method

connects_to

v6.1.7.7 - Show latest stable - 0 notes - Class: ConnectionHandling

1.0.0
1.1.6
1.2.6
2.0.3
2.1.0
2.2.1
2.3.8
3.0.0
3.0.9
3.1.0
3.2.1
3.2.8
3.2.13
4.0.2
4.1.8
4.2.1
4.2.7
4.2.9
5.0.0.1
5.1.7
5.2.3
6.0.0 (0)
6.1.3.1 (38)
6.1.7.7 (0)
7.0.0 (0)
7.1.3.2 (-5)
What's this?

connects_to(database: {}, shards: {}) public

Connects a model to the databases specified. The database keyword takes a hash consisting of a role and a database_key.

This will create a connection handler for switching between connections, look up the config hash using the database_key and finally establishes a connection to that config.

class AnimalsModel < ApplicationRecord
  self.abstract_class = true

  connects_to database: { writing: :primary, reading: :primary_replica }
end

connects_to also supports horizontal sharding. The horizontal sharding API also supports read replicas. Connect a model to a list of shards like this:

class AnimalsModel < ApplicationRecord
  self.abstract_class = true

  connects_to shards: {
    default: { writing: :primary, reading: :primary_replica },
    shard_two: { writing: :primary_shard_two, reading: :primary_shard_replica_two }
  }
end

Returns an array of database connections.

Show source

# File activerecord/lib/active_record/connection_handling.rb, line 81
    def connects_to(database: {}, shards: {})
      raise NotImplementedError, "`connects_to` can only be called on ActiveRecord::Base or abstract classes" unless self == Base || abstract_class?

      if database.present? && shards.present?
        raise ArgumentError, "`connects_to` can only accept a `database` or `shards` argument, but not both arguments."
      end

      connections = []

      database.each do |role, database_key|
        db_config, owner_name = resolve_config_for_connection(database_key)
        handler = lookup_connection_handler(role.to_sym)

        self.connection_class = true
        connections << handler.establish_connection(db_config, owner_name: owner_name, role: role)
      end

      shards.each do |shard, database_keys|
        database_keys.each do |role, database_key|
          db_config, owner_name = resolve_config_for_connection(database_key)
          handler = lookup_connection_handler(role.to_sym)

          self.connection_class = true
          connections << handler.establish_connection(db_config, owner_name: owner_name, role: role, shard: shard.to_sym)
        end
      end

      connections
    end

connects_to

Related methods

Flowdock - Team Inbox With Chat