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When to use a “has_many :through” relation in Rails?
...f you wanted to have users belong to groups, then you could do something like this:
class Group < ActiveRecord::Base
has_many :users
end
class User < ActiveRecord::Base
belongs_to :group
end
What if you wanted to track additional metadata around the association? For example, when the ...
What is the difference between UNION and UNION ALL?
...NION instead of UNION ALL, since the database server must do additional work to remove the duplicate rows, but usually you do not want the duplicates (especially when developing reports).
UNION Example:
SELECT 'foo' AS bar UNION SELECT 'foo' AS bar
Result:
+-----+
| bar |
+-----+
| foo |
+----...
YAML mime type?
... uses application/x-yaml with an alternative of text/yaml (source).
I think it's just a matter of convention, there is no technical why, as far as I can tell.
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UITableView - change section header color
...r)section
{
UIView *headerView = [[[UIView alloc] initWithFrame:CGRectMake(0, 0, tableView.bounds.size.width, 30)] autorelease];
if (section == integerRepresentingYourSectionOfInterest)
[headerView setBackgroundColor:[UIColor redColor]];
else
[headerView setBackgroundColor:[UIColor...
Get person's age in Ruby
I'd like to get a person's age from its birthday. now - birthday / 365 doesn't work, because some years have 366 days. I came up with the following code:
...
Why not to deploy on a Friday? [closed]
Joel mentioned in StackOverflow podcast #24 that it's FogCreek company policy to not ship software on Fridays. However, he didn't elaborate as to why.
...
PHP filesize MB/KB conversion [duplicate]
...the output of PHP's filesize() function to a nice format with MegaBytes, KiloBytes etc?
12 Answers
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How to quickly open a file in Visual Studio 2012
...d one good feature no available any more (or if it still is, please let me know): in VS2010, if I know a file name, for example, MyFile.cs , I can quickly open it by typing Ctrl + D (or whatever shortcut assigned) to go to Find tool, and then type >of myfile.cs , the file will be opened then,...
Which version of PostgreSQL am I running?
...
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Reading/parsing Excel (xls) files with Python
... is a real PITA. The number of caveats is huge and the documentation is lacking and annoying. I ran into many weird bugs and gotchas, some of which took many hours to figure out.
UPDATE: For newer .xlsx files, the recommended library for reading and writing appears to be openpyxl (thanks, Ikar Poho...