大约有 40,000 项符合查询结果（耗时：0.0647秒） [XML]
WHERE vs HAVING
... general, you can reference aliases in neither of these clauses, but MySQL allows referencing SELECT level aliases in GROUP BY, ORDER BY and HAVING.
And are there any downsides instead of doing "WHERE 1" (writing the whole definition instead of a column name)
If your calculated expression does...
Pickle or json?
...t possible.
– User
Nov 20 '13 at 11:32
2
Apart from security, JSON has the additional advantage t...
What does “hashable” mean in Python?
...y and a set member, because these data structures use the hash value internally.
All of Python’s immutable built-in objects are hashable, while no mutable containers (such as lists or dictionaries) are. Objects which are instances of user-defined classes are hashable by default; they all comp...
How do I implement interfaces in python?
...interface, a module that is a part of the Zope Component Architecture, a really awesomely cool component framework. Here you don't subclass from the interfaces, but instead mark classes (or even instances) as implementing an interface. This can also be used to look up components from a component reg...
The maximum recursion 100 has been exhausted before statement completion
...he end of the query:
...
from EmployeeTree
option (maxrecursion 0)
That allows you to specify how often the CTE can recurse before generating an error. Maxrecursion 0 allows infinite recursion.
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What is the difference between std::array and std::vector? When do you use one over other? [duplicat
...ssic C array. That means its size is fixed at compile time and it will be allocated as a single chunk (e.g. taking space on the stack). The advantage it has is slightly better performance because there is no indirection between the object and the arrayed data.
std::vector is a small class contain...
“Private” (implementation) class in Python
I am coding a small Python module composed of two parts:
7 Answers
7
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Unignore subdirectories of ignored directories in Git
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I have a global gitignore file where I ignored all *.zip file. Yet for a particular project, I want to include zip files. I added this line to that project's .gitignore and it works great!: !*.zip
– Jinghao Shi
Mar 21 '15 at 3:44
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How can I create directories recursively? [duplicate]
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Specifically: os.makedirs(os.path.join("/home/dail", "first", "second", "third"))
– mseery
May 14 '11 at 22:41
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How do I daemonize an arbitrary script in unix?
... & operator:
nohup yourScript.sh script args&
The nohup command allows you to shut down your shell session without it killing your script, while the & places your script in the background so you get a shell prompt to continue your session. The only minor problem with this is standard ...