Question

I finally got a MySQL database hooked up to a Rails 3.2 app after spending half the day figuring it out.

What I don’t understand though is how Rails knows where to find the database?

With the default Sqlite3 it’s easy enough in that it’s embedded in the app so it’s just a matter of specifying the path in the database.yml (db/devlopment.sqlite3).

But, when it’s MySQL, I thought I’d have to specify the path of the database I’d created from the MySQL command line. Turns out I don’t have to, all I have to do is give the name of the database and user login credentials.

So when I run a migration in Rails, how does it know where the database is?

Answer 1

That’s called a reasonable default. Take a look in your database.yml file, you might find a line like this:

socket = socket: /tmp/mysql.sock

AFAIK, if that’s not explicitly there, it is used as the default in the absence of other parameters (such as host and port).