require 'stringio' require 'active_support/core_ext/big_decimal' module ActiveRecord # 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) 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}" : "" stream.puts <
"#{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}'" if @types[column.type].nil? next if column.name == pk spec = {} spec[:name] = column.name.inspect # AR has an optimisation which handles zero-scale decimals as integers. This # code ensures that the dumper still dumps the column as a decimal. spec[:type] = if column.type == :integer && [/^numeric/, /^decimal/].any? { |e| e.match(column.sql_type) } 'decimal' else column.type.to_s end spec[:limit] = column.limit.inspect if column.limit != @types[column.type][:limit] && spec[:type] != 'decimal' spec[:precision] = column.precision.inspect if !column.precision.nil? spec[:scale] = column.scale.inspect if !column.scale.nil? spec[:null] = 'false' if !column.null spec[:default] = default_string(column.default) if column.has_default? (spec.keys - [:name, :type]).each{ |k| spec[k].insert(0, "#{k.inspect} => ")} spec end.compact # find all migration keys used in this table keys = [:name, :limit, :precision, :scale, :default, :null] & column_specs.map(&:keys).flatten # 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 default_string(value) case value when BigDecimal value.to_s when Date, DateTime, Time "'" + value.to_s(:db) + "'" else value.inspect end end def indexes(table, stream) if (indexes = @connection.indexes(table)).any? add_index_statements = indexes.map do |index| statement_parts = [ ('add_index ' + index.table.inspect) ] statement_parts << index.columns.inspect statement_parts << (':name => ' + index.name.inspect) statement_parts << ':unique => true' if index.unique index_lengths = index.lengths.compact if index.lengths.is_a?(Array) statement_parts << (':length => ' + Hash[*index.columns.zip(index.lengths).flatten].inspect) if index_lengths.present? ' ' + statement_parts.join(', ') end stream.puts add_index_statements.sort.join("\n") stream.puts end end end end