activerecord/lib/active_record/connection_adapters.rb
# frozen_string_literal: true
require "active_support/core_ext/string/filters"
module ActiveRecord
module ConnectionAdapters
extend ActiveSupport::Autoload
@adapters = {}
class << self
# Registers a custom database adapter.
#
# Can also be used to define aliases.
#
# == Example
#
# ActiveRecord::ConnectionAdapters.register("megadb", "MegaDB::ActiveRecordAdapter", "mega_db/active_record_adapter")
#
# ActiveRecord::ConnectionAdapters.register("mysql", "ActiveRecord::ConnectionAdapters::TrilogyAdapter", "active_record/connection_adapters/trilogy_adapter")
#
def register(name, class_name, path = class_name.underscore)
@adapters[name.to_s] = [class_name, path]
end
def resolve(adapter_name) # :nodoc:
# Require the adapter itself and give useful feedback about
# 1. Missing adapter gems.
# 2. Incorrectly registered adapters.
# 3. Adapter gems' missing dependencies.
class_name, path_to_adapter = @adapters[adapter_name.to_s]
unless class_name
# To provide better error messages for adapters expecting the pre-7.2 adapter registration API, we attempt
# to load the adapter file from the old location which was required by convention, and then raise an error
# describing how to upgrade the adapter to the new API.
legacy_adapter_path = "active_record/connection_adapters/#{adapter_name}_adapter"
legacy_adapter_connection_method_name = "#{adapter_name}_connection".to_sym
begin
require legacy_adapter_path
# If we reach here it means we found the found a file that may be the legacy adapter and should raise.
if ActiveRecord::ConnectionHandling.method_defined?(legacy_adapter_connection_method_name)
# If we find the connection method then we care certain it is a legacy adapter.
deprecation_message = <<~MSG.squish
Database configuration specifies '#{adapter_name}' adapter but that adapter has not been registered.
Rails 7.2 has changed the way Active Record database adapters are loaded. The adapter needs to be
updated to register itself rather than being loaded by convention.
Ensure that the adapter in the Gemfile is at the latest version. If it is, then the adapter may need to
be modified.
See:
https://api.rubyonrails.org/classes/ActiveRecord/ConnectionAdapters.html#method-c-register
MSG
exception_message = <<~MSG.squish
Database configuration specifies '#{adapter_name}' adapter but that adapter has not been registered.
Ensure that the adapter in the Gemfile is at the latest version. If it is, then the adapter may need to
be modified.
MSG
else
# If we do not find the connection method we are much less certain it is a legacy adapter. Even though the
# file exists in the location defined by convenntion, it does not necessarily mean that file is supposed
# to define the adapter the legacy way. So raise an error that explains both possibilities.
deprecation_message = <<~MSG.squish
Database configuration specifies nonexistent '#{adapter_name}' adapter.
Available adapters are: #{@adapters.keys.sort.join(", ")}.
Ensure that the adapter is spelled correctly in config/database.yml and that you've added the necessary
adapter gem to your Gemfile if it's not in the list of available adapters.
Rails 7.2 has changed the way Active Record database adapters are loaded. Ensure that the adapter in
the Gemfile is at the latest version. If it is up to date, the adapter may need to be modified.
See:
https://api.rubyonrails.org/classes/ActiveRecord/ConnectionAdapters.html#method-c-register
MSG
exception_message = <<~MSG.squish
Database configuration specifies nonexistent '#{adapter_name}' adapter.
Available adapters are: #{@adapters.keys.sort.join(", ")}.
Ensure that the adapter is spelled correctly in config/database.yml and that you've added the necessary
adapter gem to your Gemfile and that it is at its latest version. If it is up to date, the adapter may
need to be modified.
MSG
end
ActiveRecord.deprecator.warn(deprecation_message)
raise AdapterNotFound, exception_message
rescue LoadError => error
# The adapter was not found in the legacy location so fall through to the error handling for a missing adapter.
end
raise AdapterNotFound, <<~MSG.squish
Database configuration specifies nonexistent '#{adapter_name}' adapter.
Available adapters are: #{@adapters.keys.sort.join(", ")}.
Ensure that the adapter is spelled correctly in config/database.yml and that you've added the necessary
adapter gem to your Gemfile if it's not in the list of available adapters.
MSG
end
unless Object.const_defined?(class_name)
begin
require path_to_adapter
rescue LoadError => error
# We couldn't require the adapter itself.
if error.path == path_to_adapter
# We can assume here that a non-builtin adapter was specified and the path
# registered by the adapter gem is incorrect.
raise LoadError, "Error loading the '#{adapter_name}' Active Record adapter. Ensure that the path registered by the adapter gem is correct. #{error.message}", error.backtrace
else
# Bubbled up from the adapter require. Prefix the exception message
# with some guidance about how to address it and reraise.
raise LoadError, "Error loading the '#{adapter_name}' Active Record adapter. Missing a gem it depends on? #{error.message}", error.backtrace
end
end
end
begin
Object.const_get(class_name)
rescue NameError => error
raise AdapterNotFound, "Could not load the #{class_name} Active Record adapter (#{error.message})."
end
end
end
register "sqlite3", "ActiveRecord::ConnectionAdapters::SQLite3Adapter", "active_record/connection_adapters/sqlite3_adapter"
register "mysql2", "ActiveRecord::ConnectionAdapters::Mysql2Adapter", "active_record/connection_adapters/mysql2_adapter"
register "trilogy", "ActiveRecord::ConnectionAdapters::TrilogyAdapter", "active_record/connection_adapters/trilogy_adapter"
register "postgresql", "ActiveRecord::ConnectionAdapters::PostgreSQLAdapter", "active_record/connection_adapters/postgresql_adapter"
eager_autoload do
autoload :AbstractAdapter
end
autoload :Column
autoload :PoolConfig
autoload :PoolManager
autoload :SchemaCache
autoload :BoundSchemaReflection, "active_record/connection_adapters/schema_cache"
autoload :SchemaReflection, "active_record/connection_adapters/schema_cache"
autoload :Deduplicable
autoload_at "active_record/connection_adapters/abstract/schema_definitions" do
autoload :IndexDefinition
autoload :ColumnDefinition
autoload :ChangeColumnDefinition
autoload :ChangeColumnDefaultDefinition
autoload :ForeignKeyDefinition
autoload :CheckConstraintDefinition
autoload :TableDefinition
autoload :Table
autoload :AlterTable
autoload :ReferenceDefinition
end
autoload_under "abstract" do
autoload :SchemaStatements
autoload :DatabaseStatements
autoload :DatabaseLimits
autoload :Quoting
autoload :ConnectionHandler
autoload :QueryCache
autoload :Savepoints
end
autoload_at "active_record/connection_adapters/abstract/connection_pool" do
autoload :ConnectionPool
autoload :NullPool
end
autoload_at "active_record/connection_adapters/abstract/transaction" do
autoload :TransactionManager
autoload :NullTransaction
autoload :RealTransaction
autoload :SavepointTransaction
autoload :TransactionState
end
end
end