns: The decoded byte string.
"""
data = re.sub(rb'[^a-zA-Z0-9%s]+' % altcha...