For string columns, MySQL indexes the left side of a string. That means an index can speed a like query...
Be careful when stubbing out attributes on records that are defined by associations. Nothing is as it seems to be...
No one wants to cry over regression issues in views; does testing HTML and CSS have to be such a...
So you got this error, even though your Gemfile bundles mysql2: !!! Missing the mysql2 gem. Add it to your Gemfile...
The next version of MySQL will include a built-in memcached daemon. This daemon can quickly get and set key/value...
assignable_values now lets you define a secondary default that is only used if the primary default value is not...
paper_trail is an excellent gem to track record versions and changes. You almost never want to reimplement something like...
The will_paginate gem will show a default of 30 records per page. If you want to test pagination in...
Unless you changed the default, this will be 16 MB: mysql> SHOW VARIABLES WHERE Variable_name="max_allowed_packet"; +--------------------+----------+
Sometimes, you may want to open up a second database connection, to a read slave or another database. When doing...
Take care in queries where multiple AND or OR operators are used. In doubt, always use braces to enforce precedence...
This will make MySQL log all received queries so you can see for yourself what happens on the database level...
I highly recommend that you make use of RubyMine's feature to pin tabs. When you pin all "important" files...
ActiveSupport >= 3 has Date.parse('2011-02-10').beginning_of_quarter #=> 2011-01-01 Date.parse('2011-02-10').end_of_quarter...
If you upgrade to the mysql2 gem, you will run into the problem that the server's database.yml (which is...
Some advice for bulk loading many records into InnoDB and finishing before the sun burns out. Use with care.
If you need a gem for a certain purpose, be sure to check this site. The rankings are determined by...
Localizing a non-trivial application can be a huge undertaking. This card will give you an overview over the many...
MySQL version 5.1 comes with an alternative, faster InnoDB implementation (called "InnoDB Plugin"). Switching is easy: Stop your mysqld with...
When requests arrive at the application servers simultaneously, weird things can happen. Sometimes, this can also happen if a user...
Using beginning_of_day or end_of_day on Date or DateTime objects in Rails 2.x applications will never...
An association defined with has_many :through will return the same record multiple times if multiple join models for the...
When talking to your MySQL server via a mysql shell, you can terminate queries by ; or \G -- the latter gives...
Usually you don't need to, but when you want to see which queries your MySQL server currently needs to...