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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
# Instantiates a new column in the table.
#
# +name+ is the column's name, as in <tt><b>supplier_id</b> int(11)</tt>.
# +default+ is the type-casted default value, such as <tt>sales_stage varchar(20) default <b>'new'</b></tt>.
# +sql_type+ is only used to extract the column's length, if necessary. For example, <tt>company_name varchar(<b>60</b>)</tt>.
# +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?
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)
if value.nil? then return nil end
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 string_to_time(value)
when :timestamp then string_to_time(value)
when :time then string_to_dummy_time(value)
when :date then string_to_date(value)
when :binary then binary_to_string(value)
when :boolean then value == true or (value =~ /^t(rue)?$/i) == 0 or value.to_s == '1'
else value
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 string_to_binary(value)
value
end
# Used to convert from BLOBs to Strings
def binary_to_string(value)
value
end
private
def 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 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 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
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 = "#{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:
# <tt>:primary_key</tt>, <tt>:string</tt>, <tt>:text</tt>,
# <tt>:integer</tt>, <tt>:float</tt>, <tt>:datetime</tt>,
# <tt>:timestamp</tt>, <tt>:time</tt>, <tt>:date</tt>,
# <tt>:binary</tt>, <tt>:boolean</tt>.
#
# Available options are (none of these exists by default):
# * <tt>:limit</tt>:
# Requests a maximum column length (<tt>:string</tt>, <tt>:text</tt>,
# <tt>:binary</tt> or <tt>:integer</tt> columns only)
# * <tt>:default</tt>:
# 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.
# * <tt>:null</tt>:
# Allows or disallows +NULL+ values in the column. This option could
# have been named <tt>:null_allowed</tt>.
#
# This method returns <tt>self</tt>.
#
# ===== 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
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