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How can I rename a field for all documents in MongoDB?
...ll your records.
Or you can use the former way:
remap = function (x) {
if (x.additional){
db.foo.update({_id:x._id}, {$set:{"name.last":x.name.additional}, $unset:{"name.additional":1}});
}
}
db.foo.find().forEach(remap);
In MongoDB 3.2 you can also use
db.students.updateMany( {}, { $r...
django admin - add custom form fields that are not part of the model
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If for some reason, you get an AttributeError: Unable to lookup "extra_field"..., try adding a label to the extra_field definition. It seems that django tries to "guess" the label for it, by looking at the Model and the Model...
How to implement the Android ActionBar back button?
...ress the back button. This should be done in the AndroidManifest.xml too.
Now you can enable the back button in the onCreate method of your "child" activity.
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getActionBar().setDisplayHomeAsUp...
Check that an email address is valid on iOS [duplicate]
...
return [emailTest evaluateWithObject:self];
}
@end
And then utilize:
if([@"emailString@email.com" isValidEmail]) { /* True */ }
if([@"InvalidEmail@notreallyemailbecausenosuffix" isValidEmail]) { /* False */ }
share
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How to encrypt/decrypt data in php?
...= openssl_random_pseudo_bytes($key_size, $strong);
// $strong will be true if the key is crypto safe
This can be done once or multiple times (if you wish to create a chain of encryption keys). Keep these as private as possible.
IV
The initialisation vector adds randomness to the encryption and r...
How to compile a static library in Linux?
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$< - means just the first prerequisite
ar - a Linux tool to create, modify, and extract from archives see the man pages for further information. The options in this case mean:
r - replace files existing inside the archive
c - create a archive if not already existent
s - create an object-file i...
C++ convert hex string to signed integer
...dard, there are a few new utility functions which you can make use of! specifically, there is a family of "string to number" functions (http://en.cppreference.com/w/cpp/string/basic_string/stol and http://en.cppreference.com/w/cpp/string/basic_string/stoul). These are essentially thin wrappers aroun...
Spring RestTemplate timeout
...s for all calls through this rest template (which is a singleton). Do you know if it is possible to control the timeouts per request? (eg: 10 sec for a post call and 5 sec for a get call etc)
– codesalsa
Apr 20 '16 at 23:39
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Why do I get a segmentation fault when writing to a “char *s” initialized with a string literal, but
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See the C FAQ, Question 1.32
Q: What is the difference between these initializations?
char a[] = "string literal";
char *p = "string literal";
My program crashes if I try to assign a new value to p[i].
A: A string literal (the formal term
for a double-quot...
What really happens in a try { return x; } finally { x = null; } statement?
I saw this tip in another question and was wondering if someone could explain to me how on earth this works?
5 Answers
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