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: # :primary_key, :string, :text, # :integer, :float, :decimal, # :datetime, :timestamp, :time, # :date, :binary, :boolean. # # 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): # * :limit - # Requests a maximum column length. This is number of characters for :string and # :text columns and number of bytes for :binary and :integer columns. # * :default - # The column's default value. Use nil for NULL. # * :null - # Allows or disallows +NULL+ values in the column. This option could # have been named :null_allowed. # * :precision - # Specifies the precision for a :decimal column. # * :scale - # Specifies the scale for a :decimal 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 # :decimal columns: # * The SQL standard says the default scale should be 0, :scale <= # :precision, and makes no comments about the requirements of # :precision. # * MySQL: :precision [1..63], :scale [0..30]. # Default is (10,0). # * PostgreSQL: :precision [1..infinity], # :scale [0..infinity]. No default. # * SQLite2: Any :precision and :scale may be used. # Internal storage as strings. No default. # * SQLite3: No restrictions on :precision and :scale, # but the maximum supported :precision is 16. No default. # * Oracle: :precision [1..38], :scale [-84..127]. # Default is (38,0). # * DB2: :precision [1..63], :scale [0..62]. # Default unknown. # * Firebird: :precision [1..18], :scale [0..18]. # Default (9,0). Internal types NUMERIC and DECIMAL have different # storage rules, decimal being better. # * FrontBase?: :precision [1..38], :scale [0..38]. # Default (38,0). WARNING Max :precision/:scale for # NUMERIC is 19, and DECIMAL is 38. # * SqlServer?: :precision [1..38], :scale [0..38]. # Default (38,0). # * Sybase: :precision [1..38], :scale [0..38]. # Default (38,0). # * OpenBase?: Documentation unclear. Claims storage in double. # # This method returns self. # # == 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 :scale 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 :polymorphic option is supplied. If :polymorphic is a hash of # options, these will be used when creating the _type column. The :index option # will also create an index, similar to calling 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 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 :datetime columns :created_at and # :updated_at 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.array = options[:array] if column.respond_to?(:array) 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 :polymorphic option is provided. # references and belongs_to 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. # remove_references and remove_belongs_to 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