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Error 1022 - Can't write; duplicate key in table
...ou can not have the same foreign key names in the database tables.
Check all your tables and all your foreign keys and avoid having two foreign keys with the same exact name.
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What is the difference between #import and #include in Objective-C?
... decent header files protect themselves against this anyway, so it's not really that much of a benefit.
Basically, it's up to you to decide which you want to use. I tend to #import headers for Objective-C things (like class definitions and such) and #include standard C stuff that I need. For exampl...
Calling constructors in c++ without new
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I guess these types of actions are optimized and therefore, do not significantly differ in performance aspects.
– M. Williams
Apr 27 '10 at 16:14
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When should I write the keyword 'inline' for a function/method?
...cade later the compiler needs no such hints. Not to mention humans are usually wrong when it comes to optimizing code, so most compilers flat out ignore the 'hint'.
static - the variable/function name cannot be used in other translation units. Linker needs to make sure it doesn't accidentally us...
How can I copy the output of a command directly into my clipboard?
... down the complete procedure just in case anyone else needs it.
First install a 16 kB program called xclip:
sudo apt-get install xclip
You can then pipe the output into xclip to be copied into the clipboard:
cat file | xclip
To paste the text you just copied, you shall use:
xclip -o
To si...
Global access to Rake DSL methods is deprecated
...
You can "delete" Rake 0.9.1 by running the following command:
gem uninstall rake -v=0.9.1
If you have multiple versions of the gem installed, you'll be prompted to pick a version.
After 0.9.1 was cleaned out, I ran
bundle update rake
and was finally able to create my database files. I was ...
OpenCV C++/Obj-C: Detecting a sheet of paper / Square Detection
...e I was unable to find a relevant implementation I decided to accept the challenge.
I made some modifications to the squares demo present in OpenCV and the resulting C++ code below is able to detect a sheet of paper in the image:
void find_squares(Mat& image, vector<vector<Point> >...
How to get the python.exe location programmatically? [duplicate]
Basically I want to get a handle of the python interpreter so I can pass a script file to execute (from an external application).
...
Format a datetime into a string with milliseconds
...etime string from the date with milliseconds. This code is typical for me and I'm eager to learn how to shorten it.
12 Ans...
How do you read a file into a list in Python? [duplicate]
...each line might have. When the with ends, the file will be closed automatically for you. This is true even if an exception is raised inside of it.
2. use of list comprehension
This could be considered inefficient as the file descriptor might not be closed immediately. Could be a potential issue wh...