大约有 40,000 项符合查询结果（耗时：0.0585秒） [XML]
Django filter queryset __in for *every* item in list
...
Summary:
One option is, as suggested by jpic and sgallen in the comments, to add .filter() for each category. Each additional filter adds more joins, which should not be a problem for small set of categories.
There is the aggregation approach. This query would ...
How to debug PDO database queries?
Before moving to PDO, I created SQL queries in PHP by concatenating strings. If I got database syntax error, I could just echo the final SQL query string, try it myself on the database, and tweak it until I fixed the error, then put that back into the code.
...
jQuery 'input' event
... limited to -- pressing keys which modify the input (so, for example, Ctrl by itself will not trigger the event, but Ctrl-V to paste some text will), selecting an auto-completion option, Linux-style middle-click paste, drag-and-drop, and lots of other things.
See this page and the comments on this ...
Checking network connection
...is not working, you can find a current IP address for google.com (on unix) by running
% dig google.com +trace
...
google.com. 300 IN A 216.58.192.142
share
|
improve this answer
...
Checking out Git tag leads to “detached HEAD state”
... a git checkout v2.0, you are switching to a commit that is not pointed to by a branch. The HEAD is now "detached" and not pointing to a branch. If you decide to make a commit now (as you may), there's no branch pointer to update to track this commit. Switching back to another commit will make you l...
Removing the fragment identifier from AngularJS urls (# symbol)
... Because IE lt 10 doesn't support html5 history API which were enabled by setting up html5Mode(true). In IE you have to use # in routes.
– Maxim Grach
Feb 8 '13 at 16:50
...
Is Meyers' implementation of the Singleton pattern thread safe?
...r comments.
In C++03, this code wasn't thread safe. There is an article by Meyers called "C++ and the Perils of Double-Checked Locking" which discusses thread safe implementations of the pattern, and the conclusion is, more or less, that (in C++03) full locking around the instantiating method is ...
Git alias with positional parameters
...portant - it prevents all the user-supplied arguments from being processed by the shell (it comments them out).
Note: git puts all user-supplied arguments at the end of the command line. To see this in action, try: GIT_TRACE=2 git files a b c d
The escaped (due to nesting) quotes are important for...
How to return a part of an array in Ruby?
...
Yes, Ruby has very similar array-slicing syntax to Python. Here is the ri documentation for the array index method:
--------------------------------------------------------------- Array#[]
array[index] -> obj...
How to do an INNER JOIN on multiple columns
...ct and I'm supposed to perform a database query which finds flights either by the city name or the airport code, but the flights table only contains the airport codes so if I want to search by city I have to join on the airports table.
...