require 'stringio' require 'active_support/core_ext/big_decimal' module ActiveRecord # = Active Record Schema Dumper # # This class is used to dump the database schema for some connection to some # output format (i.e., ActiveRecord::Schema). class SchemaDumper #:nodoc: private_class_method :new ## # :singleton-method: # A list of tables which should not be dumped to the schema. # Acceptable values are strings as well as regexp. # This setting is only used if ActiveRecord::Base.schema_format == :ruby cattr_accessor :ignore_tables @@ignore_tables = [] def self.dump(connection=ActiveRecord::Base.connection, stream=STDOUT) new(connection).dump(stream) stream end def dump(stream) header(stream) extensions(stream) tables(stream) trailer(stream) stream end private def initialize(connection) @connection = connection @types = @connection.native_database_types @version = Migrator::current_version rescue nil end def header(stream) define_params = @version ? "version: #{@version}" : "" if stream.respond_to?(:external_encoding) && stream.external_encoding stream.puts "# encoding: #{stream.external_encoding.name}" end stream.puts <<HEADER # This file is auto-generated from the current state of the database. Instead # of editing this file, please use the migrations feature of Active Record to # incrementally modify your database, and then regenerate this schema definition. # # Note that this schema.rb definition is the authoritative source for your # database schema. If you need to create the application database on another # system, you should be using db:schema:load, not running all the migrations # from scratch. The latter is a flawed and unsustainable approach (the more migrations # you'll amass, the slower it'll run and the greater likelihood for issues). # # It's strongly recommended that you check this file into your version control system. ActiveRecord::Schema.define(#{define_params}) do HEADER end def trailer(stream) stream.puts "end" end def extensions(stream) return unless @connection.supports_extensions? extensions = @connection.extensions if extensions.any? stream.puts " # These are extensions that must be enabled in order to support this database" extensions.each do |extension| stream.puts " enable_extension #{extension.inspect}" end stream.puts end end def tables(stream) @connection.tables.sort.each do |tbl| next if ['schema_migrations', ignore_tables].flatten.any? do |ignored| case ignored when String; remove_prefix_and_suffix(tbl) == ignored when Regexp; remove_prefix_and_suffix(tbl) =~ ignored else raise StandardError, 'ActiveRecord::SchemaDumper.ignore_tables accepts an array of String and / or Regexp values.' end end table(tbl, stream) end end def table(table, stream) columns = @connection.columns(table) begin tbl = StringIO.new # first dump primary key column if @connection.respond_to?(:pk_and_sequence_for) pk, _ = @connection.pk_and_sequence_for(table) elsif @connection.respond_to?(:primary_key) pk = @connection.primary_key(table) end tbl.print " create_table #{remove_prefix_and_suffix(table).inspect}" if columns.detect { |c| c.name == pk } if pk != 'id' tbl.print %Q(, primary_key: "#{pk}") end else tbl.print ", id: false" end tbl.print ", force: true" tbl.puts " do |t|" # then dump all non-primary key columns column_specs = columns.map do |column| raise StandardError, "Unknown type '#{column.sql_type}' for column '#{column.name}'" unless @connection.valid_type?(column.type) next if column.name == pk @connection.column_spec(column, @types) end.compact # find all migration keys used in this table keys = @connection.migration_keys # figure out the lengths for each column based on above keys lengths = keys.map { |key| column_specs.map { |spec| spec[key] ? spec[key].length + 2 : 0 }.max } # the string we're going to sprintf our values against, with standardized column widths format_string = lengths.map{ |len| "%-#{len}s" } # find the max length for the 'type' column, which is special type_length = column_specs.map{ |column| column[:type].length }.max # add column type definition to our format string format_string.unshift " t.%-#{type_length}s " format_string *= '' column_specs.each do |colspec| values = keys.zip(lengths).map{ |key, len| colspec.key?(key) ? colspec[key] + ", " : " " * len } values.unshift colspec[:type] tbl.print((format_string % values).gsub(/,\s*$/, '')) tbl.puts end tbl.puts " end" tbl.puts indexes(table, tbl) tbl.rewind stream.print tbl.read rescue => e stream.puts "# Could not dump table #{table.inspect} because of following #{e.class}" stream.puts "# #{e.message}" stream.puts end stream end def indexes(table, stream) if (indexes = @connection.indexes(table)).any? add_index_statements = indexes.map do |index| statement_parts = [ ('add_index ' + remove_prefix_and_suffix(index.table).inspect), index.columns.inspect, ('name: ' + index.name.inspect), ] statement_parts << 'unique: true' if index.unique index_lengths = (index.lengths || []).compact statement_parts << ('length: ' + Hash[index.columns.zip(index.lengths)].inspect) unless index_lengths.empty? index_orders = (index.orders || {}) statement_parts << ('order: ' + index.orders.inspect) unless index_orders.empty? statement_parts << ('where: ' + index.where.inspect) if index.where statement_parts << ('using: ' + index.using.inspect) if index.using statement_parts << ('type: ' + index.type.inspect) if index.type ' ' + statement_parts.join(', ') end stream.puts add_index_statements.sort.join("\n") stream.puts end end def remove_prefix_and_suffix(table) table.gsub(/^(#{ActiveRecord::Base.table_name_prefix})(.+)(#{ActiveRecord::Base.table_name_suffix})$/, "\\2") end end end