require 'active_support/core_ext/object/blank' require 'arel/visitors/bind_visitor' module ActiveRecord module ConnectionAdapters class AbstractMysqlAdapter < AbstractAdapter class Column < ConnectionAdapters::Column # :nodoc: attr_reader :collation def initialize(name, default, sql_type = nil, null = true, collation = nil) super(name, default, sql_type, null) @collation = collation end def extract_default(default) if sql_type =~ /blob/i || type == :text if default.blank? return null ? nil : '' else raise ArgumentError, "#{type} columns cannot have a default value: #{default.inspect}" end elsif missing_default_forged_as_empty_string?(default) nil else super end end def has_default? return false if sql_type =~ /blob/i || type == :text #mysql forbids defaults on blob and text columns super end # Must return the relevant concrete adapter def adapter raise NotImplementedError end def case_sensitive? collation && !collation.match(/_ci$/) end private def simplified_type(field_type) return :boolean if adapter.emulate_booleans && field_type.downcase.index("tinyint(1)") case field_type when /enum/i, /set/i then :string when /year/i then :integer when /bit/i then :binary else super end end def extract_limit(sql_type) case sql_type when /blob|text/i case sql_type when /tiny/i 255 when /medium/i 16777215 when /long/i 2147483647 # mysql only allows 2^31-1, not 2^32-1, somewhat inconsistently with the tiny/medium/normal cases else super # we could return 65535 here, but we leave it undecorated by default end when /^bigint/i; 8 when /^int/i; 4 when /^mediumint/i; 3 when /^smallint/i; 2 when /^tinyint/i; 1 when /^enum\((.+)\)/i $1.split(',').map{|enum| enum.strip.length - 2}.max else super end end # MySQL misreports NOT NULL column default when none is given. # We can't detect this for columns which may have a legitimate '' # default (string) but we can for others (integer, datetime, boolean, # and the rest). # # Test whether the column has default '', is not null, and is not # a type allowing default ''. def missing_default_forged_as_empty_string?(default) type != :string && !null && default == '' end end ## # :singleton-method: # By default, the MysqlAdapter will consider all columns of type tinyint(1) # as boolean. If you wish to disable this emulation (which was the default # behavior in versions 0.13.1 and earlier) you can add the following line # to your application.rb file: # # ActiveRecord::ConnectionAdapters::Mysql[2]Adapter.emulate_booleans = false class_attribute :emulate_booleans self.emulate_booleans = true LOST_CONNECTION_ERROR_MESSAGES = [ "Server shutdown in progress", "Broken pipe", "Lost connection to MySQL server during query", "MySQL server has gone away" ] QUOTED_TRUE, QUOTED_FALSE = '1', '0' NATIVE_DATABASE_TYPES = { :primary_key => "int(11) DEFAULT NULL auto_increment PRIMARY KEY", :string => { :name => "varchar", :limit => 255 }, :text => { :name => "text" }, :integer => { :name => "int", :limit => 4 }, :float => { :name => "float" }, :decimal => { :name => "decimal" }, :datetime => { :name => "datetime" }, :timestamp => { :name => "datetime" }, :time => { :name => "time" }, :date => { :name => "date" }, :binary => { :name => "blob" }, :boolean => { :name => "tinyint", :limit => 1 } } class BindSubstitution < Arel::Visitors::MySQL # :nodoc: include Arel::Visitors::BindVisitor end # FIXME: Make the first parameter more similar for the two adapters def initialize(connection, logger, connection_options, config) super(connection, logger) @connection_options, @config = connection_options, config @quoted_column_names, @quoted_table_names = {}, {} if config.fetch(:prepared_statements) { true } @visitor = Arel::Visitors::MySQL.new self else @visitor = BindSubstitution.new self end end def adapter_name #:nodoc: self.class::ADAPTER_NAME end # Returns true, since this connection adapter supports migrations. def supports_migrations? true end def supports_primary_key? true end # Returns true, since this connection adapter supports savepoints. def supports_savepoints? true end def supports_bulk_alter? #:nodoc: true end # Technically MySQL allows to create indexes with the sort order syntax # but at the moment (5.5) it doesn't yet implement them def supports_index_sort_order? true end def native_database_types NATIVE_DATABASE_TYPES end # HELPER METHODS =========================================== # The two drivers have slightly different ways of yielding hashes of results, so # this method must be implemented to provide a uniform interface. def each_hash(result) # :nodoc: raise NotImplementedError end # Overridden by the adapters to instantiate their specific Column type. def new_column(field, default, type, null, collation) # :nodoc: Column.new(field, default, type, null, collation) end # Must return the Mysql error number from the exception, if the exception has an # error number. def error_number(exception) # :nodoc: raise NotImplementedError end # QUOTING ================================================== def quote(value, column = nil) if value.kind_of?(String) && column && column.type == :binary && column.class.respond_to?(:string_to_binary) s = column.class.string_to_binary(value).unpack("H*")[0] "x'#{s}'" else super end end def quote_column_name(name) #:nodoc: @quoted_column_names[name] ||= "`#{name.to_s.gsub('`', '``')}`" end def quote_table_name(name) #:nodoc: @quoted_table_names[name] ||= quote_column_name(name).gsub('.', '`.`') end def quoted_true QUOTED_TRUE end def quoted_false QUOTED_FALSE end # REFERENTIAL INTEGRITY ==================================== def disable_referential_integrity(&block) #:nodoc: old = select_value("SELECT @@FOREIGN_KEY_CHECKS") begin update("SET FOREIGN_KEY_CHECKS = 0") yield ensure update("SET FOREIGN_KEY_CHECKS = #{old}") end end # DATABASE STATEMENTS ====================================== # Executes the SQL statement in the context of this connection. def execute(sql, name = nil) if name == :skip_logging @connection.query(sql) else log(sql, name) { @connection.query(sql) } end rescue ActiveRecord::StatementInvalid => exception if exception.message.split(":").first =~ /Packets out of order/ raise ActiveRecord::StatementInvalid, "'Packets out of order' error was received from the database. Please update your mysql bindings (gem install mysql) and read http://dev.mysql.com/doc/mysql/en/password-hashing.html for more information. If you're on Windows, use the Instant Rails installer to get the updated mysql bindings." else raise end end # MysqlAdapter has to free a result after using it, so we use this method to write # stuff in a abstract way without concerning ourselves about whether it needs to be # explicitly freed or not. def execute_and_free(sql, name = nil) #:nodoc: yield execute(sql, name) end def update_sql(sql, name = nil) #:nodoc: super @connection.affected_rows end def begin_db_transaction execute "BEGIN" rescue Exception # Transactions aren't supported end def commit_db_transaction #:nodoc: execute "COMMIT" rescue Exception # Transactions aren't supported end def rollback_db_transaction #:nodoc: execute "ROLLBACK" rescue Exception # Transactions aren't supported end def create_savepoint execute("SAVEPOINT #{current_savepoint_name}") end def rollback_to_savepoint execute("ROLLBACK TO SAVEPOINT #{current_savepoint_name}") end def release_savepoint execute("RELEASE SAVEPOINT #{current_savepoint_name}") end # In the simple case, MySQL allows us to place JOINs directly into the UPDATE # query. However, this does not allow for LIMIT, OFFSET and ORDER. To support # these, we must use a subquery. However, MySQL is too stupid to create a # temporary table for this automatically, so we have to give it some prompting # in the form of a subsubquery. Ugh! def join_to_update(update, select) #:nodoc: if select.limit || select.offset || select.orders.any? subsubselect = select.clone subsubselect.projections = [update.key] subselect = Arel::SelectManager.new(select.engine) subselect.project Arel.sql(update.key.name) subselect.from subsubselect.as('__active_record_temp') update.where update.key.in(subselect) else update.table select.source update.wheres = select.constraints end end # SCHEMA STATEMENTS ======================================== def structure_dump #:nodoc: if supports_views? sql = "SHOW FULL TABLES WHERE Table_type = 'BASE TABLE'" else sql = "SHOW TABLES" end select_all(sql).map { |table| table.delete('Table_type') sql = "SHOW CREATE TABLE #{quote_table_name(table.to_a.first.last)}" exec_query(sql).first['Create Table'] + ";\n\n" }.join end # Drops the database specified on the +name+ attribute # and creates it again using the provided +options+. def recreate_database(name, options = {}) drop_database(name) create_database(name, options) end # Create a new MySQL database with optional :charset and :collation. # Charset defaults to utf8. # # Example: # create_database 'charset_test', :charset => 'latin1', :collation => 'latin1_bin' # create_database 'matt_development' # create_database 'matt_development', :charset => :big5 def create_database(name, options = {}) if options[:collation] execute "CREATE DATABASE `#{name}` DEFAULT CHARACTER SET `#{options[:charset] || 'utf8'}` COLLATE `#{options[:collation]}`" else execute "CREATE DATABASE `#{name}` DEFAULT CHARACTER SET `#{options[:charset] || 'utf8'}`" end end # Drops a MySQL database. # # Example: # drop_database('sebastian_development') def drop_database(name) #:nodoc: execute "DROP DATABASE IF EXISTS `#{name}`" end def current_database select_value 'SELECT DATABASE() as db' end # Returns the database character set. def charset show_variable 'character_set_database' end # Returns the database collation strategy. def collation show_variable 'collation_database' end def tables(name = nil, database = nil, like = nil) #:nodoc: sql = "SHOW TABLES " sql << "IN #{quote_table_name(database)} " if database sql << "LIKE #{quote(like)}" if like execute_and_free(sql, 'SCHEMA') do |result| result.collect { |field| field.first } end end def table_exists?(name) return false unless name return true if tables(nil, nil, name).any? name = name.to_s schema, table = name.split('.', 2) unless table # A table was provided without a schema table = schema schema = nil end tables(nil, schema, table).any? end # Returns an array of indexes for the given table. def indexes(table_name, name = nil) #:nodoc: indexes = [] current_index = nil execute_and_free("SHOW KEYS FROM #{quote_table_name(table_name)}", 'SCHEMA') do |result| each_hash(result) do |row| if current_index != row[:Key_name] next if row[:Key_name] == 'PRIMARY' # skip the primary key current_index = row[:Key_name] indexes << IndexDefinition.new(row[:Table], row[:Key_name], row[:Non_unique].to_i == 0, [], []) end indexes.last.columns << row[:Column_name] indexes.last.lengths << row[:Sub_part] end end indexes end # Returns an array of +Column+ objects for the table specified by +table_name+. def columns(table_name, name = nil)#:nodoc: sql = "SHOW FULL FIELDS FROM #{quote_table_name(table_name)}" execute_and_free(sql, 'SCHEMA') do |result| each_hash(result).map do |field| new_column(field[:Field], field[:Default], field[:Type], field[:Null] == "YES", field[:Collation]) end end end def create_table(table_name, options = {}) #:nodoc: super(table_name, options.reverse_merge(:options => "ENGINE=InnoDB")) end def bulk_change_table(table_name, operations) #:nodoc: sqls = operations.map do |command, args| table, arguments = args.shift, args method = :"#{command}_sql" if respond_to?(method, true) send(method, table, *arguments) else raise "Unknown method called : #{method}(#{arguments.inspect})" end end.flatten.join(", ") execute("ALTER TABLE #{quote_table_name(table_name)} #{sqls}") end # Renames a table. # # Example: # rename_table('octopuses', 'octopi') def rename_table(table_name, new_name) execute "RENAME TABLE #{quote_table_name(table_name)} TO #{quote_table_name(new_name)}" end def add_column(table_name, column_name, type, options = {}) execute("ALTER TABLE #{quote_table_name(table_name)} #{add_column_sql(table_name, column_name, type, options)}") end def change_column_default(table_name, column_name, default) column = column_for(table_name, column_name) change_column table_name, column_name, column.sql_type, :default => default end def change_column_null(table_name, column_name, null, default = nil) column = column_for(table_name, column_name) unless null || default.nil? execute("UPDATE #{quote_table_name(table_name)} SET #{quote_column_name(column_name)}=#{quote(default)} WHERE #{quote_column_name(column_name)} IS NULL") end change_column table_name, column_name, column.sql_type, :null => null end def change_column(table_name, column_name, type, options = {}) #:nodoc: execute("ALTER TABLE #{quote_table_name(table_name)} #{change_column_sql(table_name, column_name, type, options)}") end def rename_column(table_name, column_name, new_column_name) #:nodoc: execute("ALTER TABLE #{quote_table_name(table_name)} #{rename_column_sql(table_name, column_name, new_column_name)}") end # Maps logical Rails types to MySQL-specific data types. def type_to_sql(type, limit = nil, precision = nil, scale = nil) case type.to_s when 'integer' case limit when 1; 'tinyint' when 2; 'smallint' when 3; 'mediumint' when nil, 4, 11; 'int(11)' # compatibility with MySQL default when 5..8; 'bigint' else raise(ActiveRecordError, "No integer type has byte size #{limit}") end when 'text' case limit when 0..0xff; 'tinytext' when nil, 0x100..0xffff; 'text' when 0x10000..0xffffff; 'mediumtext' when 0x1000000..0xffffffff; 'longtext' else raise(ActiveRecordError, "No text type has character length #{limit}") end else super end end def add_column_position!(sql, options) if options[:first] sql << " FIRST" elsif options[:after] sql << " AFTER #{quote_column_name(options[:after])}" end end # SHOW VARIABLES LIKE 'name' def show_variable(name) variables = select_all("SHOW VARIABLES LIKE '#{name}'") variables.first['Value'] unless variables.empty? end # Returns a table's primary key and belonging sequence. def pk_and_sequence_for(table) execute_and_free("SHOW CREATE TABLE #{quote_table_name(table)}", 'SCHEMA') do |result| create_table = each_hash(result).first[:"Create Table"] if create_table.to_s =~ /PRIMARY KEY\s+(?:USING\s+\w+\s+)?\((.+)\)/ keys = $1.split(",").map { |key| key.gsub(/[`"]/, "") } keys.length == 1 ? [keys.first, nil] : nil else nil end end end # Returns just a table's primary key def primary_key(table) pk_and_sequence = pk_and_sequence_for(table) pk_and_sequence && pk_and_sequence.first end def case_sensitive_modifier(node) Arel::Nodes::Bin.new(node) end def case_insensitive_comparison(table, attribute, column, value) if column.case_sensitive? super else table[attribute].eq(value) end end def limited_update_conditions(where_sql, quoted_table_name, quoted_primary_key) where_sql end protected def add_index_length(option_strings, column_names, options = {}) if options.is_a?(Hash) && length = options[:length] case length when Hash column_names.each {|name| option_strings[name] += "(#{length[name]})" if length.has_key?(name) && length[name].present?} when Fixnum column_names.each {|name| option_strings[name] += "(#{length})"} end end return option_strings end def quoted_columns_for_index(column_names, options = {}) option_strings = Hash[column_names.map {|name| [name, '']}] # add index length option_strings = add_index_length(option_strings, column_names, options) # add index sort order option_strings = add_index_sort_order(option_strings, column_names, options) column_names.map {|name| quote_column_name(name) + option_strings[name]} end def translate_exception(exception, message) case error_number(exception) when 1062 RecordNotUnique.new(message, exception) when 1452 InvalidForeignKey.new(message, exception) else super end end def add_column_sql(table_name, column_name, type, options = {}) add_column_sql = "ADD #{quote_column_name(column_name)} #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}" add_column_options!(add_column_sql, options) add_column_position!(add_column_sql, options) add_column_sql end def change_column_sql(table_name, column_name, type, options = {}) column = column_for(table_name, column_name) unless options_include_default?(options) options[:default] = column.default end unless options.has_key?(:null) options[:null] = column.null end change_column_sql = "CHANGE #{quote_column_name(column_name)} #{quote_column_name(column_name)} #{type_to_sql(type, options[:limit], options[:precision], options[:scale])}" add_column_options!(change_column_sql, options) add_column_position!(change_column_sql, options) change_column_sql end def rename_column_sql(table_name, column_name, new_column_name) options = {} if column = columns(table_name).find { |c| c.name == column_name.to_s } options[:default] = column.default options[:null] = column.null else raise ActiveRecordError, "No such column: #{table_name}.#{column_name}" end current_type = select_one("SHOW COLUMNS FROM #{quote_table_name(table_name)} LIKE '#{column_name}'")["Type"] rename_column_sql = "CHANGE #{quote_column_name(column_name)} #{quote_column_name(new_column_name)} #{current_type}" add_column_options!(rename_column_sql, options) rename_column_sql end def remove_column_sql(table_name, *column_names) columns_for_remove(table_name, *column_names).map {|column_name| "DROP #{column_name}" } end alias :remove_columns_sql :remove_column def add_index_sql(table_name, column_name, options = {}) index_name, index_type, index_columns = add_index_options(table_name, column_name, options) "ADD #{index_type} INDEX #{index_name} (#{index_columns})" end def remove_index_sql(table_name, options = {}) index_name = index_name_for_remove(table_name, options) "DROP INDEX #{index_name}" end def add_timestamps_sql(table_name) [add_column_sql(table_name, :created_at, :datetime), add_column_sql(table_name, :updated_at, :datetime)] end def remove_timestamps_sql(table_name) [remove_column_sql(table_name, :updated_at), remove_column_sql(table_name, :created_at)] end private def supports_views? version[0] >= 5 end def column_for(table_name, column_name) unless column = columns(table_name).find { |c| c.name == column_name.to_s } raise "No such column: #{table_name}.#{column_name}" end column end end end end