On Ubuntu/Debian and other distributions using aptitude: sudo apt-get install libmysql-ruby libmysqlclient-dev Package libmysql-ruby has been phased out and replaced by ruby-mysql. This is where I found the solution. If the above command doesn’t work because libmysql-ruby cannot be found, the following should be sufficient: sudo apt-get install libmysqlclient-dev On Red Hat/CentOS and other distributions … Read more
You won’t always be able to simply generate the migration to already have the code you want. You can create an empty migration and then populate it with the code you need. You can find information about how to accomplish different tasks in a migration here: http://api.rubyonrails.org/classes/ActiveRecord/Migration.html More specifically, you can see how to drop … Read more
After some search for a solution it turns out the -dev package is needed, not just ruby1.8. So if you have ruby1.9.1 doing sudo apt-get install ruby1.9.1-dev or to install generic ruby version, use (as per @lamplightdev comment): sudo apt-get install ruby-dev should fix it. Try locate mkmf to see if the file is actually … Read more
The word “deployment” can have two meanings depending on the context. You are also confusing the roles of Apache/Nginx with the roles of other components. Historic note: This article was originally written on November 6, 2010, when the Ruby app server ecosystem was limited. I’ve updated this article on March 15 2013 with all the … Read more
Yes, ensure ensures that the code is always evaluated. That’s why it’s called ensure. So, it is equivalent to Java’s and C#’s finally. The general flow of begin/rescue/else/ensure/end looks like this: begin # something which might raise an exception rescue SomeExceptionClass => some_variable # code that deals with some exception rescue SomeOtherException => some_other_variable # … Read more
Had a similar problem; a pid file was blocking postgres from starting up. To fix it: $ rm /usr/local/var/postgres/postmaster.pid $ brew services restart postgresql and then all is well. UPDATE: For Apple M1 (Big Sur) users, do this instead: $ rm /opt/homebrew/var/postgres/postmaster.pid $ brew services restart postgresql
I know two ways to do this: This will reset your database and reload your current schema with all: rake db:reset db:migrate This will destroy your db and then create it and then migrate your current schema: rake db:drop db:create db:migrate All data will be lost in both scenarios.
So I found it out by myself. It is actually a pretty simple but powerful concept. It has to do with code reuse as in the example below. Basically, the idea is to extract common and / or context specific chunks of code in order to clean up the models and avoid them getting too … Read more
Rails has an except/except! method that returns the hash with those keys removed. If you’re already using Rails, there’s no sense in creating your own version of this. class Hash # Returns a hash that includes everything but the given keys. # hash = { a: true, b: false, c: nil} # hash.except(:c) # => … Read more
db:migrate runs (single) migrations that have not run yet. db:create creates the database db:drop deletes the database db:schema:load creates tables and columns within the existing database following schema.rb. This will delete existing data. db:setup does db:create, db:schema:load, db:seed db:reset does db:drop, db:setup db:migrate:reset does db:drop, db:create, db:migrate Typically, you would use db:migrate after having made … Read more