module Sequel::SequelMethods

Sequel doesn't pay much attention to timezones by default, but you can set it to handle timezones if you want. There are three separate timezone settings:

All three timezones have getter and setter methods. You can set all three timezones to the same value at once via Sequel.default_timezone=.

The only timezone values that are supported by default are :utc (convert to UTC), :local (convert to local time), and nil (don't convert). If you need to convert to a specific timezone, or need the timezones being used to change based on the environment (e.g. current user), you need to use the named_timezones extension (and use DateTime as the datetime_class). Sequel also ships with a thread_local_timezones extensions which allows each thread to have its own timezone values for each of the timezones.

Attributes

application_timezone[R]

The timezone you want the application to use. This is the timezone that incoming times from the database and typecasting are converted to.

convert_two_digit_years[RW]

Sequel converts two digit years in Dates and DateTimes by default, so 01/02/03 is interpreted at January 2nd, 2003, and 12/13/99 is interpreted as December 13, 1999. You can override this to treat those dates as January 2nd, 0003 and December 13, 0099, respectively, by:

Sequel.convert_two_digit_years = false
database_timezone[R]

The timezone for storage in the database. This is the timezone to which Sequel will convert timestamps before literalizing them for storage in the database. It is also the timezone that Sequel will assume database timestamp values are already in (if they don't include an offset).

datetime_class[RW]

Sequel can use either Time or DateTime for times returned from the database. It defaults to Time. To change it to DateTime:

Sequel.datetime_class = DateTime

Note that Time and DateTime objects have a different API, and in cases where they implement the same methods, they often implement them differently (e.g. + using seconds on Time and days on DateTime).

single_threaded[RW]

Set whether Sequel is being used in single threaded mode. By default, Sequel uses a thread-safe connection pool, which isn't as fast as the single threaded connection pool, and also has some additional thread safety checks. If your program will only have one thread, and speed is a priority, you should set this to true:

Sequel.single_threaded = true
typecast_timezone[R]

The timezone that incoming data that Sequel needs to typecast is assumed to be already in (if they don't include an offset).

Public Instance Methods

application_to_database_timestamp(v) click to toggle source

Convert the given Time/DateTime object into the database timezone, used when literalizing objects in an SQL string.

# File lib/sequel/timezones.rb, line 49
def application_to_database_timestamp(v)
  convert_output_timestamp(v, Sequel.database_timezone)
end
condition_specifier?(obj) click to toggle source

Returns true if the passed object could be a specifier of conditions, false otherwise. Currently, Sequel considers hashes and arrays of two element arrays as condition specifiers.

Sequel.condition_specifier?({}) # => true
Sequel.condition_specifier?([[1, 2]]) # => true
Sequel.condition_specifier?([]) # => false
Sequel.condition_specifier?([1]) # => false
Sequel.condition_specifier?(1) # => false
# File lib/sequel/core.rb, line 82
def condition_specifier?(obj)
  case obj
  when Hash
    true
  when Array
    !obj.empty? && !obj.is_a?(SQL::ValueList) && obj.all?{|i| i.is_a?(Array) && (i.length == 2)}
  else
    false
  end
end
connect(*args, &block) click to toggle source

Creates a new database object based on the supplied connection string and optional arguments. The specified scheme determines the database class used, and the rest of the string specifies the connection options. For example:

DB = Sequel.connect('sqlite:/') # Memory database
DB = Sequel.connect('sqlite://blog.db') # ./blog.db
DB = Sequel.connect('sqlite:///blog.db') # /blog.db
DB = Sequel.connect('postgres://user:password@host:port/database_name')
DB = Sequel.connect('sqlite:///blog.db', max_connections: 10)

You can also pass a single options hash:

DB = Sequel.connect(adapter: 'sqlite', database: './blog.db')

If a block is given, it is passed the opened Database object, which is closed when the block exits. For example:

Sequel.connect('sqlite://blog.db'){|db| puts db[:users].count}

If a block is not given, a reference to this database will be held in Sequel::DATABASES until it is removed manually. This is by design, and used by Sequel::Model to pick the default database. It is recommended to pass a block if you do not want the resulting Database object to remain in memory until the process terminates, or use the keep_reference: false Database option.

For details, see the “Connecting to a Database” guide. To set up a primary/replica or sharded database connection, see the “Primary/Replica Database Configurations and Sharding” guide.

# File lib/sequel/core.rb, line 122
def connect(*args, &block)
  Database.connect(*args, &block)
end
convert_exception_class(exception, klass) click to toggle source

Convert the exception to the given class. The given class should be Sequel::Error or a subclass. Returns an instance of klass with the message and backtrace of exception.

# File lib/sequel/core.rb, line 135
def convert_exception_class(exception, klass)
  return exception if exception.is_a?(klass)
  e = klass.new("#{exception.class}: #{exception.message}")
  e.wrapped_exception = exception
  e.set_backtrace(exception.backtrace)
  e
end
convert_output_timestamp(v, output_timezone) click to toggle source

Converts the object to the given output_timezone.

# File lib/sequel/timezones.rb, line 54
def convert_output_timestamp(v, output_timezone)
  if output_timezone
    if v.is_a?(DateTime)
      case output_timezone
      when :utc
        v.new_offset(0)
      when :local
        v.new_offset(local_offset_for_datetime(v))
      else
        convert_output_datetime_other(v, output_timezone)
      end
    else
      case output_timezone
      when :utc
        v.getutc
      when :local
        v.getlocal
      else
        convert_output_time_other(v, output_timezone)
      end
    end
  else
    v
  end
end
convert_timestamp(v, input_timezone) click to toggle source

Converts the given object from the given input timezone to the application_timezone using convert_input_timestamp and convert_output_timestamp.

# File lib/sequel/timezones.rb, line 83
def convert_timestamp(v, input_timezone)
  if v.is_a?(Date) && !v.is_a?(DateTime)
    # Dates handled specially as they are assumed to already be in the application_timezone
    if datetime_class == DateTime
      DateTime.civil(v.year, v.month, v.day, 0, 0, 0, application_timezone == :local ? Rational(Time.local(v.year, v.month, v.day).utc_offset, 86400) : 0)
    else
      Time.public_send(application_timezone == :utc ? :utc : :local, v.year, v.month, v.day)
    end
  else
    convert_output_timestamp(convert_input_timestamp(v, input_timezone), application_timezone)
  end
rescue InvalidValue
  raise
rescue => e
  raise convert_exception_class(e, InvalidValue)
end
core_extensions?() click to toggle source

Assume the core extensions are not loaded by default, if the core_extensions extension is loaded, this will be overridden.

# File lib/sequel/core.rb, line 128
def core_extensions?
  false
end
current() click to toggle source

The current concurrency primitive, Thread.current by default.

# File lib/sequel/core.rb, line 144
def current
  Thread.current
end
database_to_application_timestamp(v) click to toggle source

Convert the given object into an object of Sequel.datetime_class in the application_timezone. Used when converting datetime/timestamp columns returned by the database.

# File lib/sequel/timezones.rb, line 103
def database_to_application_timestamp(v)
  convert_timestamp(v, Sequel.database_timezone)
end
default_timezone=(tz) click to toggle source

Sets the database, application, and typecasting timezones to the given timezone.

# File lib/sequel/timezones.rb, line 108
def default_timezone=(tz)
  self.database_timezone = tz
  self.application_timezone = tz
  self.typecast_timezone = tz
end
elapsed_seconds_since(timer) click to toggle source

The elapsed seconds since the given timer object was created. The timer object should have been created via Sequel.start_timer.

# File lib/sequel/core.rb, line 334
def elapsed_seconds_since(timer)
  start_timer - timer
end
extension(*extensions) click to toggle source

Load all Sequel extensions given. Extensions are just files that exist under sequel/extensions in the load path, and are just required.

In some cases, requiring an extension modifies classes directly, and in others, it just loads a module that you can extend other classes with. Consult the documentation for each extension you plan on using for usage.

Sequel.extension(:blank)
Sequel.extension(:core_extensions, :named_timezones)
# File lib/sequel/core.rb, line 156
def extension(*extensions)
  extensions.each{|e| orig_require("sequel/extensions/#{e}")}
end
json_parser_error_class() click to toggle source

The exception classed raised if there is an error parsing JSON. This can be overridden to use an alternative json implementation.

# File lib/sequel/core.rb, line 162
def json_parser_error_class
  JSON::ParserError
end
object_to_json(obj, *args, &block) click to toggle source

Convert given object to json and return the result. This can be overridden to use an alternative json implementation.

# File lib/sequel/core.rb, line 168
def object_to_json(obj, *args, &block)
  obj.to_json(*args, &block)
end
orig_require(files, subdir=nil)

Alias of original require method, as Sequel.require does a relative require for backwards compatibility.

Alias for: require
parse_json(json) click to toggle source

Parse the string as JSON and return the result. This can be overridden to use an alternative json implementation.

# File lib/sequel/core.rb, line 174
def parse_json(json)
  JSON.parse(json, :create_additions=>false)
end
recursive_map(array, converter) click to toggle source

Convert each item in the array to the correct type, handling multi-dimensional arrays. For each element in the array or subarrays, call the converter, unless the value is nil.

# File lib/sequel/core.rb, line 192
def recursive_map(array, converter)
  array.map do |i|
    if i.is_a?(Array)
      recursive_map(i, converter)
    elsif !i.nil?
      converter.call(i)
    end
  end
end
require(files, subdir=nil) click to toggle source

For backwards compatibility only. require_relative should be used instead.

# File lib/sequel/core.rb, line 203
def require(files, subdir=nil)
  # Use Kernel.require_relative to work around JRuby 9.0 bug
  Array(files).each{|f| Kernel.require_relative "#{"#{subdir}/" if subdir}#{f}"}
end
Also aliased as: orig_require
split_symbol(sym) click to toggle source

Splits the symbol into three parts, if symbol splitting is enabled (not the default). Each part will either be a string or nil. If symbol splitting is disabled, returns an array with the first and third parts being nil, and the second part beind a string version of the symbol.

For columns, these parts are the table, column, and alias. For tables, these parts are the schema, table, and alias.

# File lib/sequel/core.rb, line 215
def split_symbol(sym)
  unless v = Sequel.synchronize{SPLIT_SYMBOL_CACHE[sym]}
    if split_symbols?
      v = case s = sym.to_s
      when /\A((?:(?!__).)+)__((?:(?!___).)+)___(.+)\z/
        [$1.freeze, $2.freeze, $3.freeze].freeze
      when /\A((?:(?!___).)+)___(.+)\z/
        [nil, $1.freeze, $2.freeze].freeze
      when /\A((?:(?!__).)+)__(.+)\z/
        [$1.freeze, $2.freeze, nil].freeze
      else
        [nil, s.freeze, nil].freeze
      end
    else
      v = [nil,sym.to_s.freeze,nil].freeze
    end
    Sequel.synchronize{SPLIT_SYMBOL_CACHE[sym] = v}
  end
  v
end
split_symbols=(v) click to toggle source

Setting this to true enables Sequel's historical behavior of splitting symbols on double or triple underscores:

:table__column         # table.column
:column___alias        # column AS alias
:table__column___alias # table.column AS alias

It is only recommended to turn this on for backwards compatibility until such symbols have been converted to use newer Sequel APIs such as:

Sequel[:table][:column]            # table.column
Sequel[:column].as(:alias)         # column AS alias
Sequel[:table][:column].as(:alias) # table.column AS alias

Sequel::Database instances do their own caching of literalized symbols, and changing this setting does not affect those caches. It is recommended that if you want to change this setting, you do so directly after requiring Sequel, before creating any Sequel::Database instances.

Disabling symbol splitting will also disable the handling of double underscores in virtual row methods, causing such methods to yield regular identifers instead of qualified identifiers:

# Sequel.split_symbols = true
Sequel.expr{table__column}  # table.column
Sequel.expr{table[:column]} # table.column

# Sequel.split_symbols = false
Sequel.expr{table__column}  # table__column
Sequel.expr{table[:column]} # table.column
# File lib/sequel/core.rb, line 266
def split_symbols=(v)
  Sequel.synchronize{SPLIT_SYMBOL_CACHE.clear}
  @split_symbols = v
end
split_symbols?() click to toggle source

Whether Sequel currently splits symbols into qualified/aliased identifiers.

# File lib/sequel/core.rb, line 272
def split_symbols?
  @split_symbols
end
start_timer() click to toggle source

A timer object that can be passed to Sequel.elapsed_seconds_since to return the number of seconds elapsed.

# File lib/sequel/core.rb, line 321
def start_timer
  Process.clock_gettime(Process::CLOCK_MONOTONIC)
end
string_to_date(string) click to toggle source

Converts the given string into a Date object.

Sequel.string_to_date('2010-09-10') # Date.civil(2010, 09, 10)
# File lib/sequel/core.rb, line 279
def string_to_date(string)
  Date.parse(string, Sequel.convert_two_digit_years)
rescue => e
  raise convert_exception_class(e, InvalidValue)
end
string_to_datetime(string) click to toggle source

Converts the given string into a Time or DateTime object, depending on the value of Sequel.datetime_class.

Sequel.string_to_datetime('2010-09-10 10:20:30') # Time.local(2010, 09, 10, 10, 20, 30)
# File lib/sequel/core.rb, line 289
def string_to_datetime(string)
  if datetime_class == DateTime
    DateTime.parse(string, convert_two_digit_years)
  else
    datetime_class.parse(string)
  end
rescue => e
  raise convert_exception_class(e, InvalidValue)
end
string_to_time(string) click to toggle source

Converts the given string into a Sequel::SQLTime object.

v = Sequel.string_to_time('10:20:30') # Sequel::SQLTime.parse('10:20:30')
DB.literal(v) # => '10:20:30'
# File lib/sequel/core.rb, line 303
def string_to_time(string)
  SQLTime.parse(string)
rescue => e
  raise convert_exception_class(e, InvalidValue)
end
synchronize() { |: synchronize(&block)| ... } click to toggle source

Unless in single threaded mode, protects access to any mutable global data structure in Sequel. Uses a non-reentrant mutex, so calling code should be careful. In general, this should only be used around the minimal possible code such as Hash#[], Hash#[]=, Hash#delete, Array#<<, and Array#delete.

# File lib/sequel/core.rb, line 314
def synchronize(&block)
  @single_threaded ? yield : @data_mutex.synchronize(&block)
end
synchronize_with(mutex) { || ... } click to toggle source

If a mutex is given, synchronize access using it. If nil is given, just yield to the block. This is designed for cases where a mutex may or may not be provided.

# File lib/sequel/core.rb, line 181
def synchronize_with(mutex)
  if mutex
    mutex.synchronize{yield}
  else
    yield
  end
end
transaction(dbs, opts=OPTS, &block) click to toggle source

Uses a transaction on all given databases with the given options. This:

Sequel.transaction([DB1, DB2, DB3]){}

is equivalent to:

DB1.transaction do
  DB2.transaction do
    DB3.transaction do
    end
  end
end

except that if Sequel::Rollback is raised by the block, the transaction is rolled back on all databases instead of just the last one.

Note that this method cannot guarantee that all databases will commit or rollback. For example, if DB3 commits but attempting to commit on DB2 fails (maybe because foreign key checks are deferred), there is no way to uncommit the changes on DB3. For that kind of support, you need to have two-phase commit/prepared transactions (which Sequel supports on some databases).

# File lib/sequel/core.rb, line 360
def transaction(dbs, opts=OPTS, &block)
  unless opts[:rollback]
    rescue_rollback = true
    opts = Hash[opts].merge!(:rollback=>:reraise)
  end
  pr = dbs.reverse.inject(block){|bl, db| proc{db.transaction(opts, &bl)}}
  if rescue_rollback
    begin
      pr.call
    rescue Sequel::Rollback
      nil
    end
  else
    pr.call
  end
end
typecast_to_application_timestamp(v) click to toggle source

Convert the given object into an object of Sequel.datetime_class in the application_timezone. Used when typecasting values when assigning them to model datetime attributes.

# File lib/sequel/timezones.rb, line 117
def typecast_to_application_timestamp(v)
  convert_timestamp(v, Sequel.typecast_timezone)
end
virtual_row(&block) click to toggle source

If the supplied block takes a single argument, yield an SQL::VirtualRow instance to the block argument. Otherwise, evaluate the block in the context of a SQL::VirtualRow instance.

Sequel.virtual_row{a} # Sequel::SQL::Identifier.new(:a)
Sequel.virtual_row{|o| o.a} # Sequel::SQL::Function.new(:a)
# File lib/sequel/core.rb, line 384
def virtual_row(&block)
  vr = VIRTUAL_ROW
  case block.arity
  when -1, 0
    vr.instance_exec(&block)
  else
    block.call(vr)
  end  
end

Private Instance Methods

_date_parse(string) click to toggle source

Return a hash of date information parsed from the given string.

# File lib/sequel/core.rb, line 397
def _date_parse(string)
  Date._parse(string)
end
adapter_method(adapter, *args, &block) click to toggle source

Helper method that the database adapter class methods that are added to Sequel via metaprogramming use to parse arguments.

# File lib/sequel/core.rb, line 403
def adapter_method(adapter, *args, &block)
  options = args.last.is_a?(Hash) ? args.pop : OPTS
  opts = {:adapter => adapter.to_sym}
  opts[:database] = args.shift if args.first.is_a?(String)
  if args.any?
    raise ::Sequel::Error, "Wrong format of arguments, either use (), (String), (Hash), or (String, Hash)"
  end

  connect(opts.merge(options), &block)
end
convert_input_datetime_no_offset(v, input_timezone) click to toggle source

Convert the given DateTime to the given input_timezone, keeping the same time and just modifying the timezone.

# File lib/sequel/timezones.rb, line 125
def convert_input_datetime_no_offset(v, input_timezone)
  case input_timezone
  when nil, :utc
    v # DateTime assumes UTC if no offset is given
  when :local
    offset = local_offset_for_datetime(v)
    v.new_offset(offset) - offset
  else
    convert_input_datetime_other(v, input_timezone)
  end
end
convert_input_datetime_other(v, input_timezone) click to toggle source

Convert the given DateTime to the given input_timezone that is not supported by default (i.e. one other than nil, :local, or :utc). Raises an InvalidValue by default. Can be overridden in extensions.

# File lib/sequel/timezones.rb, line 140
def convert_input_datetime_other(v, input_timezone)
  raise InvalidValue, "Invalid input_timezone: #{input_timezone.inspect}"
end
convert_input_time_other(v, input_timezone) click to toggle source

Convert the given Time to the given input_timezone that is not supported by default (i.e. one other than nil, :local, or :utc). Raises an InvalidValue by default. Can be overridden in extensions.

# File lib/sequel/timezones.rb, line 147
def convert_input_time_other(v, input_timezone)
  raise InvalidValue, "Invalid input_timezone: #{input_timezone.inspect}"
end
convert_input_timestamp(v, input_timezone) click to toggle source

Converts the object from a String, Array, Date, DateTime, or Time into an instance of Sequel.datetime_class. If given an array or a string that doesn't contain an offset, assume that the array/string is already in the given input_timezone.

# File lib/sequel/timezones.rb, line 154
def convert_input_timestamp(v, input_timezone)
  case v
  when String
    v2 = Sequel.string_to_datetime(v)
    if !input_timezone || _date_parse(v).has_key?(:offset)
      v2
    else
      # Correct for potentially wrong offset if string doesn't include offset
      if v2.is_a?(DateTime)
        convert_input_datetime_no_offset(v2, input_timezone)
      else
        case input_timezone
        when nil, :local
          v2
        when :utc
          (v2 + v2.utc_offset).utc
        else
          convert_input_time_other((v2 + v2.utc_offset).utc, input_timezone)
        end
      end
    end
  when Array
    y, mo, d, h, mi, s, ns, off = v
    if datetime_class == DateTime
      s += Rational(ns, 1000000000) if ns
      if off
        DateTime.civil(y, mo, d, h, mi, s, off)
      else
        convert_input_datetime_no_offset(DateTime.civil(y, mo, d, h, mi, s), input_timezone)
      end
    elsif off
      s += Rational(ns, 1000000000) if ns
      Time.new(y, mo, d, h, mi, s, (off*86400).to_i)
    else
      case input_timezone
      when nil, :local
        Time.local(y, mo, d, h, mi, s, (ns ? ns / 1000.0 : 0))
      when :utc
        Time.utc(y, mo, d, h, mi, s, (ns ? ns / 1000.0 : 0))
      else
        convert_input_time_other(Time.utc(y, mo, d, h, mi, s, (ns ? ns / 1000.0 : 0)), input_timezone)
      end
    end
  when Hash
    ary = [:year, :month, :day, :hour, :minute, :second, :nanos].map{|x| (v[x] || v[x.to_s]).to_i}
    if (offset = (v[:offset] || v['offset']))
      ary << offset
    end
    convert_input_timestamp(ary, input_timezone)
  when Time
    if datetime_class == DateTime
      v.to_datetime
    else
      v
    end
  when DateTime
    if datetime_class == DateTime
      v
    else
      v.to_time
    end
  else
    raise InvalidValue, "Invalid convert_input_timestamp type: #{v.inspect}"
  end
end
convert_output_datetime_other(v, output_timezone) click to toggle source

Convert the given DateTime to the given output_timezone that is not supported by default (i.e. one other than nil, :local, or :utc). Raises an InvalidValue by default. Can be overridden in extensions.

# File lib/sequel/timezones.rb, line 223
def convert_output_datetime_other(v, output_timezone)
  raise InvalidValue, "Invalid output_timezone: #{output_timezone.inspect}"
end
convert_output_time_other(v, output_timezone) click to toggle source

Convert the given Time to the given output_timezone that is not supported by default (i.e. one other than nil, :local, or :utc). Raises an InvalidValue by default. Can be overridden in extensions.

# File lib/sequel/timezones.rb, line 230
def convert_output_time_other(v, output_timezone)
  raise InvalidValue, "Invalid output_timezone: #{output_timezone.inspect}"
end
convert_timezone_setter_arg(tz) click to toggle source

Convert the timezone setter argument. Returns argument given by default, exists for easier overriding in extensions.

# File lib/sequel/timezones.rb, line 236
def convert_timezone_setter_arg(tz)
  tz
end
local_offset_for_datetime(dt) click to toggle source

Takes a DateTime dt, and returns the correct local offset for that dt, daylight savings included, in fraction of a day.

# File lib/sequel/timezones.rb, line 241
def local_offset_for_datetime(dt)
  time_offset_to_datetime_offset Time.local(dt.year, dt.month, dt.day, dt.hour, dt.min, dt.sec).utc_offset
end
time_offset_to_datetime_offset(offset_secs) click to toggle source

Caches offset conversions to avoid excess Rational math.

# File lib/sequel/timezones.rb, line 246
def time_offset_to_datetime_offset(offset_secs)
  if offset = Sequel.synchronize{@local_offsets[offset_secs]}
    return offset
  end
  Sequel.synchronize{@local_offsets[offset_secs] = Rational(offset_secs, 86400)}
end