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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, :comment) #: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, :auto_increment, :primary_key, :collation, :sql_type, :comment) #:nodoc:
def primary_key?
primary_key || type.to_sym == :primary_key
end
end
class AddColumnDefinition < Struct.new(:column) # :nodoc:
end
class ChangeColumnDefinition < Struct.new(:column, :name) #:nodoc:
end
class PrimaryKeyDefinition < Struct.new(:name) # :nodoc:
end
class ForeignKeyDefinition < Struct.new(:from_table, :to_table, :options) #:nodoc:
def name
options[:name]
end
def column
options[:column]
end
def primary_key
options[:primary_key] || default_primary_key
end
def on_delete
options[:on_delete]
end
def on_update
options[:on_update]
end
def custom_primary_key?
options[:primary_key] != default_primary_key
end
def defined_for?(to_table_ord = nil, to_table: nil, **options)
if to_table_ord
self.to_table == to_table_ord.to_s
else
(to_table.nil? || to_table.to_s == self.to_table) &&
options.all? { |k, v| self.options[k].to_s == v.to_s }
end
end
private
def default_primary_key
"id"
end
end
class ReferenceDefinition # :nodoc:
def initialize(
name,
polymorphic: false,
index: true,
foreign_key: false,
type: :integer,
**options
)
@name = name
@polymorphic = polymorphic
@index = index
@foreign_key = foreign_key
@type = type
@options = options
if polymorphic && foreign_key
raise ArgumentError, "Cannot add a foreign key to a polymorphic relation"
end
end
def add_to(table)
columns.each do |column_options|
table.column(*column_options)
end
if index
table.index(column_names, index_options)
end
if foreign_key
table.foreign_key(foreign_table_name, foreign_key_options)
end
end
protected
attr_reader :name, :polymorphic, :index, :foreign_key, :type, :options
private
def as_options(value, default = {})
if value.is_a?(Hash)
value
else
default
end
end
def polymorphic_options
as_options(polymorphic, options)
end
def index_options
as_options(index)
end
def foreign_key_options
as_options(foreign_key).merge(column: column_name)
end
def columns
result = [[column_name, type, options]]
if polymorphic
result.unshift(["#{name}_type", :string, polymorphic_options])
end
result
end
def column_name
"#{name}_id"
end
def column_names
columns.map(&:first)
end
def foreign_table_name
foreign_key_options.fetch(:to_table) do
Base.pluralize_table_names ? name.to_s.pluralize : name
end
end
end
module ColumnMethods
# 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
# Appends a column or columns of a specified type.
#
# t.string(:goat)
# t.string(:goat, :sheep)
#
# See TableDefinition#column
[
:bigint,
:binary,
:boolean,
:date,
:datetime,
:decimal,
:float,
:integer,
:string,
:text,
:time,
:timestamp,
].each do |column_type|
module_eval <<-CODE, __FILE__, __LINE__ + 1
def #{column_type}(*args, **options)
args.each { |name| column(name, :#{column_type}, options) }
end
CODE
end
alias_method :numeric, :decimal
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}[rdoc-ref:SchemaStatements#create_table]
# is actually of this type:
#
# class SomeMigration < ActiveRecord::Migration[5.0]
# def up
# create_table :foo do |t|
# puts t.class # => "ActiveRecord::ConnectionAdapters::TableDefinition"
# end
# end
#
# def down
# ...
# end
# end
#
class TableDefinition
include ColumnMethods
attr_accessor :indexes
attr_reader :name, :temporary, :options, :as, :foreign_keys, :comment
def initialize(name, temporary = false, options = nil, as = nil, comment: nil)
@columns_hash = {}
@indexes = []
@foreign_keys = []
@primary_keys = nil
@temporary = temporary
@options = options
@as = as
@name = name
@comment = comment
end
def primary_keys(name = nil) # :nodoc:
@primary_keys = PrimaryKeyDefinition.new(name) if name
@primary_keys
end
# Returns an array of ColumnDefinition objects for the columns of the table.
def columns; @columns_hash.values; 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.
# See {connection.add_column}[rdoc-ref:ConnectionAdapters::SchemaStatements#add_column]
# for available options.
#
# Additional options are:
# * <tt>:index</tt> -
# Create an index for the column. Can be either <tt>true</tt> or an options hash.
#
# This method returns <tt>self</tt>.
#
# == Examples
#
# # Assuming +td+ is an instance of TableDefinition
# td.column(:granted, :boolean, index: true)
#
# == 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 :item_number, :string
# t.column :name, :string, default: "Untitled"
# t.column :value, :string, default: "Untitled"
# t.column :created_at, :datetime
# t.column :updated_at, :datetime
# end
# add_index :products, :item_number
#
# can also be written as follows using the short-hand:
#
# create_table :products do |t|
# t.integer :shop_id, :creator_id
# t.string :item_number, index: true
# t.string :name, :value, default: "Untitled"
# t.timestamps null: false
# 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 {add_index}[rdoc-ref:ConnectionAdapters::SchemaStatements#add_index].
# 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 type
options = options.dup
if @columns_hash[name] && @columns_hash[name].primary_key?
raise ArgumentError, "you can't redefine the primary key column '#{name}'. To define a custom primary key, pass { id: false } to create_table."
end
index_options = options.delete(:index)
index(name, index_options.is_a?(Hash) ? index_options : {}) if index_options
@columns_hash[name] = new_column_definition(name, type, options)
self
end
# remove the column +name+ from the table.
# remove_column(:account_id)
def remove_column(name)
@columns_hash.delete name.to_s
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
def foreign_key(table_name, options = {}) # :nodoc:
table_name_prefix = ActiveRecord::Base.table_name_prefix
table_name_suffix = ActiveRecord::Base.table_name_suffix
table_name = "#{table_name_prefix}#{table_name}#{table_name_suffix}"
foreign_keys.push([table_name, options])
end
# Appends <tt>:datetime</tt> columns <tt>:created_at</tt> and
# <tt>:updated_at</tt> to the table. See {connection.add_timestamps}[rdoc-ref:SchemaStatements#add_timestamps]
#
# t.timestamps null: false
def timestamps(**options)
options[:null] = false if options[:null].nil?
column(:created_at, :datetime, options)
column(:updated_at, :datetime, options)
end
# Adds a reference.
#
# t.references(:user)
# t.belongs_to(:supplier, foreign_key: true)
#
# See {connection.add_reference}[rdoc-ref:SchemaStatements#add_reference] for details of the options you can use.
def references(*args, **options)
args.each do |col|
ReferenceDefinition.new(col, **options).add_to(self)
end
end
alias :belongs_to :references
def new_column_definition(name, type, options) # :nodoc:
type = aliased_types(type.to_s, type)
column = create_column_definition name, type
column.limit = options[: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.auto_increment = options[:auto_increment]
column.primary_key = type == :primary_key || options[:primary_key]
column.collation = options[:collation]
column.comment = options[:comment]
column
end
private
def create_column_definition(name, type)
ColumnDefinition.new name, type
end
def aliased_types(name, fallback)
"timestamp" == name ? :datetime : fallback
end
end
class AlterTable # :nodoc:
attr_reader :adds
attr_reader :foreign_key_adds
attr_reader :foreign_key_drops
def initialize(td)
@td = td
@adds = []
@foreign_key_adds = []
@foreign_key_drops = []
end
def name; @td.name; end
def add_foreign_key(to_table, options)
@foreign_key_adds << ForeignKeyDefinition.new(name, to_table, options)
end
def drop_foreign_key(name)
@foreign_key_drops << name
end
def add_column(name, type, options)
name = name.to_s
type = type.to_sym
@adds << AddColumnDefinition.new(@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 {connection.create_table}[rdoc-ref:SchemaStatements#create_table]
#
# Available transformations are:
#
# change_table :table do |t|
# t.primary_key
# 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.bigint
# t.float
# t.decimal
# t.numeric
# 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
include ColumnMethods
attr_reader :name
def initialize(table_name, base)
@name = table_name
@base = base
end
# Adds a new column to the named table.
#
# t.column(:name, :string)
#
# See TableDefinition#column for details of the options you can use.
def column(column_name, type, options = {})
@base.add_column(name, column_name, type, options)
end
# Checks to see if a column exists.
#
# t.string(:name) unless t.column_exists?(:name, :string)
#
# See {connection.column_exists?}[rdoc-ref:SchemaStatements#column_exists?]
def column_exists?(column_name, type = nil, options = {})
@base.column_exists?(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.
#
# t.index(:name)
# t.index([:branch_id, :party_id], unique: true)
# t.index([:branch_id, :party_id], unique: true, name: 'by_branch_party')
#
# See {connection.add_index}[rdoc-ref:SchemaStatements#add_index] for details of the options you can use.
def index(column_name, options = {})
@base.add_index(name, column_name, options)
end
# Checks to see if an index exists.
#
# unless t.index_exists?(:branch_id)
# t.index(:branch_id)
# end
#
# See {connection.index_exists?}[rdoc-ref:SchemaStatements#index_exists?]
def index_exists?(column_name, options = {})
@base.index_exists?(name, column_name, options)
end
# Renames the given index on the table.
#
# t.rename_index(:user_id, :account_id)
#
# See {connection.rename_index}[rdoc-ref:SchemaStatements#rename_index]
def rename_index(index_name, new_index_name)
@base.rename_index(name, index_name, new_index_name)
end
# Adds timestamps (+created_at+ and +updated_at+) columns to the table.
#
# t.timestamps(null: false)
#
# See {connection.add_timestamps}[rdoc-ref:SchemaStatements#add_timestamps]
def timestamps(options = {})
@base.add_timestamps(name, options)
end
# Changes the column's definition according to the new options.
#
# t.change(:name, :string, limit: 80)
# t.change(:description, :text)
#
# See TableDefinition#column for details of the options you can use.
def change(column_name, type, options = {})
@base.change_column(name, column_name, type, options)
end
# Sets a new default value for a column.
#
# t.change_default(:qualification, 'new')
# t.change_default(:authorized, 1)
# t.change_default(:status, from: nil, to: "draft")
#
# See {connection.change_column_default}[rdoc-ref:SchemaStatements#change_column_default]
def change_default(column_name, default_or_changes)
@base.change_column_default(name, column_name, default_or_changes)
end
# Removes the column(s) from the table definition.
#
# t.remove(:qualification)
# t.remove(:qualification, :experience)
#
# See {connection.remove_columns}[rdoc-ref:SchemaStatements#remove_columns]
def remove(*column_names)
@base.remove_columns(name, *column_names)
end
# Removes the given index from the table.
#
# t.remove_index(:branch_id)
# t.remove_index(column: [:branch_id, :party_id])
# t.remove_index(name: :by_branch_party)
#
# See {connection.remove_index}[rdoc-ref:SchemaStatements#remove_index]
def remove_index(options = {})
@base.remove_index(name, options)
end
# Removes the timestamp columns (+created_at+ and +updated_at+) from the table.
#
# t.remove_timestamps
#
# See {connection.remove_timestamps}[rdoc-ref:SchemaStatements#remove_timestamps]
def remove_timestamps(options = {})
@base.remove_timestamps(name, options)
end
# Renames a column.
#
# t.rename(:description, :name)
#
# See {connection.rename_column}[rdoc-ref:SchemaStatements#rename_column]
def rename(column_name, new_column_name)
@base.rename_column(name, column_name, new_column_name)
end
# Adds a reference.
#
# t.references(:user)
# t.belongs_to(:supplier, foreign_key: true)
#
# See {connection.add_reference}[rdoc-ref:SchemaStatements#add_reference] for details of the options you can use.
def references(*args)
options = args.extract_options!
args.each do |ref_name|
@base.add_reference(name, ref_name, options)
end
end
alias :belongs_to :references
# Removes a reference. Optionally removes a +type+ column.
#
# t.remove_references(:user)
# t.remove_belongs_to(:supplier, polymorphic: true)
#
# See {connection.remove_reference}[rdoc-ref:SchemaStatements#remove_reference]
def remove_references(*args)
options = args.extract_options!
args.each do |ref_name|
@base.remove_reference(name, ref_name, options)
end
end
alias :remove_belongs_to :remove_references
# Adds a foreign key.
#
# t.foreign_key(:authors)
#
# See {connection.add_foreign_key}[rdoc-ref:SchemaStatements#add_foreign_key]
def foreign_key(*args) # :nodoc:
@base.add_foreign_key(name, *args)
end
# Checks to see if a foreign key exists.
#
# t.foreign_key(:authors) unless t.foreign_key_exists?(:authors)
#
# See {connection.foreign_key_exists?}[rdoc-ref:SchemaStatements#foreign_key_exists?]
def foreign_key_exists?(*args) # :nodoc:
@base.foreign_key_exists?(name, *args)
end
end
end
end