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.


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 = {})

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, line 1057
def initialize(values = {})
  @values = {}
  @new = true
  @modified = true
  yield self if block_given?

Public Instance methods

== (obj)

Alias of eql?

[show source]
# File lib/sequel/model/base.rb, line 1094
def ==(obj)
=== (obj)

If pk is not nil, true only if the objects have the same class and pk. If pk is nil, false.

Artist[1] === Artist[1] # true === # false
Artist[1].set(:name=>'Bob') == Artist[1] # => true
[show source]
# File lib/sequel/model/base.rb, line 1104
def ===(obj)
  pk.nil? ? false : (obj.class == model) && ( == pk)
[] (column)

Returns value of the column's attribute.

Artist[1][:id] #=> 1
[show source]
# File lib/sequel/model/base.rb, line 1069
def [](column)
[]= (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, line 1081
def []=(column, value)
  # If it is new, it doesn't have a value yet, so we should
  # definitely set the new value.
  # If the column isn't in @values, we can't assume it is
  # NULL in the database, so assume it has changed.
  v = typecast_value(column, value)
  vals = @values
  if new? || !vals.include?(column) || v != (c = vals[column]) || v.class != c.class
    change_column_value(column, v)
autoincrementing_primary_key ()

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, line 1119
def autoincrementing_primary_key
cancel_action (msg=nil)

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, line 1127
def cancel_action(msg=nil)
changed_columns ()

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, line 1138
def changed_columns
  @changed_columns ||= []
delete ()

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, line 1147
def delete
  raise Sequel::Error, "can't delete frozen object" if frozen?
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, line 1159
def destroy(opts = OPTS)
  raise Sequel::Error, "can't destroy frozen object" if frozen?
each (&block)

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, line 1169
def each(&block)
eql? (obj)

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, line 1178
def eql?(obj)
  (obj.class == model) && (obj.values == @values)
errors ()

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

[show source]
# File lib/sequel/model/base.rb, line 1184
def errors
  @errors ||=
exists? ()

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, line 1198
def exists?
  new? ? false : !this.get(, :one)).nil?
extend (mod)

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, line 1204
def extend(mod)
  @singleton_setter_added = true
freeze ()

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, line 1212
def freeze
  unless errors.frozen?
  this if !new? && model.primary_key
hash ()

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, line 1230
def hash
  case primary_key
  when Array
    [model, !pk.all? ? @values : pk].hash
  when Symbol
    [model, pk.nil? ? @values : pk].hash
    [model, @values].hash
id ()

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, line 1245
def id
inspect ()

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

[show source]
# File lib/sequel/model/base.rb, line 1251
def inspect
  "#<#{} @values=#{inspect_values}>"
keys ()

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, line 1260
def keys
lock! (style=:update)

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 = Artist[2]
Artist.db.transaction do
  a.lock!('FOR NO KEY UPDATE')
[show source]
# File lib/sequel/model/base.rb, line 1287
def lock!(style=:update)
  _refresh(this.lock_style(style)) unless new?
marshallable! ()

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

a = Artist[1]
[show source]
# File lib/sequel/model/base.rb, line 1297
def marshallable!
  @this = nil
modified! (column=nil)

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, line 1317
def modified!(column=nil)
  if column && !changed_columns.include?(column)
    changed_columns << column
  @modified = true
modified? (column=nil)

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, line 1339
def modified?(column=nil)
  if column
    @modified || !changed_columns.empty?
new? ()

Returns true if the current instance represents a new record. # => true
Artist[1].new? # => false
[show source]
# File lib/sequel/model/base.rb, line 1351
def new?
  defined?(@new) ? @new : (@new = false)
pk ()

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, line 1361
def pk
  raise(Error, "No primary key is associated with this model") unless key = primary_key
  if key.is_a?(Array)
    vals = @values{|k| vals[k]}
pk_hash ()

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, line 1375
def pk_hash
qualified_pk_hash (qualifier=model.table_name)

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, line 1385
def qualified_pk_hash(qualifier=model.table_name)
  model.qualified_primary_key_hash(pk, qualifier)
refresh ()

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, line 1397
def refresh
  raise Sequel::Error, "can't refresh frozen object" if frozen?
reload ()

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

[show source]
# File lib/sequel/model/base.rb, line 1404
def reload
save (opts=OPTS)

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 returns false, or

  • the record is new and before_create returns false, or

  • the record is not new and before_update returns false.

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, line 1433
def save(opts=OPTS)
  raise Sequel::Error, "can't save frozen object" if frozen?
  set_server(opts[:server]) if opts[:server] 
  unless checked_save_failure(opts){_valid?(opts)}
    raise( if raise_on_failure?(opts)
save_changes (opts=OPTS)

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, line 1452
def save_changes(opts=OPTS)
  save(Hash[opts].merge!(:changed=>true)) || false if modified? 
set (hash)

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, line 1463
def set(hash)
  set_restricted(hash, :default)
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, line 1493
def set_fields(hash, fields, opts=nil)
  opts = if opts

  case opts[:missing]
  when :skip
    fields.each do |f|
      if hash.has_key?(f) 
        set_column_value("#{f}=", hash[f])
      elsif f.is_a?(Symbol) && hash.has_key?(sf = f.to_s)
        set_column_value("#{sf}=", hash[sf])
  when :raise
    fields.each do |f|
      if hash.has_key?(f)
        set_column_value("#{f}=", hash[f])
      elsif f.is_a?(Symbol) && hash.has_key?(sf = f.to_s)
        set_column_value("#{sf}=", hash[sf])
        raise(Sequel::Error, "missing field in hash: #{f.inspect} not in #{hash.inspect}")
    fields.each{|f| set_column_value("#{f}=", hash[f])}
set_server (s)

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

[show source]
# File lib/sequel/model/base.rb, line 1526
def set_server(s)
  @server = s
  @this = @this.server(s) if @this
singleton_method_added (meth)

Clear the setter_methods cache when a method is added

[show source]
# File lib/sequel/model/base.rb, line 1533
def singleton_method_added(meth)
  @singleton_setter_added = true if meth.to_s.end_with?('=')
this ()

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, line 1542
def this
  return @this if @this
  raise Error, "No dataset for model #{model}" unless ds = model.instance_dataset
  @this = use_server(ds.where(pk_hash))
update (hash)

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, line 1551
def update(hash)
  update_restricted(hash, :default)
update_fields (hash, fields, opts=nil)

Update the instances values by calling set_fields with the arguments, then saves any changes to the record. Returns self.

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, line 1563
def update_fields(hash, fields, opts=nil)
  set_fields(hash, fields, opts)
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, line 1582
def valid?(opts = OPTS)
  rescue HookFailed
validate ()

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, line 1574
def validate