No connection pool with id primary found

Question

I just installed Ruby on Rails v5 but when I run the rails server and go to browser, this error comes up?

def retrieve_connection(spec_name) #:nodoc:
    pool = retrieve_connection_pool(spec_name)
    raise ConnectionNotEstablished, "No connection pool with id #{spec_name} found." unless pool
    conn = pool.connection
    raise ConnectionNotEstablished, "No connection for #{spec_name} in connection pool" unless conn
    conn

Answer 1

I had this problem myself; one or more of the databases you are using on your database.yml files are currently not installed.

---

Since you mentioned you "just" installed RoRv5, That Database is most likely sqlite3, make sure u are including gem 'sqlite3' on your gemfile then

run: gem install sqlite3

If you are using a different database, run the corresponding gem install command.