diff options
| -rwxr-xr-x | activerecord/lib/active_record/connection_adapters/abstract_adapter.rb | 18 |
1 files changed, 11 insertions, 7 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb index 6c96ed5b35..2132b59fac 100755 --- a/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb +++ b/activerecord/lib/active_record/connection_adapters/abstract_adapter.rb @@ -13,15 +13,19 @@ require 'active_record/connection_adapters/abstract/query_cache' module ActiveRecord module ConnectionAdapters # :nodoc: + # ActiveRecord supports multiple database systems. AbstractAdapter and + # related classes form the abstraction layer which makes this possible. + # An AbstractAdapter represents a connection to a database, and provides an + # abstract interface for database-specific functionality such as establishing + # a connection, escaping values, building the right SQL fragments for ':offset' + # and ':limit' options, etc. + # # All the concrete database adapters follow the interface laid down in this class. - # You can use this interface directly by borrowing the database connection from the Base with - # Base.connection. + # ActiveRecord::Base.connection returns an AbstractAdapter object, which + # you can use. # - # Most of the methods in the adapter are useful during migrations. Most - # notably, SchemaStatements#create_table, SchemaStatements#drop_table, - # SchemaStatements#add_index, SchemaStatements#remove_index, - # SchemaStatements#add_column, SchemaStatements#change_column and - # SchemaStatements#remove_column are very useful. + # Most of the methods in the adapter are useful during migrations. Most + # notably, the instance methods provided by SchemaStatement are very useful. class AbstractAdapter include Quoting, DatabaseStatements, SchemaStatements include QueryCache |