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 <tt>supplier_id</tt> in <tt>supplier_id int(11)</tt>.
# +default+ is the type-casted default value, such as +new+ in <tt>sales_stage varchar(20) default 'new'</tt>.
# +sql_type+ is used to extract the column's length, if necessary. For example +60+ in
# <tt>company_name varchar(60)</tt>.
# It will be mapped to one of the standard Rails SQL types in the <tt>type</tt> 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
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
