大约有 40,000 项符合查询结果（耗时：0.0371秒） [XML]
mongodb group values by multiple fields
... $slice just off the basic aggregation result. For "large" results, run parallel queries instead for each grouping ( a demonstration listing is at the end of the answer ), or wait for SERVER-9377 to resolve, which would allow a "limit" to the number of items to $push to an array.
db.books.aggregate(...
Dealing with commas in a CSV file
...any easily-available csv library - that is to say RFC 4180.
There's actually a spec for CSV format and how to handle commas:
Fields containing line breaks (CRLF), double quotes, and commas should be enclosed in double-quotes.
http://tools.ietf.org/html/rfc4180
So, to have values foo and ...
Detect Browser Language in PHP
... do you say they are one letter? Dutch (nl), Greek (el) and Slovenian (sl) all appear to be two letter: msdn.microsoft.com/en-us/library/ms533052(v=vs.85).aspx
– Peter K.
Nov 19 '12 at 17:35
...
How do I get a list of column names from a psycopg2 cursor?
... to generate column labels directly from the selected column names, and recall seeing that python's psycopg2 module supports this feature.
...
How do you validate a URL with a regular expression in Python?
...he result of parsing gives you a netloc or path you don't like, you could call that "invalid".
– S.Lott
Jun 29 '09 at 20:44
2
...
Rails :include vs. :joins
...de functionality was changed with Rails 2.1. Rails used to do the join in all cases, but for performance reasons it was changed to use multiple queries in some circumstances. This blog post by Fabio Akita has some good information on the change (see the section entitled "Optimized Eager Loading")....
PHP - how to best determine if the current invocation is from CLI or web server?
...
A small caveat about this method: it will not return "cli" when run from a cron job. There's a number od differents keys to choose from inside of $_SERVER to determine more reliably whether the request came via HTTP or not.
...
How to add target=“_blank” to JavaScript window.location?
...
@twinlakes this gets blocked in all modern browsers.
– Ben Racicot
Nov 4 '15 at 15:21
...
Putty: Getting Server refused our key Error
...
OK, there was a small typo in my key. Apparently when pasting to file the first letter was cut off and it started with sh-rsa instead of ssh-rsa.
nrathathaus - your answer was very helpful, thanks a lot, this answer is credited to you :) I di...
Bash Templating: How to build configuration files from templates with Bash?
...\}/defined $ENV{$1} ? $ENV{$1} : $&/eg' < template.txt
to replace all ${...} strings with corresponding enviroment variables (do not forget to export them before running this script).
For pure bash this should work (assuming that variables do not contain ${...} strings):
#!/bin/bash
while...