module Sequel::Timezones

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)

Source

   # File lib/sequel/timezones.rb
50 def application_to_database_timestamp(v)
51   convert_output_timestamp(v, Sequel.database_timezone)
52 end

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

array_or_set_join (obj, arg)

Source

    # File lib/sequel/core.rb
170 def array_or_set_join(obj, arg)
171   obj.join(arg)
172 end

Join the array or set.

condition_specifier? (obj)

Source

   # File lib/sequel/core.rb
84 def condition_specifier?(obj)
85   case obj
86   when Hash
87     true
88   when Array
89     !obj.empty? && !obj.is_a?(SQL::ValueList) && obj.all?{|i| i.is_a?(Array) && (i.length == 2)}
90   else
91     false
92   end
93 end

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

connect (*args, &block)

Source

    # File lib/sequel/core.rb
124 def connect(*args, &block)
125   Database.connect(*args, &block)
126 end

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.

convert_exception_class (exception, klass)

Source

    # File lib/sequel/core.rb
137 def convert_exception_class(exception, klass)
138   return exception if exception.is_a?(klass)
139   e = klass.new("#{exception.class}: #{exception.message}")
140   e.wrapped_exception = exception
141   e.set_backtrace(exception.backtrace)
142   e
143 end

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.

convert_output_timestamp (v, output_timezone)

Source

   # File lib/sequel/timezones.rb
55 def convert_output_timestamp(v, output_timezone)
56   if output_timezone
57     if v.is_a?(DateTime)
58       case output_timezone
59       when :utc
60         v.new_offset(0)
61       when :local
62         v.new_offset(local_offset_for_datetime(v))
63       else
64         convert_output_datetime_other(v, output_timezone)
65       end
66     else
67       case output_timezone
68       when :utc
69         v.getutc
70       when :local
71         v.getlocal
72       else
73         convert_output_time_other(v, output_timezone)
74       end
75     end
76   else
77     v
78   end
79 end

Converts the object to the given output_timezone.

convert_timestamp (v, input_timezone)

Source

   # File lib/sequel/timezones.rb
84 def convert_timestamp(v, input_timezone)
85   if v.is_a?(Date) && !v.is_a?(DateTime)
86     # Dates handled specially as they are assumed to already be in the application_timezone
87     if datetime_class == DateTime
88       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)
89     else
90       Time.public_send(application_timezone == :utc ? :utc : :local, v.year, v.month, v.day)
91     end
92   else
93     convert_output_timestamp(convert_input_timestamp(v, input_timezone), application_timezone)
94   end
95 rescue InvalidValue
96   raise
97 rescue => e
98   raise convert_exception_class(e, InvalidValue)
99 end

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

core_extensions? ()

Source

    # File lib/sequel/core.rb
130 def core_extensions?
131   false
132 end

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

current ()

Source

    # File lib/sequel/core.rb
146 def current
147   Thread.current
148 end

The current concurrency primitive, Thread.current by default.

database_to_application_timestamp (v)

Source

    # File lib/sequel/timezones.rb
104 def database_to_application_timestamp(v)
105   convert_timestamp(v, Sequel.database_timezone)
106 end

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.

default_timezone= (tz)

Source

    # File lib/sequel/timezones.rb
109 def default_timezone=(tz)
110   self.database_timezone = tz
111   self.application_timezone = tz
112   self.typecast_timezone = tz
113 end

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

elapsed_seconds_since (timer)

Source

    # File lib/sequel/core.rb
372 def elapsed_seconds_since(timer)
373   start_timer - timer
374 end

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

extension (*extensions)

Source

    # File lib/sequel/core.rb
158 def extension(*extensions)
159   extensions.each{|e| orig_require("sequel/extensions/#{e}")}
160 end

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)

json_parser_error_class ()

Source

    # File lib/sequel/core.rb
164 def json_parser_error_class
165   JSON::ParserError
166 end

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

object_to_json (obj, *args, &block)

Source

    # File lib/sequel/core.rb
199 def object_to_json(obj, *args, &block)
200   obj.to_json(*args, &block)
201 end

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

orig_require (files, subdir=nil)

SEQUEL6: Remove

Alias for: require

parse_json (json)

Source

    # File lib/sequel/core.rb
205 def parse_json(json)
206   JSON.parse(json, :create_additions=>false)
207 end

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

recursive_map (array, converter)

Source

    # File lib/sequel/core.rb
223 def recursive_map(array, converter)
224   array.map do |i|
225     if i.is_a?(Array)
226       recursive_map(i, converter)
227     elsif !i.nil?
228       converter.call(i)
229     end
230   end
231 end

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.

require (files, subdir=nil)

Source

    # File lib/sequel/core.rb
234 def require(files, subdir=nil)
235   # SEQUEL6: Remove
236   # Use Kernel.require_relative to work around JRuby 9.0 bug
237   # simplecov:disable
238   Array(files).each{|f| Kernel.require_relative "#{"#{subdir}/" if subdir}#{f}"}
239   # simplecov:enable
240   Sequel::Deprecation.deprecate("Sequel.require is deprecated and will be removed in Sequel 6.")
241 end

For backwards compatibility only. require_relative should be used instead.

Also aliased as: orig_require

set_temp_name (mod) { || ... }

Source

    # File lib/sequel/core.rb
185 def set_temp_name(mod)
186   mod.set_temporary_name(yield)
187   mod
188 end

Create a new module using the block, and set the temporary name on it using the given a containing module and name.

split_symbol (sym)

Source

    # File lib/sequel/core.rb
250 def split_symbol(sym)
251   # SEQUEL6.1: Remove
252   unless v = Sequel.synchronize{SPLIT_SYMBOL_CACHE[sym]}
253     if split_symbols?
254       v = case s = sym.to_s
255       when /\A((?:(?!__).)+)__((?:(?!___).)+)___(.+)\z/
256         [$1.freeze, $2.freeze, $3.freeze].freeze
257       when /\A((?:(?!___).)+)___(.+)\z/
258         [nil, $1.freeze, $2.freeze].freeze
259       when /\A((?:(?!__).)+)__(.+)\z/
260         [$1.freeze, $2.freeze, nil].freeze
261       else
262         [nil, s.freeze, nil].freeze
263       end
264     else
265       v = [nil,sym.to_s.freeze,nil].freeze
266     end
267     Sequel.synchronize{SPLIT_SYMBOL_CACHE[sym] = v}
268   end
269   v
270 end

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 behind 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.

split_symbols= (v)

Source

    # File lib/sequel/core.rb
302 def split_symbols=(v)
303   # SEQUEL6: Remove
304   Sequel.synchronize{SPLIT_SYMBOL_CACHE.clear}
305   @split_symbols = v
306 end

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 identifiers 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

split_symbols? ()

Source

    # File lib/sequel/core.rb
309 def split_symbols?
310   # SEQUEL6.1: Remove
311   @split_symbols
312 end

Whether Sequel currently splits symbols into qualified/aliased identifiers.

start_timer ()

Source

    # File lib/sequel/core.rb
359 def start_timer
360   Process.clock_gettime(Process::CLOCK_MONOTONIC)
361 end

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

string_to_date (string)

Source

    # File lib/sequel/core.rb
317 def string_to_date(string)
318   Date.parse(string, Sequel.convert_two_digit_years)
319 rescue => e
320   raise convert_exception_class(e, InvalidValue)
321 end

Converts the given string into a Date object.

Sequel.string_to_date('2010-09-10') # Date.civil(2010, 09, 10)

string_to_datetime (string)

Source

    # File lib/sequel/core.rb
327 def string_to_datetime(string)
328   if datetime_class == DateTime
329     DateTime.parse(string, convert_two_digit_years)
330   else
331     datetime_class.parse(string)
332   end
333 rescue => e
334   raise convert_exception_class(e, InvalidValue)
335 end

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)

string_to_time (string)

Source

    # File lib/sequel/core.rb
341 def string_to_time(string)
342   SQLTime.parse(string)
343 rescue => e
344   raise convert_exception_class(e, InvalidValue)
345 end

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'

synchronize () { |: synchronize(&block)| ... }

Source

    # File lib/sequel/core.rb
352 def synchronize(&block)
353   @single_threaded ? yield : @data_mutex.synchronize(&block)
354 end

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.

synchronize_with (mutex) { || ... }

Source

    # File lib/sequel/core.rb
212 def synchronize_with(mutex)
213   if mutex
214     mutex.synchronize{yield}
215   else
216     yield
217   end
218 end

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.

transaction (dbs, opts=OPTS, &block)

Source

    # File lib/sequel/core.rb
398 def transaction(dbs, opts=OPTS, &block)
399   unless opts[:rollback]
400     rescue_rollback = true
401     opts = Hash[opts].merge!(:rollback=>:reraise)
402   end
403   pr = dbs.reverse.inject(block){|bl, db| proc{db.transaction(opts, &bl)}}
404   if rescue_rollback
405     begin
406       pr.call
407     rescue Sequel::Rollback
408       nil
409     end
410   else
411     pr.call
412   end
413 end

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).

typecast_to_application_timestamp (v)

Source

    # File lib/sequel/timezones.rb
118 def typecast_to_application_timestamp(v)
119   convert_timestamp(v, Sequel.typecast_timezone)
120 end

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.

virtual_row () { |vr| ... }

Source

    # File lib/sequel/core.rb
422 def virtual_row(&block)
423   vr = VIRTUAL_ROW
424   case block.arity
425   when -1, 0
426     vr.instance_exec(&block)
427   else
428     yield(vr)
429   end  
430 end

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)

Private Instance Methods

_date_parse (string)

Source

    # File lib/sequel/core.rb
435 def _date_parse(string)
436   Date._parse(string)
437 end

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

adapter_method (adapter, *args, &block)

Source

    # File lib/sequel/core.rb
441 def adapter_method(adapter, *args, &block)
442   options = args.last.is_a?(Hash) ? args.pop : OPTS
443   opts = {:adapter => adapter.to_sym}
444   opts[:database] = args.shift if args.first.is_a?(String)
445   if args.any?
446     raise ::Sequel::Error, "Wrong format of arguments, either use (), (String), (Hash), or (String, Hash)"
447   end
448 
449   connect(opts.merge(options), &block)
450 end

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

convert_input_datetime_no_offset (v, input_timezone)

Source

    # File lib/sequel/timezones.rb
126 def convert_input_datetime_no_offset(v, input_timezone)
127   case input_timezone
128   when nil, :utc
129     v # DateTime assumes UTC if no offset is given
130   when :local
131     offset = local_offset_for_datetime(v)
132     v.new_offset(offset) - offset
133   else
134     convert_input_datetime_other(v, input_timezone)
135   end
136 end

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

convert_input_datetime_other (v, input_timezone)

Source

    # File lib/sequel/timezones.rb
141 def convert_input_datetime_other(v, input_timezone)
142   raise InvalidValue, "Invalid input_timezone: #{input_timezone.inspect}"
143 end

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.

convert_input_time_other (v, input_timezone)

Source

    # File lib/sequel/timezones.rb
148 def convert_input_time_other(v, input_timezone)
149   raise InvalidValue, "Invalid input_timezone: #{input_timezone.inspect}"
150 end

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.

convert_input_timestamp (v, input_timezone)

Source

    # File lib/sequel/timezones.rb
155 def convert_input_timestamp(v, input_timezone)
156   case v
157   when String
158     v2 = Sequel.string_to_datetime(v)
159     if !input_timezone || _date_parse(v).has_key?(:offset)
160       v2
161     else
162       # Correct for potentially wrong offset if string doesn't include offset
163       if v2.is_a?(DateTime)
164         convert_input_datetime_no_offset(v2, input_timezone)
165       else
166         case input_timezone
167         when nil, :local
168           v2
169         when :utc
170           (v2 + v2.utc_offset).utc
171         else
172           convert_input_time_other((v2 + v2.utc_offset).utc, input_timezone)
173         end
174       end
175     end
176   when Array
177     y, mo, d, h, mi, s, ns, off = v
178     if datetime_class == DateTime
179       s += Rational(ns, 1000000000) if ns
180       if off
181         DateTime.civil(y, mo, d, h, mi, s, off)
182       else
183         convert_input_datetime_no_offset(DateTime.civil(y, mo, d, h, mi, s), input_timezone)
184       end
185     elsif off
186       s += Rational(ns, 1000000000) if ns
187       Time.new(y, mo, d, h, mi, s, (off*86400).to_i)
188     else
189       case input_timezone
190       when nil, :local
191         Time.local(y, mo, d, h, mi, s, (ns ? ns / 1000.0 : 0))
192       when :utc
193         Time.utc(y, mo, d, h, mi, s, (ns ? ns / 1000.0 : 0))
194       else
195         convert_input_time_other(Time.utc(y, mo, d, h, mi, s, (ns ? ns / 1000.0 : 0)), input_timezone)
196       end
197     end
198   when Hash
199     ary = [:year, :month, :day, :hour, :minute, :second, :nanos].map{|x| (v[x] || v[x.to_s]).to_i}
200     if (offset = (v[:offset] || v['offset']))
201       ary << offset
202     end
203     convert_input_timestamp(ary, input_timezone)
204   when Time
205     if datetime_class == DateTime
206       v.to_datetime
207     else
208       v
209     end
210   when DateTime
211     if datetime_class == DateTime
212       v
213     else
214       v.to_time
215     end
216   else
217     raise InvalidValue, "Invalid convert_input_timestamp type: #{v.inspect}"
218   end
219 end

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.

convert_output_datetime_other (v, output_timezone)

Source

    # File lib/sequel/timezones.rb
224 def convert_output_datetime_other(v, output_timezone)
225   raise InvalidValue, "Invalid output_timezone: #{output_timezone.inspect}"
226 end

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.

convert_output_time_other (v, output_timezone)

Source

    # File lib/sequel/timezones.rb
231 def convert_output_time_other(v, output_timezone)
232   raise InvalidValue, "Invalid output_timezone: #{output_timezone.inspect}"
233 end

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.

convert_timezone_setter_arg (tz)

Source

    # File lib/sequel/timezones.rb
237 def convert_timezone_setter_arg(tz)
238   tz
239 end

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

local_offset_for_datetime (dt)

Source

    # File lib/sequel/timezones.rb
242 def local_offset_for_datetime(dt)
243   time_offset_to_datetime_offset Time.local(dt.year, dt.month, dt.day, dt.hour, dt.min, dt.sec).utc_offset
244 end

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

time_offset_to_datetime_offset (offset_secs)

Source

    # File lib/sequel/timezones.rb
247 def time_offset_to_datetime_offset(offset_secs)
248   if offset = Sequel.synchronize{@local_offsets[offset_secs]}
249     return offset
250   end
251   Sequel.synchronize{@local_offsets[offset_secs] = Rational(offset_secs, 86400)}
252 end

Caches offset conversions to avoid excess Rational math.