I have encountered this in my Gemfile while learning ruby on rails:
group :development, :test do
gem 'sqlite3', '~> 1.4'
group :production do
gem 'pg'
So far I have understood that sqlite3 is not a production-ready database as it does not support multiple users to write the database at the same time. In this case, why don't we just use postgres in development?
There is no reason you can’t. It just requires additional configuration. It’s actually best practice to use the same database in development and production. SQLite is included for ease of use, and would probably fine for a lot of applications. But SQLite cannot be used on Heroku and some other hosting platforms. So you are better off setting up Postgres on your local machine for development in my opinion.
Related
I am trying to deploy a Rails project on Heroku. My Rails application uses mysql2.
I have tried using the taps gem but its not working. I get the following error when I run the command taps server mysql://root#localhost/heroku_ex tempuser tempass:
Failed to connect to database: Sequel::AdapterNotFound -> LoadError: cannot load such file -- mysql
Is there any way to deploy my application on Heroku? I would prefer to only use free add-ons if possible.
There are a few moving parts here.
First of all, Heroku doesn't support MySQL by default. If you want to use MySQL instead of PostgreSQL you will have to provision an add-on that provides it. There are currently at least two add-ons that provide MySQL or MariaDB¹ support with a free tier².
Next, Heroku doesn't run database servers on localhost. How can you handle different database configurations between your development machine and your Heroku server?
One strategy that is endorsed by Heroku is to store configuration in the environment. Following this model lets you alter your application's configuration by modifying environment variables instead of editing files. Luckily, Rails appears to override config/database.yml with configuration from the DATABASE_URL variable by default, so this approach should be a good fit.
Very often database add-ons will automatically set an environment variable for you. For example, the JawsDB Maria add-on sets JAWSDB_MARIA_URL when it is provisioned. This isn't the variable that Rails looks for, so you'll either have to tell Rails to look for JAWSDB_MARIA_URL instead of DATABASE_URL or manually set DATABASE_URL to contain the same URL that JawsDB provides in JAWSDB_MARIA_URL.
¹MariaDB is a fork of MySQL that aims to be fully-compatible.
²Note that the free tier may be quite limited, e.g. by only providing 5MB of storage. You may have to upgrade to a paid database tier as you continue to develop your application.
I have solved this by adding the pg gem in production and mysql2 in development environment.
group :development, :test do
gem 'mysql2'
end
group :production do
gem 'listen', '~> 3.0.5'
gem 'pg'
# Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
gem 'spring'
gem 'spring-watcher-listen', '~> 2.0.0'
end
I have about 3 apps on a Windows Server 2012 and all of them are different versions of rails. So far, I can run locally the app with the latest version of rails, but not the other two, which were deployed from Heroku. I wanted to make changes locally before I push them to Heroku but no luck. Is there any reference to that or is this even possible? thanks a lot!
Your problem is that you are trying to use sqlite with Heroku. Heroku requires using 'postgres' as the database
change the gemfile to the following
group :development do
gem 'sqlite3'
end
group :production do
gem 'pg'
end
And then change your database.yml file to this
adapter: postgresql
Hi I am about to deploy a rails app (onto heroku) I made and wanted to know what the procedure is. I know you have to change the database by changing gem 'sqlite3' to gem 'pg' but after I did that and went on my localhost:3000 it gives me the error:
ActiveRecord::ConnectionNotEstablished
What else am I missing?
You don't need to change gem. Database used in application on heroku default is postgres. Keep gem 'sqlite3' and add this in your Gemfile:
group :production do
gem "pg", "0.14.0"
end
I have a little Rails app that is deployed on Heroku. They require a Postgres database, which was not a problem to switch from SQLite3 on their side, but now I can't develop locally without pushing to Heroku every time I want to see changes. I downloaded and installed all of the Postgres assets including the little MenuBar app that keeps a server running and have been all over documentation. Any help?
try this
write in your gemfile
group :development do
gem "sqlite3"
end
group :production do
gem 'pg'
end
when you are working on development mode then it used sqlite3
and while you are working on production mode then it used pg
I am developing on an open source rails application and as a rails 3 project, it includes a Gemfile. The application is also dependent on a database adapter for active record. I can specify a specific adapter (like gem 'sqlite3') within the Gemfile but this is not what I want to do. I advertise the app as beeing compatible with all the adapters active record is compatible with. Is there any way to specify that the app depends on a single database adapter (out of a selection) but that one is sufficient? Something like
any_of do
gem 'sqlite'
gem 'mysql'
etc.
end
Thanks for any help or suggestions how to approach the problem differently.
I just recently installed something that generated an error, until I realized how they handled this.
group :postgresql do
gem 'pg'
end
group :mysql do
gem 'mysql2'
end
and then when you run bundler:
bundle install --without postgresql