require 'parsedate' module ActiveRecord module ConnectionAdapters #:nodoc: # An abstract definition of a column in a table. class Column attr_reader :name, :default, :type, :limit, :null attr_accessor :primary # Instantiates a new column in the table. # # +name+ is the column's name, as in supplier_id int(11). # +default+ is the type-casted default value, such as sales_stage varchar(20) default 'new'. # +sql_type+ is only used to extract the column's length, if necessary. For example, company_name varchar(60). # +null+ determines if this column allows +NULL+ values. def initialize(name, default, sql_type = nil, null = true) @name, @type, @null = name, simplified_type(sql_type), null # have to do this one separately because type_cast depends on #type @default = type_cast(default) @limit = extract_limit(sql_type) unless sql_type.nil? @primary = nil @text = [:string, :text].include? @type @number = [:float, :integer].include? @type end def text? @text end def number? @number 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 :datetime then Time when :date then Date when :timestamp then Time when :time then Time when :text, :string then String when :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? case type when :string then value when :text then value when :integer then value.to_i rescue value ? 1 : 0 when :float then value.to_f when :datetime then self.class.string_to_time(value) when :timestamp then self.class.string_to_time(value) when :time then self.class.string_to_dummy_time(value) when :date then self.class.string_to_date(value) when :binary then self.class.binary_to_string(value) when :boolean then self.class.value_to_boolean(value) else value end end def type_cast_code(var_name) case type when :string then nil when :text then nil when :integer then "(#{var_name}.to_i rescue #{var_name} ? 1 : 0)" when :float then "#{var_name}.to_f" when :datetime then "#{self.class.name}.string_to_time(#{var_name})" when :timestamp then "#{self.class.name}.string_to_time(#{var_name})" when :time then "#{self.class.name}.string_to_dummy_time(#{var_name})" when :date then "#{self.class.name}.string_to_date(#{var_name})" when :binary then "#{self.class.name}.binary_to_string(#{var_name})" when :boolean then "#{self.class.name}.value_to_boolean(#{var_name})" else nil 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 # Used to convert from Strings to BLOBs def self.string_to_binary(value) value end # Used to convert from BLOBs to Strings def self.binary_to_string(value) value end def self.string_to_date(string) return string unless string.is_a?(String) date_array = ParseDate.parsedate(string) # treat 0000-00-00 as nil Date.new(date_array[0], date_array[1], date_array[2]) rescue nil end def self.string_to_time(string) return string unless string.is_a?(String) time_array = ParseDate.parsedate(string)[0..5] # treat 0000-00-00 00:00:00 as nil Time.send(Base.default_timezone, *time_array) rescue nil end def self.string_to_dummy_time(string) return string unless string.is_a?(String) time_array = ParseDate.parsedate(string) # pad the resulting array with dummy date information time_array[0] = 2000; time_array[1] = 1; time_array[2] = 1; Time.send(Base.default_timezone, *time_array) rescue nil end # convert something to a boolean def self.value_to_boolean(value) return value if value==true || value==false case value.to_s.downcase when "true", "t", "1" then true else false end end private def extract_limit(sql_type) $1.to_i if sql_type =~ /\((.*)\)/ end def simplified_type(field_type) case field_type when /int/i :integer when /float|double|decimal|numeric/i :float 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 class IndexDefinition < Struct.new(:table, :name, :unique, :columns) #:nodoc: end class ColumnDefinition < Struct.new(:base, :name, :type, :limit, :default, :null) #:nodoc: def to_sql column_sql = "#{base.quote_column_name(name)} #{type_to_sql(type.to_sym, limit)}" add_column_options!(column_sql, :null => null, :default => default) column_sql end alias to_s :to_sql private def type_to_sql(name, limit) base.type_to_sql(name, limit) rescue name end def add_column_options!(sql, options) base.add_column_options!(sql, options.merge(:column => self)) end end # Represents a SQL table in an abstract way. # Columns are stored as ColumnDefinition in the #columns attribute. class TableDefinition attr_accessor :columns def initialize(base) @columns = [] @base = base end # Appends a primary key definition to the table definition. # Can be called multiple times, but this is probably not a good idea. def primary_key(name) column(name, native[:primary_key]) end # Returns a ColumnDefinition for the column with name +name+. def [](name) @columns.find {|column| column.name.to_s == name.to_s} end # Instantiates a new column for the table. # The +type+ parameter must be one of the following values: # :primary_key, :string, :text, # :integer, :float, :datetime, # :timestamp, :time, :date, # :binary, :boolean. # # Available options are (none of these exists by default): # * :limit: # Requests a maximum column length (:string, :text, # :binary or :integer columns only) # * :default: # The column's default value. You cannot explicitely set the default # value to +NULL+. Simply leave off this option if you want a +NULL+ # default value. # * :null: # Allows or disallows +NULL+ values in the column. This option could # have been named :null_allowed. # # This method returns self. # # ===== Examples # # Assuming def is an instance of TableDefinition # def.column(:granted, :boolean) # #=> granted BOOLEAN # # def.column(:picture, :binary, :limit => 2.megabytes) # #=> picture BLOB(2097152) # # def.column(:sales_stage, :string, :limit => 20, :default => 'new', :null => false) # #=> sales_stage VARCHAR(20) DEFAULT 'new' NOT NULL def column(name, type, options = {}) column = self[name] || ColumnDefinition.new(@base, name, type) column.limit = options[:limit] || native[type.to_sym][:limit] if options[:limit] or native[type.to_sym] column.default = options[:default] column.null = options[:null] @columns << column unless @columns.include? column self end # Returns a String whose contents are the column definitions # concatenated together. This string can then be pre and appended to # to generate the final SQL to create the table. def to_sql @columns * ', ' end private def native @base.native_database_types end end end end