Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
Fetching contributors…

Cannot retrieve contributors at this time

723 lines (653 sloc) 28.141 kb
require 'date'
require 'set'
require 'bigdecimal'
require 'bigdecimal/util'
module ActiveRecord
module ConnectionAdapters #:nodoc:
# 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
# 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 only used to extract the column's length, if necessary. For example +60+ in <tt>company_name varchar(60)</tt>.
# +null+ determines if this column allows +NULL+ values.
def initialize(name, default, sql_type = nil, null = true)
@name, @sql_type, @null = name, sql_type, null
@limit, @precision, @scale = extract_limit(sql_type), extract_precision(sql_type), extract_scale(sql_type)
@type = simplified_type(sql_type)
@default = extract_default(default)
@primary = 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 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 :decimal then self.class.value_to_decimal(value)
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 :decimal then "#{self.class.name}.value_to_decimal(#{var_name})"
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
def extract_default(default)
type_cast(default)
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
class IndexDefinition < Struct.new(:table, :name, :unique, :columns, :lengths) #:nodoc:
end
# Abstract representation of a column definition. Instances of this type
# are typically created by methods in TableDefinition, and added to the
# +columns+ attribute of said TableDefinition object, in order to be used
# for generating a number of table creation or table changing SQL statements.
class ColumnDefinition < Struct.new(:base, :name, :type, :limit, :precision, :scale, :default, :null) #:nodoc:
def sql_type
base.type_to_sql(type.to_sym, limit, precision, scale) rescue type
end
def to_sql
column_sql = "#{base.quote_column_name(name)} #{sql_type}"
column_options = {}
column_options[:null] = null unless null.nil?
column_options[:default] = default unless default.nil?
add_column_options!(column_sql, column_options) unless type.to_sym == :primary_key
column_sql
end
private
def add_column_options!(sql, options)
base.add_column_options!(sql, options.merge(:column => self))
end
end
# Represents the schema of an SQL table in an abstract way. This class
# provides methods for manipulating the schema representation.
#
# Inside migration files, the +t+ object in +create_table+ and
# +change_table+ is actually of this type:
#
# class SomeMigration < ActiveRecord::Migration
# def self.up
# create_table :foo do |t|
# puts t.class # => "ActiveRecord::ConnectionAdapters::TableDefinition"
# end
# end
#
# def self.down
# ...
# end
# end
#
# The table definitions
# The Columns are stored as a ColumnDefinition in the +columns+ attribute.
class TableDefinition
# An array of ColumnDefinition objects, representing the column changes
# that have been defined.
attr_accessor :columns
def initialize(base)
@columns = []
@base = base
end
#Handles non supported datatypes - e.g. XML
def method_missing(symbol, *args)
if symbol.to_s == 'xml'
xml_column_fallback(args)
end
end
def xml_column_fallback(*args)
case @base.adapter_name.downcase
when 'sqlite', 'mysql'
options = args.extract_options!
column(args[0], :text, options)
end
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, :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 is normally one of the migrations native types,
# which is one of the following:
# <tt>:primary_key</tt>, <tt>:string</tt>, <tt>:text</tt>,
# <tt>:integer</tt>, <tt>:float</tt>, <tt>:decimal</tt>,
# <tt>:datetime</tt>, <tt>:timestamp</tt>, <tt>:time</tt>,
# <tt>:date</tt>, <tt>:binary</tt>, <tt>:boolean</tt>.
#
# You may use a type not in this list as long as it is supported by your
# database (for example, "polygon" in MySQL), but this will not be database
# agnostic and should usually be avoided.
#
# Available options are (none of these exists by default):
# * <tt>:limit</tt> -
# Requests a maximum column length. This is number of characters for <tt>:string</tt> and <tt>:text</tt> columns and number of bytes for :binary and :integer columns.
# * <tt>:default</tt> -
# The column's default value. Use nil for NULL.
# * <tt>:null</tt> -
# Allows or disallows +NULL+ values in the column. This option could
# have been named <tt>:null_allowed</tt>.
# * <tt>:precision</tt> -
# Specifies the precision for a <tt>:decimal</tt> column.
# * <tt>:scale</tt> -
# Specifies the scale for a <tt>:decimal</tt> column.
#
# For clarity's sake: the precision is the number of significant digits,
# while the scale is the number of digits that can be stored following
# the decimal point. For example, the number 123.45 has a precision of 5
# and a scale of 2. A decimal with a precision of 5 and a scale of 2 can
# range from -999.99 to 999.99.
#
# Please be aware of different RDBMS implementations behavior with
# <tt>:decimal</tt> columns:
# * The SQL standard says the default scale should be 0, <tt>:scale</tt> <=
# <tt>:precision</tt>, and makes no comments about the requirements of
# <tt>:precision</tt>.
# * MySQL: <tt>:precision</tt> [1..63], <tt>:scale</tt> [0..30].
# Default is (10,0).
# * PostgreSQL: <tt>:precision</tt> [1..infinity],
# <tt>:scale</tt> [0..infinity]. No default.
# * SQLite2: Any <tt>:precision</tt> and <tt>:scale</tt> may be used.
# Internal storage as strings. No default.
# * SQLite3: No restrictions on <tt>:precision</tt> and <tt>:scale</tt>,
# but the maximum supported <tt>:precision</tt> is 16. No default.
# * Oracle: <tt>:precision</tt> [1..38], <tt>:scale</tt> [-84..127].
# Default is (38,0).
# * DB2: <tt>:precision</tt> [1..63], <tt>:scale</tt> [0..62].
# Default unknown.
# * Firebird: <tt>:precision</tt> [1..18], <tt>:scale</tt> [0..18].
# Default (9,0). Internal types NUMERIC and DECIMAL have different
# storage rules, decimal being better.
# * FrontBase?: <tt>:precision</tt> [1..38], <tt>:scale</tt> [0..38].
# Default (38,0). WARNING Max <tt>:precision</tt>/<tt>:scale</tt> for
# NUMERIC is 19, and DECIMAL is 38.
# * SqlServer?: <tt>:precision</tt> [1..38], <tt>:scale</tt> [0..38].
# Default (38,0).
# * Sybase: <tt>:precision</tt> [1..38], <tt>:scale</tt> [0..38].
# Default (38,0).
# * OpenBase?: Documentation unclear. Claims storage in <tt>double</tt>.
#
# This method returns <tt>self</tt>.
#
# == Examples
# # Assuming td is an instance of TableDefinition
# td.column(:granted, :boolean)
# # granted BOOLEAN
#
# td.column(:picture, :binary, :limit => 2.megabytes)
# # => picture BLOB(2097152)
#
# td.column(:sales_stage, :string, :limit => 20, :default => 'new', :null => false)
# # => sales_stage VARCHAR(20) DEFAULT 'new' NOT NULL
#
# td.column(:bill_gates_money, :decimal, :precision => 15, :scale => 2)
# # => bill_gates_money DECIMAL(15,2)
#
# td.column(:sensor_reading, :decimal, :precision => 30, :scale => 20)
# # => sensor_reading DECIMAL(30,20)
#
# # While <tt>:scale</tt> defaults to zero on most databases, it
# # probably wouldn't hurt to include it.
# td.column(:huge_integer, :decimal, :precision => 30)
# # => huge_integer DECIMAL(30)
#
# # Defines a column with a database-specific type.
# td.column(:foo, 'polygon')
# # => foo polygon
#
# == Short-hand examples
#
# Instead of calling +column+ directly, you can also work with the short-hand definitions for the default types.
# They use the type as the method name instead of as a parameter and allow for multiple columns to be defined
# in a single statement.
#
# What can be written like this with the regular calls to column:
#
# create_table "products", :force => true do |t|
# t.column "shop_id", :integer
# t.column "creator_id", :integer
# t.column "name", :string, :default => "Untitled"
# t.column "value", :string, :default => "Untitled"
# t.column "created_at", :datetime
# t.column "updated_at", :datetime
# end
#
# Can also be written as follows using the short-hand:
#
# create_table :products do |t|
# t.integer :shop_id, :creator_id
# t.string :name, :value, :default => "Untitled"
# t.timestamps
# end
#
# There's a short-hand method for each of the type values declared at the top. And then there's
# TableDefinition#timestamps that'll add created_at and +updated_at+ as datetimes.
#
# TableDefinition#references will add an appropriately-named _id column, plus a corresponding _type
# column if the <tt>:polymorphic</tt> option is supplied. If <tt>:polymorphic</tt> is a hash of options, these will be
# used when creating the <tt>_type</tt> column. So what can be written like this:
#
# create_table :taggings do |t|
# t.integer :tag_id, :tagger_id, :taggable_id
# t.string :tagger_type
# t.string :taggable_type, :default => 'Photo'
# end
#
# Can also be written as follows using references:
#
# create_table :taggings do |t|
# t.references :tag
# t.references :tagger, :polymorphic => true
# t.references :taggable, :polymorphic => { :default => 'Photo' }
# end
def column(name, type, options = {})
column = self[name] || ColumnDefinition.new(@base, name, type)
if options[:limit]
column.limit = options[:limit]
elsif native[type.to_sym].is_a?(Hash)
column.limit = native[type.to_sym][:limit]
end
column.precision = options[:precision]
column.scale = options[:scale]
column.default = options[:default]
column.null = options[:null]
@columns << column unless @columns.include? column
self
end
%w( string text integer float decimal datetime timestamp time date binary boolean ).each do |column_type|
class_eval <<-EOV
def #{column_type}(*args) # def string(*args)
options = args.extract_options! # options = args.extract_options!
column_names = args # column_names = args
#
column_names.each { |name| column(name, '#{column_type}', options) } # column_names.each { |name| column(name, 'string', options) }
end # end
EOV
end
# Appends <tt>:datetime</tt> columns <tt>:created_at</tt> and
# <tt>:updated_at</tt> to the table.
def timestamps(*args)
options = args.extract_options!
column(:created_at, :datetime, options)
column(:updated_at, :datetime, options)
end
def references(*args)
options = args.extract_options!
polymorphic = options.delete(:polymorphic)
args.each do |col|
column("#{col}_id", :integer, options)
column("#{col}_type", :string, polymorphic.is_a?(Hash) ? polymorphic : options) unless polymorphic.nil?
end
end
alias :belongs_to :references
# Returns a String whose contents are the column definitions
# concatenated together. This string can then be prepended and appended to
# to generate the final SQL to create the table.
def to_sql
@columns.map(&:to_sql) * ', '
end
private
def native
@base.native_database_types
end
end
# Represents a SQL table in an abstract way for updating a table.
# Also see TableDefinition and SchemaStatements#create_table
#
# Available transformations are:
#
# change_table :table do |t|
# t.column
# t.index
# t.timestamps
# t.change
# t.change_default
# t.rename
# t.references
# t.belongs_to
# t.string
# t.text
# t.integer
# t.float
# t.decimal
# t.datetime
# t.timestamp
# t.time
# t.date
# t.binary
# t.boolean
# t.remove
# t.remove_references
# t.remove_belongs_to
# t.remove_index
# t.remove_timestamps
# end
#
class Table
def initialize(table_name, base)
@table_name = table_name
@base = base
end
# Adds a new column to the named table.
# See TableDefinition#column for details of the options you can use.
# ===== Example
# ====== Creating a simple column
# t.column(:name, :string)
def column(column_name, type, options = {})
@base.add_column(@table_name, column_name, type, options)
end
# Adds a new index to the table. +column_name+ can be a single Symbol, or
# an Array of Symbols. See SchemaStatements#add_index
#
# ===== Examples
# ====== Creating a simple index
# t.index(:name)
# ====== Creating a unique index
# t.index([:branch_id, :party_id], :unique => true)
# ====== Creating a named index
# t.index([:branch_id, :party_id], :unique => true, :name => 'by_branch_party')
def index(column_name, options = {})
@base.add_index(@table_name, column_name, options)
end
# Adds timestamps (created_at and updated_at) columns to the table. See SchemaStatements#add_timestamps
# ===== Example
# t.timestamps
def timestamps
@base.add_timestamps(@table_name)
end
# Changes the column's definition according to the new options.
# See TableDefinition#column for details of the options you can use.
# ===== Examples
# t.change(:name, :string, :limit => 80)
# t.change(:description, :text)
def change(column_name, type, options = {})
@base.change_column(@table_name, column_name, type, options)
end
# Sets a new default value for a column. See SchemaStatements#change_column_default
# ===== Examples
# t.change_default(:qualification, 'new')
# t.change_default(:authorized, 1)
def change_default(column_name, default)
@base.change_column_default(@table_name, column_name, default)
end
# Removes the column(s) from the table definition.
# ===== Examples
# t.remove(:qualification)
# t.remove(:qualification, :experience)
def remove(*column_names)
@base.remove_column(@table_name, column_names)
end
# Removes the given index from the table.
#
# ===== Examples
# ====== Remove the suppliers_name_index in the suppliers table
# t.remove_index :name
# ====== Remove the index named accounts_branch_id_index in the accounts table
# t.remove_index :column => :branch_id
# ====== Remove the index named accounts_branch_id_party_id_index in the accounts table
# t.remove_index :column => [:branch_id, :party_id]
# ====== Remove the index named by_branch_party in the accounts table
# t.remove_index :name => :by_branch_party
def remove_index(options = {})
@base.remove_index(@table_name, options)
end
# Removes the timestamp columns (created_at and updated_at) from the table.
# ===== Example
# t.remove_timestamps
def remove_timestamps
@base.remove_timestamps(@table_name)
end
# Renames a column.
# ===== Example
# t.rename(:description, :name)
def rename(column_name, new_column_name)
@base.rename_column(@table_name, column_name, new_column_name)
end
# Adds a reference. Optionally adds a +type+ column.
# <tt>references</tt> and <tt>belongs_to</tt> are acceptable.
# ===== Examples
# t.references(:goat)
# t.references(:goat, :polymorphic => true)
# t.belongs_to(:goat)
def references(*args)
options = args.extract_options!
polymorphic = options.delete(:polymorphic)
args.each do |col|
@base.add_column(@table_name, "#{col}_id", :integer, options)
@base.add_column(@table_name, "#{col}_type", :string, polymorphic.is_a?(Hash) ? polymorphic : options) unless polymorphic.nil?
end
end
alias :belongs_to :references
# Removes a reference. Optionally removes a +type+ column.
# <tt>remove_references</tt> and <tt>remove_belongs_to</tt> are acceptable.
# ===== Examples
# t.remove_references(:goat)
# t.remove_references(:goat, :polymorphic => true)
# t.remove_belongs_to(:goat)
def remove_references(*args)
options = args.extract_options!
polymorphic = options.delete(:polymorphic)
args.each do |col|
@base.remove_column(@table_name, "#{col}_id")
@base.remove_column(@table_name, "#{col}_type") unless polymorphic.nil?
end
end
alias :remove_belongs_to :remove_references
# Adds a column or columns of a specified type
# ===== Examples
# t.string(:goat)
# t.string(:goat, :sheep)
%w( string text integer float decimal datetime timestamp time date binary boolean ).each do |column_type|
class_eval <<-EOV
def #{column_type}(*args) # def string(*args)
options = args.extract_options! # options = args.extract_options!
column_names = args # column_names = args
#
column_names.each do |name| # column_names.each do |name|
column = ColumnDefinition.new(@base, name, '#{column_type}') # column = ColumnDefinition.new(@base, name, 'string')
if options[:limit] # if options[:limit]
column.limit = options[:limit] # column.limit = options[:limit]
elsif native['#{column_type}'.to_sym].is_a?(Hash) # elsif native['string'.to_sym].is_a?(Hash)
column.limit = native['#{column_type}'.to_sym][:limit] # column.limit = native['string'.to_sym][:limit]
end # end
column.precision = options[:precision] # column.precision = options[:precision]
column.scale = options[:scale] # column.scale = options[:scale]
column.default = options[:default] # column.default = options[:default]
column.null = options[:null] # column.null = options[:null]
@base.add_column(@table_name, name, column.sql_type, options) # @base.add_column(@table_name, name, column.sql_type, options)
end # end
end # end
EOV
end
private
def native
@base.native_database_types
end
end
end
end
Jump to Line
Something went wrong with that request. Please try again.