Load database adapters on demand. Eliminates config.connection_adapters and RAILS_CONNECTION_ADAPTERS. Closes #8456.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@6833 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

1 files changed, 34 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
new file mode 100644
index 0000000000..0827f61db4
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb
@@ -0,0 +1,34 @@
+require 'active_record/connection_adapters/sqlite_adapter'
+
+module ActiveRecord
+  class Base
+    # sqlite3 adapter reuses sqlite_connection.
+    def self.sqlite3_connection(config) # :nodoc:
+      parse_sqlite_config!(config)
+
+      unless self.class.const_defined?(:SQLite3)
+        require_library_or_gem(config[:adapter])
+      end
+
+      db = SQLite3::Database.new(
+        config[:database],
+        :results_as_hash => true,
+        :type_translation => false
+      )
+
+      db.busy_timeout(config[:timeout]) unless config[:timeout].nil?
+
+      ConnectionAdapters::SQLite3Adapter.new(db, logger)
+    end
+  end
+
+  module ConnectionAdapters #:nodoc:
+    class SQLite3Adapter < SQLiteAdapter # :nodoc:
+      def table_structure(table_name)
+        returning structure = @connection.table_info(table_name) do
+          raise(ActiveRecord::StatementInvalid, "Could not find table '#{table_name}'") if structure.empty?
+        end
+      end
+    end
+  end
+end