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How can I rename a database column in a Ruby on Rails migration?
...tion to add columns with the new name(s) and populate them with the values from the old column name.
class AddCorrectColumnNames < ActiveRecord::Migration
def up
add_column :table, :correct_name_column_one, :string
add_column :table, :correct_name_column_two, :string
puts 'Updatin...
Where is shared_ptr?
...
Having stepped away from C++ briefly I was surprised to find that (in clang v3.1) shared_ptr was still sitting in a tr1 namespace. Any thoughts on this?
– hiwaylon
Aug 8 '12 at 12:37
...
Temporarily disable some plugins using pathogen in vim.
...the g:pathogen_disabled variable, before starting pathogen.
So an example from my own vimrc
" To disable a plugin, add it's bundle name to the following list
let g:pathogen_disabled = []
" for some reason the csscolor plugin is very slow when run on the terminal
" but not in GVim, so disable it i...
binning data in python with scipy/numpy
...s in the previous answers, the Scipy solution would be
import numpy as np
from scipy.stats import binned_statistic
data = np.random.rand(100)
bin_means = binned_statistic(data, data, bins=10, range=(0, 1))[0]
share
...
What does Bump Version stand for?
... helps avoid two people bumping the version unaware of each other. 1. bump from -SNAPSHOT to a release (with same version number). 2. commit 3. bump to next version number and place -SNAPSHOT back. 4. commit 5. push
– akauppi
Dec 27 '16 at 12:41
...
Can not connect to local PostgreSQL
...ns, or of you have a distribution installed someplace and have another (eg from source) installation elsewhere), with client and server using different rendez-vous addresses.
If postgres is running, and the socket actually exists, you could use:
psql -h /the/directory/where/the/socket/was/found ...
Get last element of Stream/List in a one-liner
...s implementations works for all ordered streams (including streams created from Lists). For unordered streams it is for obvious reasons unspecified which element will be returned.
The implementation works for both sequential and parallel streams. That might be surprising at first glance, and unfort...
C++ SFINAE examples?
...
Heres one example (from here):
template<typename T>
class IsClassT {
private:
typedef char One;
typedef struct { char a[2]; } Two;
template<typename C> static One test(int C::*);
// Will be chosen if T is anything...
Setting a timeout for socket operations
...
socket.connect(new InetSocketAddress(ipAddress, port), 1000);
Quoting from the documentation
connect
public void connect(SocketAddress endpoint, int timeout) throws IOException
Connects this socket to the server with a specified timeout value. A timeout of zero is interpreted as an i...
Android Studio needs JDK 7 for Android-L mac
... detail solution step-by-step
For Mac
Download the DMG file of JDK-7 from here
Click on DMG and follow the instructions . It will install and configure JDK-7 on mac .
Now in your android studio go to File->Project Structure -> SDK Location .
In JDK location click on browse and go to /-&...