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require 'date'
require 'set'
require 'bigdecimal'
require 'bigdecimal/util'
module ActiveRecord
module ConnectionAdapters #:nodoc:
# Abstract representation of an index definition on a table. Instances of
# this type are typically created and returned by methods in database
# adapters. e.g. ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter#indexes
class IndexDefinition < Struct.new(:table, :name, :unique, :columns, :lengths, :orders, :where, :type, :using) #: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(:name, :type, :limit, :precision, :scale, :default, :null, :first, :after, :primary_key) #:nodoc:
def string_to_binary(value)
value
end
def primary_key?
primary_key || type.to_sym == :primary_key
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+
# is actually of this type:
#
# class SomeMigration < ActiveRecord::Migration
# def up
# create_table :foo do |t|
# puts t.class # => "ActiveRecord::ConnectionAdapters::TableDefinition"
# end
# end
#
# def 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 :indexes
attr_reader :name, :temporary, :options
def initialize(types, name, temporary, options)
@columns_hash = {}
@indexes = {}
@native = types
@temporary = temporary
@options = options
@name = name
end
def columns; @columns_hash.values; 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, type = :primary_key, options = {})
column(name, type, options.merge(:primary_key => true))
end
# Returns a ColumnDefinition for the column with name +name+.
def [](name)
@columns_hash[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 <tt>:binary</tt> and <tt>:integer</tt> 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 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. The <tt>:index</tt> option
# will also create an index, similar to calling <tt>add_index</tt>. 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
# add_index :taggings, :tag_id, name: 'index_taggings_on_tag_id'
# add_index :taggings, [:tagger_id, :tagger_type]
#
# Can also be written as follows using references:
#
# create_table :taggings do |t|
# t.references :tag, index: { name: 'index_taggings_on_tag_id' }
# t.references :tagger, polymorphic: true, index: true
# t.references :taggable, polymorphic: { default: 'Photo' }
# end
def column(name, type, options = {})
name = name.to_s
type = type.to_sym
if primary_key_column_name == name
raise ArgumentError, "you can't redefine the primary key column '#{name}'. To define a custom primary key, pass { id: false } to create_table."
end
@columns_hash[name] = new_column_definition(name, type, options)
self
end
def remove_column(name)
@columns_hash.delete name.to_s
end
[:string, :text, :integer, :float, :decimal, :datetime, :timestamp, :time, :date, :binary, :boolean].each do |column_type|
define_method column_type do |*args|
options = args.extract_options!
column_names = args
column_names.each { |name| column(name, column_type, options) }
end
end
# Adds index options to the indexes hash, keyed by column name
# This is primarily used to track indexes that need to be created after the table
#
# index(:account_id, name: 'index_projects_on_account_id')
def index(column_name, options = {})
indexes[column_name] = options
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)
index_options = options.delete(:index)
args.each do |col|
column("#{col}_id", :integer, options)
column("#{col}_type", :string, polymorphic.is_a?(Hash) ? polymorphic : options) if polymorphic
index(polymorphic ? %w(id type).map { |t| "#{col}_#{t}" } : "#{col}_id", index_options.is_a?(Hash) ? index_options : {}) if index_options
end
end
alias :belongs_to :references
def new_column_definition(name, type, options) # :nodoc:
column = create_column_definition name, type
limit = options.fetch(:limit) do
native[type][:limit] if native[type].is_a?(Hash)
end
column.limit = limit
column.precision = options[:precision]
column.scale = options[:scale]
column.default = options[:default]
column.null = options[:null]
column.first = options[:first]
column.after = options[:after]
column.primary_key = type == :primary_key || options[:primary_key]
column
end
private
def create_column_definition(name, type)
ColumnDefinition.new name, type
end
def primary_key_column_name
primary_key_column = columns.detect { |c| c.primary_key? }
primary_key_column && primary_key_column.name
end
def native
@native
end
end
class AlterTable # :nodoc:
attr_reader :adds
def initialize(td)
@td = td
@adds = []
end
def name; @td.name; end
def add_column(name, type, options)
name = name.to_s
type = type.to_sym
@adds << @td.new_column_definition(name, type, options)
end
end
# Represents an 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.rename_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.
#
# ====== Creating a simple column
# t.column(:name, :string)
def column(column_name, type, options = {})
@base.add_column(@table_name, column_name, type, options)
end
# Checks to see if a column exists. See SchemaStatements#column_exists?
def column_exists?(column_name, type = nil, options = {})
@base.column_exists?(@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
#
# ====== 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
# Checks to see if an index exists. See SchemaStatements#index_exists?
def index_exists?(column_name, options = {})
@base.index_exists?(@table_name, column_name, options)
end
# Renames the given index on the table.
#
# t.rename_index(:user_id, :account_id)
def rename_index(index_name, new_index_name)
@base.rename_index(@table_name, index_name, new_index_name)
end
# Adds timestamps (+created_at+ and +updated_at+) columns to the table. See SchemaStatements#add_timestamps
#
# 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.
#
# 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
#
# 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.
#
# t.remove(:qualification)
# t.remove(:qualification, :experience)
def remove(*column_names)
@base.remove_columns(@table_name, *column_names)
end
# Removes the given index from the table.
#
# ====== Remove the index_table_name_on_column in the table_name table
# t.remove_index :column
# ====== Remove the index named index_table_name_on_branch_id in the table_name table
# t.remove_index column: :branch_id
# ====== Remove the index named index_table_name_on_branch_id_and_party_id in the table_name table
# t.remove_index column: [:branch_id, :party_id]
# ====== Remove the index named by_branch_party in the table_name 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.
#
# t.remove_timestamps
def remove_timestamps
@base.remove_timestamps(@table_name)
end
# Renames a column.
#
# 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, if <tt>:polymorphic</tt> option is provided.
# <tt>references</tt> and <tt>belongs_to</tt> are acceptable.
#
# t.references(:user)
# t.belongs_to(:supplier, polymorphic: true)
#
def references(*args)
options = args.extract_options!
args.each do |ref_name|
@base.add_reference(@table_name, ref_name, options)
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.
#
# t.remove_references(:user)
# t.remove_belongs_to(:supplier, polymorphic: true)
#
def remove_references(*args)
options = args.extract_options!
args.each do |ref_name|
@base.remove_reference(@table_name, ref_name, options)
end
end
alias :remove_belongs_to :remove_references
# Adds a column or columns of a specified type
#
# t.string(:goat)
# t.string(:goat, :sheep)
[:string, :text, :integer, :float, :decimal, :datetime, :timestamp, :time, :date, :binary, :boolean].each do |column_type|
define_method column_type do |*args|
options = args.extract_options!
args.each do |name|
@base.add_column(@table_name, name, column_type, options)
end
end
end
private
def native
@base.native_database_types
end
end
end
end
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