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RAILS_ENV | = | -> { (Rails.env if defined?(Rails.env)) || ENV["RAILS_ENV"] || ENV["RACK_ENV"] } |
DEFAULT_ENV | = | -> { RAILS_ENV.call || "default_env" } |
[W] | connection_specification_name |
Returns true
if Active Record is connected.
Returns the connection currently associated with the class. This can also be used to “borrow” the connection to do database work unrelated to any of the specific Active Records.
Returns the configuration of the associated connection as a hash:
ActiveRecord::Base.connection_config
# => {pool: 5, timeout: 5000, database: "db/development.sqlite3", adapter: "sqlite3"}
Please use only for reading.
Return the specification id from this class otherwise look it up in the parent.
# File activerecord/lib/active_record/connection_handling.rb, line 98 def connection_specification_name if !defined?(@connection_specification_name) || @connection_specification_name.nil? return self == Base ? "primary" : superclass.connection_specification_name end @connection_specification_name end
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: "mysql2",
host: "localhost",
username: "myuser",
password: "mypass",
database: "somedatabase"
)
Example for SQLite database:
ActiveRecord::Base.establish_connection(
adapter: "sqlite3",
database: "path/to/dbfile"
)
Also accepts keys as strings (for parsing from YAML for example):
ActiveRecord::Base.establish_connection(
"adapter" => "sqlite3",
"database" => "path/to/dbfile"
)
Or a URL:
ActiveRecord::Base.establish_connection(
"postgres://myuser:mypass@localhost/somedatabase"
)
In case ActiveRecord::Base.configurations is set (Rails automatically loads the contents of config/database.yml into it), a symbol can also be given as argument, representing a key in the configuration hash:
ActiveRecord::Base.establish_connection(:production)
The exceptions AdapterNotSpecified,
AdapterNotFound and
ArgumentError
may be returned on an error.
# File activerecord/lib/active_record/connection_handling.rb, line 47 def establish_connection(spec = nil) raise RuntimeError, "Anonymous class is not allowed." unless name spec ||= DEFAULT_ENV.call.to_sym resolver = ConnectionAdapters::ConnectionSpecification::Resolver.new configurations # TODO: uses name on establish_connection, for backwards compatibility spec = resolver.spec(spec, self == Base ? "primary" : name) unless respond_to?(spec.adapter_method) raise AdapterNotFound, "database configuration specifies nonexistent #{spec.config[:adapter]} adapter" end remove_connection(spec.name) self.connection_specification_name = spec.name connection_handler.establish_connection spec end
# File activerecord/lib/active_record/connection_handling.rb, line 136 def remove_connection(name = nil) name ||= @connection_specification_name if defined?(@connection_specification_name) # if removing a connection that have a pool, we reset the # connection_specification_name so it will use the parent # pool. if connection_handler.retrieve_connection_pool(name) self.connection_specification_name = nil end connection_handler.remove_connection(name) end