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Add new field to every document in a MongoDB collection
...field" : 1, "test" : "a" }
EDIT:
In case you want to add a new_field to all your collection, you have to use empty selector, and set multi flag to true (last param) to update all the documents
db.your_collection.update(
{},
{ $set: {"new_field": 1} },
false,
true
)
EDIT:
In the above ...
How much is the overhead of smart pointers compared to normal pointers in C++?
..._ptr always has memory overhead for reference counter, though it is very small.
std::unique_ptr has time overhead only during constructor (if it has to copy the provided deleter and/or null-initialize the pointer) and during destructor (to destroy the owned object).
std::shared_ptr has time overhe...
Print list without brackets in a single row
...
print(', '.join(names))
This, like it sounds, just takes all the elements of the list and joins them with ', '.
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Proper way to handle multiple forms on one page in Django
...ta. Include some hidden inputs if your froms don't have unique fields with all possible values being not empty.
– Denis Otkidach
Oct 24 '09 at 16:39
14
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Installing PDO driver on MySQL Linux server
...
On Ubuntu you should be able to install the necessary PDO parts from apt using sudo apt-get install php5-mysql
There is no limitation between using PDO and mysql_ simultaneously. You will however need to create two connections to your DB, one with mysql_ and o...
How to get my IP address programmatically on iOS/macOS?
I would like to obtain my iPad's IP address programmatically.
How can I query the networking subsystem to find out what my IPv4 (and IPv6) addresses are?
...
Print number of keys in Redis
... key. Also Redis may actively evict some expired keys, but not necessarily all of them.
– seppo0010
Aug 24 '15 at 22:23
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Example of multipart/form-data
...6 is two hyphens shorter then the actual boundaries in the data. This is really, really hard to see with all the hyphens strung together.
– Fake Name
Jun 2 '17 at 6:39
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Get path of executable
...uriousguy: You'd want to do it if, for example, your program might get installed in a directory of the user's choosing. You need to be able to find your executable and its support files somehow.
– greyfade
Jun 25 '12 at 3:11
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Perform debounce in React.js
...>
AwesomeDebouncePromise(searchFunction, 300)
);
// The async callback is run each time the text changes,
// but as the search function is debounced, it does not
// fire a new request on each keystroke
const searchResults = useAsync(
async () => {
if (inputText.length ...