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Specifying column name in a “references” migration
...would say ignore it, as it isn't a normal part of rails, you will get 0 performance out of it, as rails' default generated SQL queries take no advantage of it. link
– mschultz
Dec 4 '12 at 1:39
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What is a wrapper class?
... a class that "wraps" around something else, just like its name.
The more formal definition of it would be a class that implements the Adapter Pattern. This allows you to modify one set of APIs into a more usable, readable form. For example, in C#, if you want to use the native Windows API, it he...
How can I output leading zeros in Ruby?
...rb(main):001:0> "%03d" % 5
=> "005"
The left-hand-side is a printf format string, and the right-hand side can be a list of values, so you could do something like:
irb(main):002:0> filename = "%s/%s.%04d.txt" % ["dirname", "filename", 23]
=> "dirname/filename.0023.txt"
Here's a print...
Log4net does not write the log in the log file
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This was my rescue. Doing a desktop Forms project and putting log4net.Config.XmlConfigurator.Configure(); in main was not helping. Thanks
– Tomas Hesse
Feb 21 '19 at 12:47
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How to prevent rm from reporting that a file was not found?
...only because it happens to be a unique abbreviation for --force. The short form -f is clearer and more portable.
– Keith Thompson
May 28 '14 at 18:09
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Convert to binary and keep leading zeros in Python
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Use the format() function:
>>> format(14, '#010b')
'0b00001110'
The format() function simply formats the input following the Format Specification mini language. The # makes the format include the 0b prefix, and the 010 si...
Error: The processing instruction target matching “[xX][mM][lL]” is not allowed
...not XML, because an extra XML declaration prevents the XML from being well-formed. Use a text editor or open the file programmatically and operate on it as text to eliminate the stray <?xml ?> declaration before treating it as an XML file.
– kjhughes
Nov...
In PHP, how do you change the key of an array element?
I have an associative array in the form key => value where key is a numerical value, however it is not a sequential numerical value. The key is actually an ID number and the value is a count. This is fine for most instances, however I want a function that gets the human-readable name of the arr...
How to write an inline IF statement in JavaScript?
...vaScripts behaviour of passing / returning one of the original values that formed the logical expression, which one depends on the type of operator. Certain other languages, like PHP, carry on the actual result of the operation i.e. true or false, meaning the result is always true or false; e.g:
14...
How to diff a commit with its parent?
...evisions(7) manpage):
Two other shorthands for naming a set that is formed by a commit and its
parent commits exist. The r1^@ notation means all parents of r1. r1^!
includes commit r1 but excludes all of its parents.
This means that you can use 15dc8^! as a shorthand for 15dc8^..1...