require 'set' module ActiveRecord # :stopdoc: module ConnectionAdapters # An abstract definition of a column in a table. class Column TRUE_VALUES = [true, 1, '1', 't', 'T', 'true', 'TRUE'].to_set FALSE_VALUES = [false, 0, '0', 'f', 'F', 'false', 'FALSE'].to_set module Format ISO_DATE = /\A(\d{4})-(\d\d)-(\d\d)\z/ ISO_DATETIME = /\A(\d{4})-(\d\d)-(\d\d) (\d\d):(\d\d):(\d\d)(\.\d+)?\z/ end attr_reader :name, :default, :type, :limit, :null, :sql_type, :precision, :scale attr_accessor :primary, :coder alias :encoded? :coder # Instantiates a new column in the table. # # +name+ is the column's name, such as supplier_id in supplier_id int(11). # +default+ is the type-casted default value, such as +new+ in sales_stage varchar(20) default 'new'. # +sql_type+ is used to extract the column's length, if necessary. For example +60+ in # company_name varchar(60). # It will be mapped to one of the standard Rails SQL types in the type attribute. # +null+ determines if this column allows +NULL+ values. def initialize(name, default, sql_type = nil, null = true) @name = name @sql_type = sql_type @null = null @limit = extract_limit(sql_type) @precision = extract_precision(sql_type) @scale = extract_scale(sql_type) @type = simplified_type(sql_type) @default = extract_default(default) @primary = nil @coder = nil end # Returns +true+ if the column is either of type string or text. def text? type == :string || type == :text end # Returns +true+ if the column is either of type integer, float or decimal. def number? type == :integer || type == :float || type == :decimal end def has_default? !default.nil? end # 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, :timestamp, :time then Time when :date then Date when :text, :string, :binary then String when :boolean then Object end end # Casts value (which is a String) to an appropriate instance. def type_cast(value) return nil if value.nil? return coder.load(value) if encoded? klass = self.class case type when :string, :text then value when :integer then value.to_i rescue value ? 1 : 0 when :float then value.to_f when :decimal then klass.value_to_decimal(value) when :datetime, :timestamp then klass.string_to_time(value) when :time then klass.string_to_dummy_time(value) when :date then klass.string_to_date(value) when :binary then klass.binary_to_string(value) when :boolean then klass.value_to_boolean(value) else value end end def type_cast_code(var_name) klass = self.class.name case type when :string, :text then var_name when :integer then "(#{var_name}.to_i rescue #{var_name} ? 1 : 0)" when :float then "#{var_name}.to_f" when :decimal then "#{klass}.value_to_decimal(#{var_name})" when :datetime, :timestamp then "#{klass}.string_to_time(#{var_name})" when :time then "#{klass}.string_to_dummy_time(#{var_name})" when :date then "#{klass}.string_to_date(#{var_name})" when :binary then "#{klass}.binary_to_string(#{var_name})" when :boolean then "#{klass}.value_to_boolean(#{var_name})" else var_name end end # Returns the human name of the column name. # # ===== Examples # Column.new('sales_stage', ...).human_name # => 'Sales stage' def human_name Base.human_attribute_name(@name) end def extract_default(default) type_cast(default) end # Used to convert from Strings to BLOBs def string_to_binary(value) self.class.string_to_binary(value) end class << self # Used to convert from Strings to BLOBs def string_to_binary(value) value end # Used to convert from BLOBs to Strings def binary_to_string(value) value end def string_to_date(string) return string unless string.is_a?(String) return nil if string.empty? fast_string_to_date(string) || fallback_string_to_date(string) end def string_to_time(string) return string unless string.is_a?(String) return nil if string.empty? fast_string_to_time(string) || fallback_string_to_time(string) end def string_to_dummy_time(string) return string unless string.is_a?(String) return nil if string.empty? string_to_time "2000-01-01 #{string}" end # convert something to a boolean def value_to_boolean(value) if value.is_a?(String) && value.blank? nil else TRUE_VALUES.include?(value) end end # convert something to a BigDecimal def value_to_decimal(value) # Using .class is faster than .is_a? and # subclasses of BigDecimal will be handled # in the else clause if value.class == BigDecimal value elsif value.respond_to?(:to_d) value.to_d else value.to_s.to_d end end protected # '0.123456' -> 123456 # '1.123456' -> 123456 def microseconds(time) ((time[:sec_fraction].to_f % 1) * 1_000_000).to_i end def new_date(year, mon, mday) if year && year != 0 Date.new(year, mon, mday) rescue nil end end def new_time(year, mon, mday, hour, min, sec, microsec) # Treat 0000-00-00 00:00:00 as nil. return nil if year.nil? || (year == 0 && mon == 0 && mday == 0) Time.time_with_datetime_fallback(Base.default_timezone, year, mon, mday, hour, min, sec, microsec) rescue nil end def fast_string_to_date(string) if string =~ Format::ISO_DATE new_date $1.to_i, $2.to_i, $3.to_i end end # Doesn't handle time zones. def fast_string_to_time(string) if string =~ Format::ISO_DATETIME microsec = ($7.to_f * 1_000_000).to_i new_time $1.to_i, $2.to_i, $3.to_i, $4.to_i, $5.to_i, $6.to_i, microsec end end def fallback_string_to_date(string) new_date(*::Date._parse(string, false).values_at(:year, :mon, :mday)) end def fallback_string_to_time(string) time_hash = Date._parse(string) time_hash[:sec_fraction] = microseconds(time_hash) new_time(*time_hash.values_at(:year, :mon, :mday, :hour, :min, :sec, :sec_fraction)) end end private def extract_limit(sql_type) $1.to_i if sql_type =~ /\((.*)\)/ end def extract_precision(sql_type) $2.to_i if sql_type =~ /^(numeric|decimal|number)\((\d+)(,\d+)?\)/i end def extract_scale(sql_type) case sql_type when /^(numeric|decimal|number)\((\d+)\)/i then 0 when /^(numeric|decimal|number)\((\d+)(,(\d+))\)/i then $4.to_i end end def simplified_type(field_type) case field_type when /int/i :integer when /float|double/i :float when /decimal|numeric|number/i extract_scale(field_type) == 0 ? :integer : :decimal when /datetime/i :datetime when /timestamp/i :timestamp when /time/i :time when /date/i :date when /clob/i, /text/i :text when /blob/i, /binary/i :binary when /char/i, /string/i :string when /boolean/i :boolean end end end end # :startdoc: end