require "stringio" 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 if ActiveRecord::Base.schema_format == :ruby. # Only strings are accepted if ActiveRecord::Base.schema_format == :sql. cattr_accessor :ignore_tables, default: [] class << self def dump(connection = ActiveRecord::Base.connection, stream = STDOUT, config = ActiveRecord::Base) new(connection, generate_options(config)).dump(stream) stream end private def generate_options(config) { table_name_prefix: config.table_name_prefix, table_name_suffix: config.table_name_suffix } end end def dump(stream) header(stream) extensions(stream) tables(stream) trailer(stream) stream end private def initialize(connection, options = {}) @connection = connection @version = Migrator::current_version rescue nil @options = options end # turns 20170404131909 into "2017_04_04_131909" def formatted_version stringified = @version.to_s return stringified unless stringified.length == 14 stringified.insert(4, "_").insert(7, "_").insert(10, "_") end def define_params @version ? "version: #{formatted_version}" : "" end def header(stream) 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) sorted_tables = @connection.tables.sort sorted_tables.each do |table_name| table(table_name, stream) unless ignored?(table_name) end # dump foreign keys at the end to make sure all dependent tables exist. if @connection.supports_foreign_keys? sorted_tables.each do |tbl| foreign_keys(tbl, stream) unless ignored?(tbl) end end end def table(table, stream) columns = @connection.columns(table) begin tbl = StringIO.new # first dump primary key column pk = @connection.primary_key(table) tbl.print " create_table #{remove_prefix_and_suffix(table).inspect}" case pk when String tbl.print ", primary_key: #{pk.inspect}" unless pk == "id" pkcol = columns.detect { |c| c.name == pk } pkcolspec = @connection.column_spec_for_primary_key(pkcol) if pkcolspec.present? tbl.print ", #{format_colspec(pkcolspec)}" end when Array tbl.print ", primary_key: #{pk.inspect}" else tbl.print ", id: false" end tbl.print ", force: :cascade" table_options = @connection.table_options(table) if table_options.present? tbl.print ", #{format_options(table_options)}" end tbl.puts " do |t|" # then dump all non-primary key columns columns.each do |column| raise StandardError, "Unknown type '#{column.sql_type}' for column '#{column.name}'" unless @connection.valid_type?(column.type) next if column.name == pk type, colspec = @connection.column_spec(column) tbl.print " t.#{type} #{column.name.inspect}" tbl.print ", #{format_colspec(colspec)}" if colspec.present? tbl.puts end indexes_in_create(table, tbl) tbl.puts " end" tbl.puts 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 # Keep it for indexing materialized views def indexes(table, stream) if (indexes = @connection.indexes(table)).any? add_index_statements = indexes.map do |index| table_name = remove_prefix_and_suffix(index.table).inspect " add_index #{([table_name] + index_parts(index)).join(', ')}" end stream.puts add_index_statements.sort.join("\n") stream.puts end end def indexes_in_create(table, stream) if (indexes = @connection.indexes(table)).any? index_statements = indexes.map do |index| " t.index #{index_parts(index).join(', ')}" end stream.puts index_statements.sort.join("\n") end end def index_parts(index) index_parts = [ index.columns.inspect, "name: #{index.name.inspect}", ] index_parts << "unique: true" if index.unique index_parts << "length: { #{format_options(index.lengths)} }" if index.lengths.present? index_parts << "order: { #{format_options(index.orders)} }" if index.orders.present? index_parts << "where: #{index.where.inspect}" if index.where index_parts << "using: #{index.using.inspect}" if !@connection.default_index_type?(index) index_parts << "type: #{index.type.inspect}" if index.type index_parts << "comment: #{index.comment.inspect}" if index.comment index_parts end def foreign_keys(table, stream) if (foreign_keys = @connection.foreign_keys(table)).any? add_foreign_key_statements = foreign_keys.map do |foreign_key| parts = [ "add_foreign_key #{remove_prefix_and_suffix(foreign_key.from_table).inspect}", remove_prefix_and_suffix(foreign_key.to_table).inspect, ] if foreign_key.column != @connection.foreign_key_column_for(foreign_key.to_table) parts << "column: #{foreign_key.column.inspect}" end if foreign_key.custom_primary_key? parts << "primary_key: #{foreign_key.primary_key.inspect}" end if foreign_key.name !~ /^fk_rails_[0-9a-f]{10}$/ parts << "name: #{foreign_key.name.inspect}" end parts << "on_update: #{foreign_key.on_update.inspect}" if foreign_key.on_update parts << "on_delete: #{foreign_key.on_delete.inspect}" if foreign_key.on_delete " #{parts.join(', ')}" end stream.puts add_foreign_key_statements.sort.join("\n") end end def format_colspec(colspec) colspec.map { |key, value| "#{key}: #{value}" }.join(", ") end def format_options(options) options.map { |key, value| "#{key}: #{value.inspect}" }.join(", ") end def remove_prefix_and_suffix(table) table.gsub(/^(#{@options[:table_name_prefix]})(.+)(#{@options[:table_name_suffix]})$/, "\\2") end def ignored?(table_name) [ActiveRecord::Base.schema_migrations_table_name, ActiveRecord::Base.internal_metadata_table_name, ignore_tables].flatten.any? do |ignored| ignored === remove_prefix_and_suffix(table_name) end end end end