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Run a single migration file
...f the ruby file:
rails console
>> require "db/migrate/20090408054532_add_foos.rb"
>> AddFoos.up
Note: newer versions of rails may require AddFoos.new.up rather than AddFoos.up.
An alternative way (without IRB) which relies on the fact that require returns an array of class names:
sc...
difference between fork and branch on github
If I fork a project that's hosted on github. Do I fork all the branches? How do I know which branch my fork is based on? In other words which branch will be downloaded to my PC?
...
Can a C# class inherit attributes from its interface?
...h is searched for the attributes.</param>
/// <returns>Returns all attributes.</returns>
public static T[] GetCustomAttributes<T>( this Type type ) where T : Attribute
{
return GetCustomAttributes( type, typeof( T ), false ).Select( arg => (T)arg ).ToArray();
}
/// <...
Is there a standard sign function (signum, sgn) in C/C++?
...T val) {
return (T(0) < val) - (val < T(0));
}
Benefits:
Actually implements signum (-1, 0, or 1). Implementations here using copysign only return -1 or 1, which is not signum. Also, some implementations here are returning a float (or T) rather than an int, which seems wasteful.
Works ...
Does a view exist in ASP.NET MVC?
... aside: one of our engineers (since moved on) built a custom view engine (called MultiTenantViewEngine, so you get a sense of its purpose) that implements FindView to throw a HttpException (404) if it can't find the given view. Is this good practice? I have no idea. But wouldn't be surprised if t...
How can I export tables to Excel from a webpage [closed]
... can I export tables to Excel from a webpage. I want the export to contain all the formatting and colours.
14 Answers
...
setTimeout / clearTimeout problems
...nswered Jul 31 '17 at 21:45
zero_coolzero_cool
2,64333 gold badges2727 silver badges3737 bronze badges
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C++ map access discards qualifiers (const)
...k up a key without modifying the map.
find() returns an iterator, or const_iterator to an std::pair containing both the key (.first) and the value (.second).
In C++11, you could also use at() for std::map. If element doesn't exist the function throws a std::out_of_range exception, in contrast to o...
Bogus foreign key constraint fail
...each query (bugs.mysql.com/bug.php?id=8280), making it neccessary to write all the drop statements in one query, eg.
SET FOREIGN_KEY_CHECKS=0;
DROP TABLE my_first_table_to_drop;
DROP TABLE my_second_table_to_drop;
SET FOREIGN_KEY_CHECKS=1;
Where the SET FOREIGN_KEY_CHECKS=1 serves as an extr...
Bin size in Matplotlib (Histogram)
...width in this example could be found by: (data.max() - data.min()) / number_of_bins_you_want. The + binwidth could be changed to just 1 to make this a more easily understood example.
– Jarad
Jan 22 '18 at 17:31
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