大约有 44,868 项符合查询结果（耗时：0.0584秒） [XML]
How do I get the object if it exists, or None if it does not exist?
When I ask the model manager to get an object, it raises DoesNotExist when there is no matching object.
18 Answers
...
Check to see if python script is running
...I quickly check (using python) if my daemon is running and, if not, launch it?
19 Answers
...
What did MongoDB not being ACID compliant before v4 really mean?
...a database expert and have no formal computer science background, so bear with me. I want to know the kinds of real world negative things that can happen if you use an old MongoDB version prior to v4 , which were not ACID compliant. This applies to any ACID noncompliant database.
...
Can a shell script set environment variables of the calling shell? [duplicate]
I'm trying to write a shell script that, when run, will set some environment variables that will stay set in the caller's shell.
...
Set cURL to use local virtual hosts
Using Apache or Ngnix I always create development sites based on real projects such as http://project1.loc which, after adding to my .hosts file, the browser has no problem using.
...
How should I detect unnecessary #include files in a large C++ project?
...n a large C++ project in Visual Studio 2008, and there are a lot of files with unnecessary #include directives. Sometimes the #include s are just artifacts and everything will compile fine with them removed, and in other cases classes could be forward declared and the #include could be moved to t...
What are the pros and cons of performing calculations in sql vs. in your application
...
It depends on a lot of factors - but most crucially:
complexity of calculations (prefer doing complex crunching on an app-server, since that scales out; rather than a db server, which scales up)
volume of data (if you need ...
MySQL Error 1093 - Can't specify target table for update in FROM clause
I have a table story_category in my database with corrupt entries. The next query returns the corrupt entries:
16 Answers...
Calling clojure from java
Most of the top google hits for "calling clojure from java" are outdated and recommend using clojure.lang.RT to compile the source code. Could you help with a clear explanation of how to call Clojure from Java assuming you have already built a jar from the Clojure project and included it in the cl...
Explain the use of a bit vector for determining if all characters are unique
I am confused about how a bit vector would work to do this (not too familiar with bit vectors). Here is the code given. Could someone please walk me through this?
...