add initial ActiveRecord driver

lib/active_record/connection_adapters/mysql2_adapter.rb

@@ -0,0 +1,160 @@
+# encoding: utf-8
+
+require 'mysql2' unless defined? Mysql2
+require 'active_record/connection_adapters/mysql_adapter'
+
+module ActiveRecord
+  class Base
+    def self.mysql2_connection(config)
+      client = Mysql2::Client.new(config.symbolize_keys)
+      options = [config[:host], config[:username], config[:password], config[:database], config[:port], config[:socket], 0]
+      ConnectionAdapters::Mysql2Adapter.new(client, logger, options, config)
+    end
+  end
+
+  module ConnectionAdapters
+    class Mysql2Column < MysqlColumn
+      # Returns the Ruby class that corresponds to the abstract data type.
+      def klass
+        case type
+          when :integer       then Fixnum
+          when :float         then Float
+          when :decimal       then BigDecimal
+          when :datetime      then Time
+          when :date          then Time
+          when :timestamp     then Time
+          when :time          then Time
+          when :text, :string then String
+          when :binary        then String
+          when :boolean       then Object
+        end
+      end
+
+      def type_cast(value)
+        if type == :boolean
+          self.class.value_to_boolean(value)
+        else
+          value
+        end
+      end
+      
+      def type_cast_code(var_name)
+        nil
+      end
+    end
+
+    class Mysql2Adapter < MysqlAdapter
+      PRIMARY = "PRIMARY".freeze
+
+      # QUOTING ==================================================
+      def quote_string(string)
+        @connection.escape(string)
+      end
+
+      # CONNECTION MANAGEMENT ====================================
+
+      def active?
+        @connection.query 'select 1'
+        true
+      rescue Mysql2::Error
+        false
+      end
+
+      def reconnect!
+        reset!
+      end
+
+      def disconnect!
+        @connection = nil
+      end
+
+      def reset!
+        @connection = Mysql2::Client.new(@config)
+      end
+
+      # DATABASE STATEMENTS ======================================
+
+      def select_values(sql, name = nil)
+        result = select_rows(sql, name)
+        result.map { |row| row.values.first }
+      end
+
+      def select_rows(sql, name = nil)
+        select(sql, name)
+      end
+
+      def insert_sql(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil)
+        super sql, name
+        id_value || @connection.last_id
+      end
+      alias :create :insert_sql
+
+      # SCHEMA STATEMENTS ========================================
+
+      def tables(name = nil)
+        tables = []
+        execute("SHOW TABLES", name).each(:symbolize_keys => true) do |field|
+          tables << field.values.first
+        end
+        tables
+      end
+
+      def indexes(table_name, name = nil)
+        indexes = []
+        current_index = nil
+        result = execute("SHOW KEYS FROM #{quote_table_name(table_name)}", name)
+        result.each(:symbolize_keys => true) do |row|
+          if current_index != row[:Key_name]
+            next if row[:Key_name] == PRIMARY # skip the primary key
+            current_index = row[:Key_name]
+            indexes << IndexDefinition.new(row[:Table], row[:Key_name], row[:Non_unique] == 0, [])
+          end
+
+          indexes.last.columns << row[:Column_name]
+        end
+        indexes
+      end
+
+      def columns(table_name, name = nil)
+        sql = "SHOW FIELDS FROM #{quote_table_name(table_name)}"
+        columns = []
+        result = execute(sql, :skip_logging)
+        result.each(:symbolize_keys => true) { |field|
+          columns << Mysql2Column.new(field[:Field], field[:Default], field[:Type], field[:Null] == "YES")
+        }
+        columns
+      end
+
+      def show_variable(name)
+        variables = select_all("SHOW VARIABLES LIKE '#{name}'")
+        variables.first[:Value] unless variables.empty?
+      end
+
+      def pk_and_sequence_for(table)
+        keys = []
+        result = execute("describe #{quote_table_name(table)}")
+        result.each(:symbolize_keys) do |row|
+          keys << row[:Field] if row[:Key] == "PRI"
+        end
+        keys.length == 1 ? [keys.first, nil] : nil
+      end
+
+      private
+        def connect
+          # no-op
+        end
+
+        def select(sql, name = nil)
+          execute(sql, name).to_a
+        end
+
+        def supports_views?
+          version[0] >= 5
+        end
+
+        def version
+          @version ||= @connection.info[:version].scan(/^(\d+)\.(\d+)\.(\d+)/).flatten.map { |v| v.to_i }
+        end
+    end
+  end
+end

spec/active_record/active_record_spec.rb

@@ -0,0 +1,23 @@
+# encoding: UTF-8
+require File.expand_path(File.dirname(__FILE__) + '/../spec_helper.rb')
+require 'active_record'
+require 'active_record/connection_adapters/mysql2_adapter'
+
+describe ActiveRecord::ConnectionAdapters::Mysql2Adapter do
+  it "should be able to connect" do
+    lambda {
+      ActiveRecord::Base.establish_connection(:adapter => 'mysql2')
+    }.should_not raise_error(Mysql2::Error)
+  end
+  
+  context "once connected" do
+    before(:each) do
+      @connection = ActiveRecord::Base.connection
+    end
+
+    it "should be able to execute a raw query" do
+      @connection.execute("SELECT 1 as one").first['one'].should eql(1)
+      @connection.execute("SELECT NOW() as n").first['n'].class.should eql(Time)
+    end
+  end
+end