def schema(format = :activerecord, table_only = false)
      schema_method_name = schema_name(format)
      send(schema_method_name, table_only)
    rescue NameError
      raise ArgumentError, ":#{format} is not a valid schema. Valid schemas are: #{FORMATS.join(', ')}."
    end
def schema(format = :activerecord, table_only = false)
      schema_method_name = schema_name(format)
      send(schema_method_name, table_only)
    rescue NameError
      raise ArgumentError, ":#{format} is not a valid schema. Valid schemas are: #{FORMATS.join(', ')}."
    end
Generate an ActiveRecord::Schema

 xBase data types are converted to generic types as follows:
 - Number columns with no decimals are converted to :integer
 - Number columns with decimals are converted to :float
 - Date columns are converted to :datetime
 - Logical columns are converted to :boolean
 - Memo columns are converted to :text
 - Character columns are converted to :string and the :limit option is set
   to the length of the character column

 Example:
   create_table "mydata" do |t|
     t.column :name, :string, :limit => 30
     t.column :last_update, :datetime
     t.column :is_active, :boolean
     t.column :age, :integer
     t.column :notes, :text
   end

 @param [Symbol] format Valid options are :activerecord and :json
 @return [String]