rename_column :table, :old_column, :new_column
You'll probably want to create a separate migration to do this. (Rename FixColumnName
as you will.):
script/generate migration FixColumnName
# creates db/migrate/xxxxxxxxxx_fix_column_name.rb
Then edit the migration to do your will:
# db/migrate/xxxxxxxxxx_fix_column_name.rb
class FixColumnName < ActiveRecord::Migration
def self.up
rename_column :table_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 migration is rolled back without the need to write a separate down method".
See "Active Record Migrations" for more information.
rails g migration FixColumnName
class FixColumnName < ActiveRecord::Migration
def change
rename_column :table_name, :old_column, :new_column
end
end
If you happen to have a whole bunch of columns to rename, or something that would have required repeating the table name over and over again:
rename_column :table_name, :old_column1, :new_column1
rename_column :table_name, :old_column2, :new_column2
...
You could use change_table
to keep things a little neater:
class FixColumnNames < ActiveRecord::Migration
def change
change_table :table_name do |t|
t.rename :old_column1, :new_column1
t.rename :old_column2, :new_column2
...
end
end
end
Then just db:migrate
as usual or however you go about your business.
For Rails 4:
While creating a Migration
for renaming a column, Rails 4 generates a change
method instead of up
and down
as mentioned in the above section. The generated change
method is:
$ > rails g migration ChangeColumnName
which will create a migration file similar to:
class ChangeColumnName < ActiveRecord::Migration
def change
rename_column :table_name, :old_column, :new_column
end
end
Python 2.7.9+ and 3.4+
Good news! Python 3.4 (released March 2014) and Python 2.7.9 (released December 2014) ship with Pip. This is the best feature of any Python release. It makes the community's wealth of libraries accessible to everyone. Newbies are no longer excluded from using community libraries by the prohibitive difficulty of setup. In shipping with a package manager, Python joins Ruby, Node.js, Haskell, Perl, Go—almost every other contemporary language with a majority open-source community. Thank you, Python.
If you do find that pip is not available when using Python 3.4+ or Python 2.7.9+, simply execute e.g.:
py -3 -m ensurepip
Of course, that doesn't mean Python packaging is problem solved. The experience remains frustrating. I discuss this in the Stack Overflow question Does Python have a package/module management system?.
And, alas for everyone using Python 2.7.8 or earlier (a sizable portion of the community). There's no plan to ship Pip to you. Manual instructions follow.
Python 2 ≤ 2.7.8 and Python 3 ≤ 3.3
Flying in the face of its 'batteries included' motto, Python ships without a package manager. To make matters worse, Pip was—until recently—ironically difficult to install.
Official instructions
Per https://pip.pypa.io/en/stable/installing/#do-i-need-to-install-pip:
Download get-pip.py
, being careful to save it as a .py
file rather than .txt
. Then, run it from the command prompt:
python get-pip.py
You possibly need an administrator command prompt to do this. Follow Start a Command Prompt as an Administrator (Microsoft TechNet).
This installs the pip package, which (in Windows) contains ...\Scripts\pip.exe that path must be in PATH environment variable to use pip from the command line (see the second part of 'Alternative Instructions' for adding it to your PATH,
Alternative instructions
The official documentation tells users to install Pip and each of its dependencies from source. That's tedious for the experienced and prohibitively difficult for newbies.
For our sake, Christoph Gohlke prepares Windows installers (.msi
) for popular Python packages. He builds installers for all Python versions, both 32 and 64 bit. You need to:
- Install setuptools
- Install pip
For me, this installed Pip at C:\Python27\Scripts\pip.exe
. Find pip.exe
on your computer, then add its folder (for example, C:\Python27\Scripts
) to your path (Start / Edit environment variables). Now you should be able to run pip
from the command line. Try installing a package:
pip install httpie
There you go (hopefully)! Solutions for common problems are given below:
Proxy problems
If you work in an office, you might be behind an HTTP proxy. If so, set the environment variables http_proxy
and https_proxy
. Most Python applications (and other free software) respect these. Example syntax:
http://proxy_url:port
http://username:password@proxy_url:port
If you're really unlucky, your proxy might be a Microsoft NTLM proxy. Free software can't cope. The only solution is to install a free software friendly proxy that forwards to the nasty proxy. http://cntlm.sourceforge.net/
Unable to find vcvarsall.bat
Python modules can be partly written in C or C++. Pip tries to compile from source. If you don't have a C/C++ compiler installed and configured, you'll see this cryptic error message.
Error: Unable to find vcvarsall.bat
You can fix that by installing a C++ compiler such as MinGW or Visual C++. Microsoft actually ships one specifically for use with Python. Or try Microsoft Visual C++ Compiler for Python 2.7.
Often though it's easier to check Christoph's site for your package.
Best Answer
This question is similar to How to run all tests with minitest?
Using Ruby 1.9.3 and Rake 0.9.2.2, given a directory layout like this:
Here is what
alpha_spec.rb
might look like:And here's
Rakefile
You can run
rake test
ruby -Ilib spec/alpha_spec.rb
I don't know if using a
spec_helper.rb
with minitest is common or not. There does not appear to be a convenience method for loading one. Add this to the Rakefile:Then
spec/spec_helper.rb
can contain various redundant things:And
spec/alpha_spec.rb
replaces the redundant parts with:rake test
ruby -Ilib -Ispec spec/alpha_spec.rb