instance method gem_for_database

# File railties/lib/rails/generators/app_base.rb, line 156
      def gem_for_database
        # %w( mysql oracle postgresql sqlite3 frontbase ibm_db sqlserver jdbcmysql jdbcsqlite3 jdbcpostgresql )
        case options[:database]
        when "oracle"     then "ruby-oci8"
        when "postgresql" then "pg"
        when "frontbase"  then "ruby-frontbase"
        when "mysql"      then "mysql2"
        when "sqlserver"  then "activerecord-sqlserver-adapter"
        when "jdbcmysql"      then "activerecord-jdbcmysql-adapter"
        when "jdbcsqlite3"    then "activerecord-jdbcsqlite3-adapter"
        when "jdbcpostgresql" then "activerecord-jdbcpostgresql-adapter"
        when "jdbc"           then "activerecord-jdbc-adapter"
        else options[:database]
        end
      end