大约有 46,000 项符合查询结果（耗时：0.0545秒） [XML]
How to set default values in Rails?
...
"Correct" is a dangerous word in Ruby. There's usually more than one way to do anything. If you know you'll always want that default value for that column on that table, setting them in a DB migration file is the easiest way:
class SetDefault < ActiveRecord::Migration
...
How do I break a string over multiple lines?
...se "..." if you need to split lines in the middle of words or want to literally type linebreaks as \n:
key: "Antidisestab\
lishmentarianism.\n\nGet on it."
YAML is crazy.
Block scalar styles (>, |)
These allow characters such as \ and " without escaping, and add a new line (\n) to the end o...
Context switches much slower in new linux kernels
...and dances to its own tune. In other words, even if you completely disable all C states in your PC's (or server's) BIOS, this driver will still force them on during periods of brief inactivity, which are almost always happening unless an all core consuming synthetic benchmark (e.g., stress) is runni...
How to set radio button checked as default in radiogroup?
I have created RadioGroup and RadioButton dynamically as following:
8 Answers
8
...
Define make variable at rule execution time
...r are evaluated. In order to create the directory only when out.tar is actually fired, you need to move the directory creation down into the steps:
out.tar :
$(eval TMP := $(shell mktemp -d))
@echo hi $(TMP)/hi.txt
tar -C $(TMP) cf $@ .
rm -rf $(TMP)
The eval function evaluates a...
Should switch statements always contain a default clause?
...e back), I was told that it's good practice to include a default clause in all switch statements. I recently remembered this advice but can't remember what the justification was. It sounds fairly odd to me now.
...
Force browser to clear cache
...Shawn Version-control wise you could render the <link /> tags dynamically and inject the application's version as a query string parameter. Alternatively, some CMSes will have a "client resources version" as a CMS-wide setting that is appended - the site's admin can manually increase that vers...
rails - Devise - Handling - devise_error_messages
...hould help you get started. :)
Another update
The resource object is actually the model that is being used by devise (go figure).
resource.class #=> User
resource.errors.class #=> ActiveModel::Error
It also appears to be defined in a higher scope (probably coming from the contro...
How can I make SQL case sensitive string comparison on MySQL?
...y default. This means that if you search with col_name LIKE 'a%', you get all column values that start with A or a. To make this search case sensitive, make sure that one of the operands has a case sensitive or binary collation. For example, if you are comparing a column and a string that both have...
How can I distribute python programs?
...ugh I don't know how it works on Windows. You would on Windows have to install Python separately if you use distutils, in any case.
I'd probably recommend that you distribute it with disutils for Linux, and Py2exe or something similar for Windows. For OS X I don't know. If it's an end user applicat...