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When to use a “has_many :through” relation in Rails?
...p
# has attributes for date_joined and role
end
This introduces a new table, and eliminates the group_id column from the user's table.
The problem with this code is that you'd have to update every where else you use the user class and change it:
user.groups.first.name
# becomes
user.group_m...
Rolling or sliding window iterator?
...I changed it to individually look up and add items in a window of ten, the tables turned and the tee method was 20% faster. I was able to recover some speed by using negative indexes for the last five terms in the addition, but tee was still a little faster. Overall I would estimate that either one ...
How can I send an inner to the bottom of its parent ?
...ircumstances, a better solution is to make the grandparent element display:table; and the parent element display:table-cell;vertical-align:bottom;. After doing this, you should be able to give the the child elements display:inline-block; and they will automagically flow towards the bottom of the pa...
How may I align text to the left and text to the right in the same line?
...untime that it looks bad.
What I like to do is simply create a single row table and apply the right float on the second cell. No need to apply a left-align on the first, that happens by default. This handles overlap perfectly by word-wrapping.
HTML
<table style="width: 100%;">
<tr>&...
Error installing mysql2: Failed to build gem native extension
...\models\city.rb to look like this
class City < ActiveRecord::Base
set_table_name "city"
end
Edit the file c:\Sites\world\config\database.yml to look like this
development:
adapter: mysql2
encoding: utf8
database: world
pool: 5
username: root
password: root
socket: /tmp/mysql.sock
add to ge...
How to use an existing database with an Android application [duplicate]
...r getTestData() {
try {
String sql ="SELECT * FROM myTable";
Cursor mCur = mDb.rawQuery(sql, null);
if (mCur != null) {
mCur.moveToNext();
}
return mCur;
} catch (SQLException mSQLException) {
...
How to subtract 30 days from the current datetime in mysql?
...
SELECT * FROM table
WHERE exec_datetime BETWEEN DATE_SUB(NOW(), INTERVAL 30 DAY) AND NOW();
http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html#function_date-add
...
How do I convert a pandas Series or index to a Numpy array? [duplicate]
...ke this:
dd = list(zone[0]) #Where zone[0] is some specific column of the table
idx = dd.index(filename[i])
You have you index value as idx.
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Difference between “read commited” and “repeatable read”
..., will find the Same data, data is free to change after it was read.
Repeatable read is a higher isolation level, that in addition to the guarantees of the read committed level, it also guarantees that any data read cannot change, if the transaction reads the same data again, it will find the previ...
How to prevent form resubmission when page is refreshed (F5 / CTRL+R)
I have a simple form that submits text to my SQL table. The problem is that after the user submits the text, they can refresh the page and the data gets submitted again without filling the form again. I could redirect the user to another page after the text is submitted, but I want users to stay on ...