大约有 45,778 项符合查询结果（耗时：0.0350秒） [XML]
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock'
...
I once had this problem and solved it by installing mysql-server, so make sure that you have installed the mysql-server, not the mysql-client or something else.
That error means the file /var/run/mysqld/mysqld.sock doesn't exists, if you didn't install mysql-...
Importing from builtin library when module with same name exists
Situation:
- There is a module in my project_folder called calendar
- I would like to use the built-in Calendar class from the Python libraries
- When I use from calendar import Calendar it complains because it's trying to load from my module.
...
Why are preprocessor macros evil and what are the alternatives?
...ved a really good answer; I think that almost any programmer before even writing the first "Hello World" had encountered a phrase like "macro should never be used", "macro are evil" and so on, my question is: why? With the new C++11 is there a real alternative after so many years?
...
Developing GUIs in Python: Tkinter vs PyQt [closed]
...erious, especially as things you learn will translate directly to working with Qt in other languages too if you ever need to, and Qt is probably the best cross-platform interface toolkit available right now.
There are only two real (potential) disadvantages:
PyQt is only available under the GPL. ...
Static Block in Java [duplicate]
...
It's a static initializer. It's executed when the class is loaded (or initialized, to be precise, but you usually don't notice the difference).
It can be thought of as a "class constructor".
Note that there are also instanc...
Simulating tremor (from e.g. Parkinson's Disease) with the mouse on a webpage?
I'm working for a foundation that raises awareness for accessibility in the internet. For a presentation, we want to offer a small workshop that simulates different disabilities/impairments to people. This is done via a website created especially for this presentation.
...
What exactly do “u” and “r” string flags do, and what are raw string literals?
...
There's not really any "raw string"; there are raw string literals, which are exactly the string literals marked by an 'r' before the opening quote.
A "raw string literal" is a slightly different syntax for a string literal, in which a backslash, \, is taken as meaning "just a backs...
Hibernate, @SequenceGenerator and allocationSize
... know the default behaviour of Hibernate when using @SequenceGenerator - it increases real database sequence by one , multiple this value by 50 (default allocationSize value) - and then uses this value as entity ID.
...
Why does string::compare return an int?
...
First, the specification is that it will return a value less
than, equal to or greater than 0, not necessarily -1 or 1.
Secondly, return values are rvalues, subject to integral
promotion, so there's no point in returning anything smaller.
In C++ (as in C),...
How to delete migration files in Rails 3
...:migrate again.
If your application is already on production or staging, it's safer to just write another migration that destroys your table or columns.
Another great reference for migrations is: http://guides.rubyonrails.org/migrations.html
...