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Diffstat (limited to 'activerecord/lib/active_record/connection_adapters/column.rb')
| -rw-r--r-- | activerecord/lib/active_record/connection_adapters/column.rb | 268 |
1 files changed, 268 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/column.rb b/activerecord/lib/active_record/connection_adapters/column.rb new file mode 100644 index 0000000000..4e3d8a096f --- /dev/null +++ b/activerecord/lib/active_record/connection_adapters/column.rb @@ -0,0 +1,268 @@ +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 |