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ActiveRecord: size vs count
...many association, size will use the cached count directly, and not make an extra query at all.
class Image < ActiveRecord::Base
belongs_to :product, counter_cache: true
end
class Product < ActiveRecord::Base
has_many :images
end
> product = Product.first # query, load product into m...
How to add one day to a date? [duplicate]
... database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes.
Where to obtain the java.time classes?
Java SE 8, Java SE 9, Java SE 10, and later
Built-in.
Part of the standard Java API with a bundled implementation.
Java 9 adds some minor ...
C++ : why bool is 8 bits long?
...or booleans, in a way. I seem to remember Pascal implementing sets as bit strings. That is, for the following set:
{1, 2, 5, 7}
You might have this in memory:
01100101
You can, of course, do something similar in C / C++ if you want. (If you're keeping track of a bunch of booleans, it could ...
When to use static classes in C# [duplicate]
...ery cheap operation in most languages, so speed is not an issue. Adding an extra line of code to the consumer is a low cost for laying the foundation of a much more maintainable solution in the future. And finally, if you want to avoid creating instances, simply create a singleton wrapper of your cl...
When should I use a trailing slash in my URL?
...ile) when a directory is accessed, so /foo/ is /foo/index.html without the extra mess. Also, in the past, browsers would append / to the domain name, but they (Firefox, Chrome, Opera) have since changed to omit the / when accessing the homepage.
– 0b10011
Mar 7...
What is DOCTYPE?
...
In HTML (including XHTML) as used on web pages, DOCTYPE is a string that triggers one of a few browser modes (quirks mode, standards mode, almost standards mode), depending on the exact spelling of the DOCTYPE. You want to use it to select a browser mode that best suits your page.
For...
How to add additional fields to form before submit?
... you need])
function addDataToForm(form, data) {
if(typeof form === 'string') {
if(form[0] === '#') form = form.slice(1);
form = document.getElementById(form);
}
var keys = Object.keys(data);
var name;
var value;
var input;
for (var i = 0; i < keys....
What is the best practice for dealing with passwords in git repositories?
...ld have.
Often config values can be non obvious, like database connection strings and similar things.
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Mechanisms for tracking DB schema changes [closed]
...d a pre-comment SVN hook that will disallow .sql files containing the mydb string, which is a sure sign that someone copy/pasted from phpMyAdmin without proper checking.
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Is it faster to count down than it is to count up?
...culative instructions will sneak in the "Sub i and N" without incurring an extra cycle -- and -- even the crudest compiler will optimise the the "Sub i and N" out of existence.
– James Anderson
May 13 '10 at 5:47
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