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How can I rename a database column in a Ruby on Rails migration?
...le_name, :old_column, :new_column
end
def self.down
# rename back if you need or do something else or do nothing
end
end
For Rails 3.1 use:
While, the up and down methods still apply, Rails 3.1 receives a change method that "knows how to migrate your database and reverse it when the ...
How to convert string into float in JavaScript?
...
If they're meant to be separate values, try this:
var values = "554,20".split(",")
var v1 = parseFloat(values[0])
var v2 = parseFloat(values[1])
If they're meant to be a single value (like in French, where one-half is writ...
Regular expression to match any character being repeated more than 10 times
...he same character being repeated more than 10 or so times. So for example, if I have a document littered with horizontal lines:
...
How to access array elements in a Django template?
...
Remember that the dot notation in a Django template is used for four different notations in Python. In a template, foo.bar can mean any of:
foo[bar] # dictionary lookup
foo.bar # attribute lookup
foo.bar() # method call
foo[bar] # list-index lookup
It tries them in t...
Why do browsers match CSS selectors from right to left?
... left. So they first find the children and then check their parents to see if they match the rest of the parts of the rule.
...
Is there a DesignMode property in WPF?
...ass MyUserControl : UserControl
{
public MyUserControl()
{
if (DesignerProperties.GetIsInDesignMode(this))
{
// Design-mode specific functionality
}
}
}
share
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...
Jquery selector input[type=text]')
...elector:
$('.sys input[type=text], .sys select').each(function() {...})
If you don't like the repetition:
$('.sys').find('input[type=text],select').each(function() {...})
Or more concisely, pass in the context argument:
$('input[type=text],select', '.sys').each(function() {...})
Note: Inter...
What happens to a detached thread when main() exits?
... joined again" is:
Yes, with the *_at_thread_exit family of functions (notify_all_at_thread_exit(), std::promise::set_value_at_thread_exit(), ...).
As noted in footnote [2] of the question, signalling a condition variable or a semaphore or an atomic counter is not sufficient to join a detached thr...
how to return index of a sorted list? [duplicate]
...return a list with the index of the sorted items in the list. For example, if the list I want to sort is [2,3,1,4,5] , I need [2,0,1,3,4] to be returned.
...
NPM - How to fix “No readme data”
...
If you set "private": true in your package.json, then npm will refuse to publish it. ref: https://www.npmjs.org/doc/files/package.json.html
– AlexStack
Nov 5 '14 at 12:51
...