module Sequel::Model::InstanceMethods

  1. lib/sequel/model/base.rb

Sequel::Model instance methods that implement basic model functionality.

  • All of the model before/after/around hooks are implemented as instance methods that are called by Sequel when the appropriate action occurs. For example, when destroying a model object, Sequel will call around_destroy, which will call before_destroy, do the destroy, and then call after_destroy.

  • The following instance_methods all call the class method of the same name: columns, db, primary_key, db_schema.

  • The following accessor methods are defined via metaprogramming: raise_on_save_failure, raise_on_typecast_failure, require_modification, strict_param_setting, typecast_empty_string_to_nil, typecast_on_assignment, and use_transactions. The setter methods will change the setting for the instance, and the getter methods will check for an instance setting, then try the class setting if no instance setting has been set.

Public Instance Aliases

pk_equal? -> ===

If the receiver has a primary key value, returns true if the objects have the same class and primary key value. If the receiver’s primary key value is nil or is an array containing nil, returns false.

Artist[1].pk_equal?(Artist[1]) # => true # => false
Artist[1].set(name: 'Bob').pk_equal?(Artist[1]) # => true


to_hash [R]

The hash of attribute values. Keys are symbols with the names of the underlying database columns. The returned hash is a reference to the receiver’s values hash, and modifying it will also modify the receiver’s values. 'Bob').values # => {:name=>'Bob'}
Artist[1].values # => {:id=>1, :name=>'Jim', ...}
values [R]

The hash of attribute values. Keys are symbols with the names of the underlying database columns. The returned hash is a reference to the receiver’s values hash, and modifying it will also modify the receiver’s values. 'Bob').values # => {:name=>'Bob'}
Artist[1].values # => {:id=>1, :name=>'Jim', ...}

Public Class methods

new(values = OPTS)

Creates new instance and passes the given values to set. If a block is given, yield the instance to the block.



should be a hash to pass to set. 'Bob') do |a| = 'Bob'
[show source]
     # File lib/sequel/model/base.rb
1099 def initialize(values = OPTS)
1100   @values = {}
1101   @new = true
1102   @modified = true
1103   initialize_set(values)
1104   _clear_changed_columns(:initialize)
1105   yield self if defined?(yield)
1106 end

Public Instance methods


Alias of eql?

[show source]
     # File lib/sequel/model/base.rb
1136 def ==(obj)
1137   eql?(obj)
1138 end

Case equality. By default, checks equality of the primary key value, see pk_equal?.

Artist[1] === Artist[1] # => true === # => false
Artist[1].set(name: 'Bob') === Artist[1] # => true
[show source]
     # File lib/sequel/model/base.rb
1146 def ===(obj)
1147   case pkv = pk
1148   when nil
1149     return false
1150   when Array
1151     return false if pkv.any?(&:nil?)
1152   end
1154   (obj.class == model) && ( == pkv)
1155 end

Returns value of the column’s attribute.

Artist[1][:id] #=> 1
[show source]
     # File lib/sequel/model/base.rb
1111 def [](column)
1112   @values[column]
1113 end
[]=(column, value)

Sets the value for the given column. If typecasting is enabled for this object, typecast the value based on the column’s type. If this is a new record or the typecasted value isn’t the same as the current value for the column, mark the column as changed.

a =
a[:name] = 'Bob'
a.values #=> {:name=>'Bob'}
[show source]
     # File lib/sequel/model/base.rb
1123 def []=(column, value)
1124   # If it is new, it doesn't have a value yet, so we should
1125   # definitely set the new value.
1126   # If the column isn't in @values, we can't assume it is
1127   # NULL in the database, so assume it has changed.
1128   v = typecast_value(column, value)
1129   vals = @values
1130   if new? || !vals.include?(column) || v != (c = vals[column]) || v.class != c.class
1131     change_column_value(column, v)
1132   end
1133 end

The autoincrementing primary key for this model object. Should be overridden if you have a composite primary key with one part of it being autoincrementing.

[show source]
     # File lib/sequel/model/base.rb
1178 def autoincrementing_primary_key
1179   primary_key
1180 end

Cancel the current action. Should be called in before hooks to halt the processing of the action. If a msg argument is given and the model instance is configured to raise exceptions on failure, sets the message to use for the raised HookFailed exception.

[show source]
     # File lib/sequel/model/base.rb
1186 def cancel_action(msg=nil)
1187   raise_hook_failure(msg)
1188 end

The columns that have been updated. This isn’t completely accurate, as it could contain columns whose values have not changed.

a = Artist[1]
a.changed_columns # => [] = 'Bob'
a.changed_columns # => [:name]
[show source]
     # File lib/sequel/model/base.rb
1197 def changed_columns
1198   _changed_columns
1199 end

Deletes and returns self. Does not run destroy hooks. Look into using destroy instead.

Artist[1].delete # DELETE FROM artists WHERE (id = 1)
# => #<Artist {:id=>1, ...}>
[show source]
     # File lib/sequel/model/base.rb
1206 def delete
1207   raise Sequel::Error, "can't delete frozen object" if frozen?
1208   _delete
1209   self
1210 end
destroy(opts = OPTS)

Like delete but runs hooks before and after delete. Uses a transaction if use_transactions is true or if the :transaction option is given and true.

Artist[1].destroy # BEGIN; DELETE FROM artists WHERE (id = 1); COMMIT;
# => #<Artist {:id=>1, ...}>
[show source]
     # File lib/sequel/model/base.rb
1218 def destroy(opts = OPTS)
1219   raise Sequel::Error, "can't destroy frozen object" if frozen?
1220   checked_save_failure(opts){checked_transaction(opts){_destroy(opts)}}
1221 end

Iterates through all of the current values using each.

Album[1].each{|k, v| puts "#{k} => #{v}"}
# id => 1
# name => 'Bob'
[show source]
     # File lib/sequel/model/base.rb
1228 def each(&block)
1229   @values.each(&block)
1230 end

Compares model instances by values.

Artist[1] == Artist[1] # => true == # => true
Artist[1].set(name: 'Bob') == Artist[1] # => false
[show source]
     # File lib/sequel/model/base.rb
1237 def eql?(obj)
1238   (obj.class == model) && (obj.values == @values)
1239 end

Returns the validation errors associated with this object. See Errors.

[show source]
     # File lib/sequel/model/base.rb
1243 def errors
1244   @errors ||=
1245 end

Returns true when current instance exists, false otherwise. Generally an object that isn’t new will exist unless it has been deleted. Uses a database query to check for existence, unless the model object is new, in which case this is always false.

Artist[1].exists? # SELECT 1 FROM artists WHERE (id = 1)
# => true
# => false
[show source]
     # File lib/sequel/model/base.rb
1257 def exists?
1258   new? ? false : !this.get(, :one)).nil?
1259 end

Ignore the model’s setter method cache when this instances extends a module, as the module may contain setter methods.

[show source]
     # File lib/sequel/model/base.rb
1263 def extend(mod)
1264   @singleton_setter_added = true
1265   super
1266 end

Freeze the object in such a way that it is still usable but not modifiable. Once an object is frozen, you cannot modify it’s values, changed_columns, errors, or dataset.

[show source]
     # File lib/sequel/model/base.rb
1271 def freeze
1272   unless errors.frozen?
1273     validate
1274     errors.freeze
1275   end
1276   values.freeze
1277   _changed_columns.freeze
1278   this if !new? && model.primary_key
1279   super
1280 end

Value that should be unique for objects with the same class and pk (if pk is not nil), or the same class and values (if pk is nil).

Artist[1].hash == Artist[1].hash # true
Artist[1].set(name: 'Bob').hash == Artist[1].hash # true == # true 'Bob').hash == # false
[show source]
     # File lib/sequel/model/base.rb
1289 def hash
1290   case primary_key
1291   when Array
1292     [model, !pk.all? ? @values : pk].hash
1293   when Symbol
1294     [model, pk.nil? ? @values : pk].hash
1295   else
1296     [model, @values].hash
1297   end
1298 end

Returns value for the :id attribute, even if the primary key is not id. To get the primary key value, use pk.

Artist[1].id # => 1
[show source]
     # File lib/sequel/model/base.rb
1304 def id
1305   @values[:id]
1306 end

Returns a string representation of the model instance including the class name and values.

[show source]
     # File lib/sequel/model/base.rb
1310 def inspect
1311   "#<#{} @values=#{inspect_values}>"
1312 end

Returns the keys in values. May not include all column names. # => [] 'Bob').keys # => [:name]
Artist[1].keys # => [:id, :name]
[show source]
     # File lib/sequel/model/base.rb
1319 def keys
1320   @values.keys
1321 end

Refresh this record using for_update (by default, or the specified style when given) unless this is a new record. Returns self. This can be used to make sure no other process is updating the record at the same time.

If style is a string, it will be used directly. You should never pass a string to this method that is derived from user input, as that can lead to SQL injection.

A symbol may be used for database independent locking behavior, but all supported symbols have separate methods (e.g. for_update).

a = Artist[1]
Artist.db.transaction do
  a.update(name: 'A')

a = Artist[2]
Artist.db.transaction do
  a.lock!('FOR NO KEY UPDATE')
  a.update(name: 'B')
[show source]
     # File lib/sequel/model/base.rb
1346 def lock!(style=:update)
1347   _refresh(this.lock_style(style)) unless new?
1348   self
1349 end

Remove elements of the model object that make marshalling fail. Returns self.

a = Artist[1]
[show source]
     # File lib/sequel/model/base.rb
1356 def marshallable!
1357   @this = nil
1358   self
1359 end

Explicitly mark the object as modified, so save_changes/update will run callbacks even if no columns have changed.

a = Artist[1]
a.save_changes # No callbacks run, as no changes
a.save_changes # Callbacks run, even though no changes made

If a column is given, specifically marked that column as modified, so that save_changes/update will include that column in the update. This should be used if you plan on mutating the column value instead of assigning a new column value:

a.modified!(:name)!(/[aeou]/, 'i')
[show source]
     # File lib/sequel/model/base.rb
1376 def modified!(column=nil)
1377   _add_changed_column(column) if column
1378   @modified = true
1379 end

Whether this object has been modified since last saved, used by save_changes to determine whether changes should be saved. New values are always considered modified.

a = Artist[1]
a.modified? # => false
a.set(name: 'Jim')
a.modified? # => true

If a column is given, specifically check if the given column has been modified:

a.modified?(:num_albums) # => false
a.num_albums = 10
a.modified?(:num_albums) # => true
[show source]
     # File lib/sequel/model/base.rb
1396 def modified?(column=nil)
1397   if column
1398     changed_columns.include?(column)
1399   else
1400     @modified || !changed_columns.empty?
1401   end
1402 end

Returns true if the current instance represents a new record. # => true
Artist[1].new? # => false
[show source]
     # File lib/sequel/model/base.rb
1408 def new?
1409   defined?(@new) ? @new : (@new = false)
1410 end

Returns the primary key value identifying the model instance. Raises an Error if this model does not have a primary key. If the model has a composite primary key, returns an array of values.

Artist[1].pk # => 1
Artist[[1, 2]].pk # => [1, 2]
[show source]
     # File lib/sequel/model/base.rb
1418 def pk
1419   raise(Error, "No primary key is associated with this model") unless key = primary_key
1420   if key.is_a?(Array)
1421     vals = @values
1422{|k| vals[k]}
1423   else
1424     @values[key]
1425   end
1426 end

Returns a hash mapping the receivers primary key column(s) to their values.

Artist[1].pk_hash # => {:id=>1}
Artist[[1, 2]].pk_hash # => {:id1=>1, :id2=>2}
[show source]
     # File lib/sequel/model/base.rb
1432 def pk_hash
1433   model.primary_key_hash(pk)
1434 end

Returns a hash mapping the receivers qualified primary key column(s) to their values.

# => {Sequel[:artists][:id]=>1}
Artist[[1, 2]].qualified_pk_hash
# => {Sequel[:artists][:id1]=>1, Sequel[:artists][:id2]=>2}
[show source]
     # File lib/sequel/model/base.rb
1442 def qualified_pk_hash(qualifier=model.table_name)
1443   model.qualified_primary_key_hash(pk, qualifier)
1444 end

Reloads attributes from database and returns self. Also clears all changed_columns information. Raises an Error if the record no longer exists in the database.

a = Artist[1] = 'Jim'
a.refresh # => 'Bob'
[show source]
     # File lib/sequel/model/base.rb
1454 def refresh
1455   raise Sequel::Error, "can't refresh frozen object" if frozen?
1456   _refresh(this)
1457   self
1458 end

Alias of refresh, but not aliased directly to make overriding in a plugin easier.

[show source]
     # File lib/sequel/model/base.rb
1461 def reload
1462   refresh
1463 end

Creates or updates the record, after making sure the record is valid and before hooks execute successfully. Fails if:

  • the record is not valid, or

  • before_save calls cancel_action, or

  • the record is new and before_create calls cancel_action, or

  • the record is not new and before_update calls cancel_action.

If save fails and either raise_on_save_failure or the :raise_on_failure option is true, it raises ValidationFailed or HookFailed. Otherwise it returns nil.

If it succeeds, it returns self.

Takes the following options:


save all changed columns, instead of all columns or the columns given


array of specific columns that should be saved.


set to true or false to override the current raise_on_save_failure setting


set the server/shard on the object before saving, and use that server/shard in any transaction.


set to true or false to override the current use_transactions setting


set to false to skip validation

[show source]
     # File lib/sequel/model/base.rb
1490 def save(opts=OPTS)
1491   raise Sequel::Error, "can't save frozen object" if frozen?
1492   set_server(opts[:server]) if opts[:server] 
1493   unless _save_valid?(opts)
1494     raise(validation_failed_error) if raise_on_failure?(opts)
1495     return
1496   end
1497   checked_save_failure(opts){checked_transaction(opts){_save(opts)}}
1498 end

Saves only changed columns if the object has been modified. If the object has not been modified, returns nil. If unable to save, returns false unless raise_on_save_failure is true.

a = Artist[1]
a.save_changes # => nil = 'Jim'
a.save_changes # UPDATE artists SET name = 'Bob' WHERE (id = 1)
# => #<Artist {:id=>1, :name=>'Jim', ...}
[show source]
     # File lib/sequel/model/base.rb
1509 def save_changes(opts=OPTS)
1510   save(Hash[opts].merge!(:changed=>true)) || false if modified? 
1511 end

Updates the instance with the supplied values with support for virtual attributes, raising an exception if a value is used that doesn’t have a setter method (or ignoring it if strict_param_setting = false). Does not save the record.

artist.set(name: 'Jim') # => 'Jim'
[show source]
     # File lib/sequel/model/base.rb
1520 def set(hash)
1521   set_restricted(hash, :default)
1522 end
set_fields(hash, fields, opts=nil)

For each of the fields in the given array fields, call the setter method with the value of that hash entry for the field. Returns self.

You can provide an options hash, with the following options currently respected:


Can be set to :skip to skip missing entries or :raise to raise an Error for missing entries. The default behavior is not to check for missing entries, in which case the default value is used. To be friendly with most web frameworks, the missing check will also check for the string version of the argument in the hash if given a symbol.


artist.set_fields({name: 'Jim'}, [:name]) # => 'Jim'

artist.set_fields({hometown: 'LA'}, [:name]) # => nil
artist.hometown # => 'Sac' # => 'Jim'
artist.set_fields({}, [:name], missing: :skip) # => 'Jim' # => 'Jim'
artist.set_fields({}, [:name], missing: :raise)
# Sequel::Error raised
[show source]
     # File lib/sequel/model/base.rb
1550 def set_fields(hash, fields, opts=nil)
1551   opts = if opts
1552     model.default_set_fields_options.merge(opts)
1553   else
1554     model.default_set_fields_options
1555   end
1557   case missing = opts[:missing]
1558   when :skip, :raise
1559     do_raise = true if missing == :raise
1560     fields.each do |f|
1561       if hash.has_key?(f) 
1562         set_column_value("#{f}=", hash[f])
1563       elsif f.is_a?(Symbol) && hash.has_key?(sf = f.to_s)
1564         set_column_value("#{sf}=", hash[sf])
1565       elsif do_raise
1566         raise(Sequel::Error, "missing field in hash: #{f.inspect} not in #{hash.inspect}")
1567       end
1568     end
1569   else
1570     fields.each{|f| set_column_value("#{f}=", hash[f])}
1571   end
1572   self
1573 end

Set the shard that this object is tied to. Returns self.

[show source]
     # File lib/sequel/model/base.rb
1576 def set_server(s)
1577   @server = s
1578   @this = @this.server(s) if @this
1579   self
1580 end

Clear the setter_methods cache when a method is added

[show source]
     # File lib/sequel/model/base.rb
1583 def singleton_method_added(meth)
1584   @singleton_setter_added = true if meth.to_s.end_with?('=')
1585   super
1586 end

Skip all validation of the object on the next call to save, including the running of validation hooks. This is designed for and should only be used in cases where valid? is called before saving and the validate: false option cannot be passed to save.

[show source]
     # File lib/sequel/model/base.rb
1593 def skip_validation_on_next_save!
1594   @skip_validation_on_next_save = true
1595 end

Returns (naked) dataset that should return only this instance.

# SELECT * FROM artists WHERE (id = 1) LIMIT 1
[show source]
     # File lib/sequel/model/base.rb
1601 def this
1602   return @this if @this
1603   raise Error, "No dataset for model #{model}" unless ds = model.instance_dataset
1604   @this = use_server(ds.where(pk_hash))
1605 end

Runs set with the passed hash and then runs save_changes.

artist.update(name: 'Jim') # UPDATE artists SET name = 'Jim' WHERE (id = 1)
[show source]
     # File lib/sequel/model/base.rb
1610 def update(hash)
1611   update_restricted(hash, :default)
1612 end
update_fields(hash, fields, opts=nil)

Update the instance’s values by calling set_fields with the arguments, then calls save_changes.

artist.update_fields({name: 'Jim'}, [:name])
# UPDATE artists SET name = 'Jim' WHERE (id = 1)

artist.update_fields({hometown: 'LA'}, [:name])
# UPDATE artists SET name = NULL WHERE (id = 1)
[show source]
     # File lib/sequel/model/base.rb
1622 def update_fields(hash, fields, opts=nil)
1623   set_fields(hash, fields, opts)
1624   save_changes
1625 end
valid?(opts = OPTS)

Validates the object and returns true if no errors are reported.

artist.set(name: 'Valid').valid? # => true
artist.set(name: 'Invalid').valid? # => false
artist.errors.full_messages # => ['name cannot be Invalid']
[show source]
     # File lib/sequel/model/base.rb
1641 def valid?(opts = OPTS)
1642   _valid?(opts)
1643 rescue HookFailed
1644   false
1645 end

Validates the object. If the object is invalid, errors should be added to the errors attribute. By default, does nothing, as all models are valid by default. See the “Model Validations” guide. for details about validation. Should not be called directly by user code, call valid? instead to check if an object is valid.

[show source]
     # File lib/sequel/model/base.rb
1633 def validate
1634 end