method

establish_connection

v4.0.2 - Show latest stable - 0 notes - Class: ConnectionHandling

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What's this?

establish_connection(spec = ENV["DATABASE_URL"]) public

Establishes the connection to the database. Accepts a hash as input where the :adapter key must be specified with the name of a database adapter (in lower-case) example for regular databases (MySQL, Postgresql, etc):

ActiveRecord::Base.establish_connection(
  adapter:  "mysql",
  host:     "localhost",
  username: "myuser",
  password: "mypass",
  database: "somedatabase"
)

Example for SQLite database:

ActiveRecord::Base.establish_connection(
  adapter:  "sqlite",
  database: "path/to/dbfile"
)

Also accepts keys as strings (for parsing from YAML for example):

ActiveRecord::Base.establish_connection(
  "adapter"  => "sqlite",
  "database" => "path/to/dbfile"
)

Or a URL:

ActiveRecord::Base.establish_connection(
  "postgres://myuser:mypass@localhost/somedatabase"
)

The exceptions AdapterNotSpecified, AdapterNotFound and ArgumentError may be returned on an error.

Show source

# File activerecord/lib/active_record/connection_handling.rb, line 37
    def establish_connection(spec = ENV["DATABASE_URL"])
      resolver = ConnectionAdapters::ConnectionSpecification::Resolver.new spec, configurations
      spec = resolver.spec

      unless respond_to?(spec.adapter_method)
        raise AdapterNotFound, "database configuration specifies nonexistent #{spec.config[:adapter]} adapter"
      end

      remove_connection
      connection_handler.establish_connection self, spec
    end

establish_connection

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