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What's the $unwind operator in MongoDB?
...g and obtaining the data from your storage locations.
That being said, in order to understand the concept behind the $unwind parameter, you first must understand what the use case that you are trying to quote is saying. The example document from mongodb.org is as follows:
{
title : "this is my ti...
How do you detect where two line segments intersect? [closed]
...Specifically, h is how much you have to multiply the length of the line in order to exactly touch the other line.
Therefore, If h<0, it means the rectangle line is "behind" the given line (with "direction" being "from A to B"), and if h>1 the rectangle line is "in front" of the given line.
D...
What are naming conventions for MongoDB?
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Naming convention for collection
In order to name a collection few precautions to be taken :
A collection with empty string (“”) is not a valid collection name.
A collection name should not contain the null character because this defines the end of collect...
Is it possible to view RabbitMQ message contents directly from the command line?
...RabbitMQ queue to local files and requeuing the messages in their original order.
Example usage (to dump the first 50 messages of queue incoming_1):
rabbitmq-dump-queue -url="amqp://user:password@rabbitmq.example.com:5672/" -queue=incoming_1 -max-messages=50 -output-dir=/tmp
...
How do you configure logging in Hibernate 4 to use SLF4J
...4j would kick in. It didn't though. I had to set that directly to log4j in order for that to work. Odd. What's the point of slf4j as an option for this config then?
– Travis Spencer
Apr 16 '16 at 8:36
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Get record counts for all tables in MySQL database
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add "select * from (" at beginning and ") as output order by exact_row_count desc" at the end of generated query after removing last UNION to get order by table count desc
– Raghavendra
Jun 22 '18 at 5:42
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Convert Elixir string to integer or float
...ust be the string representation of a float including a decimal point. In order to parse a string without decimal point as a float then Float.parse/1 should be used. Otherwise, an ArgumentError will be raised.
But Float.parse returns a tuple of 2 elements, not the number you want, so put it into p...
Forward declaration of a typedef in C++
...orward declaration can be made if we only need to know the type exists, in order to create pointers or references to the type. Since the OP didn't show code, but complained it wouldn't compile, I assumed (probably correctly) that the OP was trying to use the type, not just refer to it.
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Loop through all nested dictionary values?
...he first benefit. Also, this version can be adapted to different traversal orders quite easily by replacing the stack (a list) by a deque or even a priority queue.
– Fred Foo
May 25 '12 at 15:30
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How to measure time in milliseconds using ANSI C?
...ng that timeval::tv_usec is always under one second, it's looping. I.e. in order to take differences of time larger than 1 sec, you should: long usec_diff = (e.tv_sec - s.tv_sec)*1000000 + (e.tv_usec - s.tv_usec);
– Alexander Malakhov
Oct 15 '12 at 4:06
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