module Sequel::Model::ClassMethods

Class methods for Sequel::Model that implement basic model functionality.

All of the following methods have class methods created that send the method to the model’s dataset: all, any?, as_hash, as_set, avg, count, cross_join, distinct, each, each_server, empty?, except, exclude, exclude_having, fetch_rows, filter, first, first!, for_update, from, from_self, full_join, full_outer_join, get, graph, grep, group, group_and_count, group_append, group_by, having, import, inner_join, insert, intersect, invert, join, join_table, last, left_join, left_outer_join, limit, lock_style, map, max, min, multi_insert, naked, natural_full_join, natural_join, natural_left_join, natural_right_join, offset, order, order_append, order_by, order_more, order_prepend, paged_each, qualify, reverse, reverse_order, right_join, right_outer_join, select, select_all, select_append, select_group, select_hash, select_hash_groups, select_map, select_more, select_order_map, select_prepend, select_set, server, single_record, single_record!, single_value, single_value!, sum, to_hash, to_hash_groups, truncate, unfiltered, ungraphed, ungrouped, union, unlimited, unordered, where, where_all, where_each, where_single_value, with, with_recursive, with_sql

Attributes

Whether to cache the anonymous models created by Sequel::Model(), true by default. This is required for reloading them correctly (avoiding the superclass mismatch).

dataset_method_modules [R]

Array of modules that extend this model’s dataset. Stored so that if the model’s dataset is changed, it will be extended with all of these modules.

dataset_module_class [R]

The Module subclass to use for dataset_module blocks.

default_set_fields_options [RW]

The default options to use for Model#set_fields. These are merged with the options given to set_fields.

fast_instance_delete_sql [R]

SQL string fragment used for faster DELETE statement creation when deleting/destroying model instances, or nil if the optimization should not be used. For internal use only.

fast_pk_lookup_sql [R]

SQL string fragment used for faster lookups by primary key, or nil if the optimization should not be used. For internal use only.

instance_dataset [R]

The dataset that instance datasets (this) are based on. Generally a naked version of the model’s dataset limited to one row. For internal use only.

plugins [R]

Array of plugin modules loaded by this class

Sequel::Model.plugins
# => [Sequel::Model, Sequel::Model::Associations]

primary_key [R]

The primary key for the class. Sequel can determine this automatically for many databases, but not all, so you may need to set it manually. If not determined automatically, the default is :id.

raise_on_save_failure [RW]

Whether to raise an error instead of returning nil on a failure to save/create/save_changes/update/destroy due to a validation failure or a before_* hook returning false (default: true).

raise_on_typecast_failure [RW]

Whether to raise an error when unable to typecast data for a column (default: false). This should be set to true if you want to have model setter methods raise errors if the argument cannot be typecast properly.

require_modification [RW]

Whether to raise an error if an UPDATE or DELETE query related to a model instance does not modify exactly 1 row. If set to false, Sequel will not check the number of rows modified (default: true).

require_valid_table [RW]

If true (the default), requires that all models have valid tables, raising exceptions if creating a model without a valid table backing it. Setting this to false will allow the creation of model classes where the underlying table doesn’t exist.

simple_pk [R]

Should be the literal primary key column name if this Model’s table has a simple primary key, or nil if the model has a compound primary key or no primary key.

simple_table [R]

Should be the literal table name if this Model’s dataset is a simple table (no select, order, join, etc.), or nil otherwise. This and simple_pk are used for an optimization in Model[].

strict_param_setting [RW]

Whether mass assigning via .create/.new/#set/#update should raise an error if an invalid key is used. A key is invalid if no setter method exists for that key or the access to the setter method is restricted (e.g. due to it being a primary key field). If set to false, silently skip any key where the setter method doesn’t exist or access to it is restricted.

typecast_empty_string_to_nil [RW]

Whether to typecast the empty string (”) to nil for columns that are not string or blob. In most cases the empty string would be the way to specify a NULL SQL value in string form (nil.to_s == ”), and an empty string would not usually be typecast correctly for other types, so the default is true.

typecast_on_assignment [RW]

Whether to typecast attribute values on assignment (default: true). If set to false, no typecasting is done, so it will be left up to the database to typecast the value correctly.

use_transactions [RW]

Whether to use a transaction by default when saving/deleting records (default: true). If you are sending database queries in before_* or after_* hooks, you shouldn’t change the default setting without a good reason.

Public Instance Methods

[] (*args)

Source

    # File lib/sequel/model/base.rb
214 def [](*args)
215   args = args.first if args.size <= 1
216   args.is_a?(Hash) ? first(args) : (primary_key_lookup(args) unless args.nil?)
217 end

Returns the first record from the database matching the conditions. If a hash is given, it is used as the conditions. If another object is given, it finds the first record whose primary key(s) match the given argument(s). If no object is returned by the dataset, returns nil.

Artist[1] # SELECT * FROM artists WHERE id = 1
# => #<Artist {:id=>1, ...}>

Artist[name: 'Bob'] # SELECT * FROM artists WHERE (name = 'Bob') LIMIT 1
# => #<Artist {:name=>'Bob', ...}>

Model (source)

Source

    # File lib/sequel/model/base.rb
181 def Model(source)
182   if cache_anonymous_models
183     cache = Sequel.synchronize{@Model_cache ||= {}}
184     if klass = Sequel.synchronize{cache[source]}
185       return klass
186     end
187   end
188 
189   klass = Sequel.set_temp_name(Class.new(self)){"Sequel::_Model(#{source.inspect})"}
190 
191   if source.is_a?(::Sequel::Database)
192     klass.db = source
193   else
194     klass.set_dataset(source)
195   end
196 
197   if cache_anonymous_models
198     Sequel.synchronize{cache[source] = klass}
199   end
200 
201   klass
202 end

Lets you create a Model subclass with its dataset already set. source should be an instance of one of the following classes:

Database: Sets the database for this model to source. Generally only useful when subclassing directly from the returned class, where the name of the subclass sets the table name (which is combined with the Database in source to create the dataset to use)
Dataset: Sets the dataset for this model to source.
other: Sets the table name for this model to source. The class will use the default database for model classes in order to create the dataset.

The purpose of this method is to set the dataset/database automatically for a model class, if the table name doesn’t match the default table name that Sequel would use.

When creating subclasses of Sequel::Model itself, this method is usually called on Sequel itself, using Sequel::Model(:something).

# Using a symbol
class Comment < Sequel::Model(:something)
  table_name # => :something
end

# Using a dataset
class Comment < Sequel::Model(DB1[:something])
  dataset # => DB1[:something]
end

# Using a database
class Comment < Sequel::Model(DB1)
  dataset # => DB1[:comments]
end

call (values)

Source

    # File lib/sequel/model/base.rb
223 def call(values)
224   o = allocate
225   o.instance_variable_set(:@values, values)
226   o
227 end

Initializes a model instance as an existing record. This constructor is used by Sequel to initialize model instances when fetching records. Requires that values be a hash where all keys are symbols. It probably should not be used by external code.

clear_setter_methods_cache ()

Source

    # File lib/sequel/model/base.rb
230 def clear_setter_methods_cache
231   @setter_methods = nil unless frozen?
232 end

Clear the setter_methods cache

columns ()

Source

    # File lib/sequel/model/base.rb
241 def columns
242   return @columns if @columns
243   return nil if frozen?
244   set_columns(dataset.naked.columns)
245 end

Returns the columns in the result set in their original order. Generally, this will use the columns determined via the database schema, but in certain cases (e.g. models that are based on a joined dataset) it will use Dataset#columns to find the columns.

Artist.columns
# => [:id, :name]

create (values = OPTS, &block)

Source

    # File lib/sequel/model/base.rb
255 def create(values = OPTS, &block)
256   new(values, &block).save
257 end

Creates instance using new with the given values and block, and saves it.

Artist.create(name: 'Bob')
# INSERT INTO artists (name) VALUES ('Bob')

Artist.create do |a|
  a.name = 'Jim'
end # INSERT INTO artists (name) VALUES ('Jim')

dataset ()

Source

    # File lib/sequel/model/base.rb
265 def dataset
266   @dataset || raise(Error, "No dataset associated with #{self}")
267 end

Returns the dataset associated with the Model class. Raises an Error if there is no associated dataset for this class. In most cases, you don’t need to call this directly, as Model proxies many dataset methods to the underlying dataset.

Artist.dataset.all # SELECT * FROM artists

dataset= (ds)

Source

    # File lib/sequel/model/base.rb
270 def dataset=(ds)
271   set_dataset(ds)
272 end

Alias of set_dataset

dataset_module (mod = nil, &block)

Source

    # File lib/sequel/model/base.rb
329 def dataset_module(mod = nil, &block)
330   if mod
331     raise Error, "can't provide both argument and block to Model.dataset_module" if block
332     dataset_extend(mod)
333     mod
334   else
335     @dataset_module ||= dataset_module_class.new(self)
336     @dataset_module.module_eval(&block) if block
337     dataset_extend(@dataset_module)
338     @dataset_module
339   end
340 end

Extend the dataset with a module, similar to adding a plugin with the methods defined in DatasetMethods. This is the recommended way to add methods to model datasets.

If given an argument, it should be a module, and is used to extend the underlying dataset. Otherwise an anonymous module is created, and if a block is given, it is module_evaled, allowing you do define dataset methods directly using the standard ruby def syntax. Returns the module given or the anonymous module created.

# Usage with existing module
Album.dataset_module Sequel::ColumnsIntrospection

# Usage with anonymous module
Album.dataset_module do
  def foo
    :bar
  end
end
Album.dataset.foo
# => :bar
Album.foo
# => :bar

Any anonymous modules created are actually instances of Sequel::Model::DatasetModule (a Module subclass), which allows you to call the subset method on them, which defines a dataset method that adds a filter. There are also a number of other methods with the same names as the dataset methods, which can use to define named dataset methods:

Album.dataset_module do
  where(:released, Sequel[:release_date] <= Sequel::CURRENT_DATE)
  order :by_release_date, :release_date
  select :for_select_options, :id, :name, :release_date
end
Album.released.sql
# => "SELECT * FROM artists WHERE (release_date <= CURRENT_DATE)"
Album.by_release_date.sql
# => "SELECT * FROM artists ORDER BY release_date"
Album.for_select_options.sql
# => "SELECT id, name, release_date FROM artists"
Album.released.by_release_date.for_select_options.sql
# => "SELECT id, name, release_date FROM artists WHERE (release_date <= CURRENT_DATE) ORDER BY release_date"

The following methods are supported: distinct, eager, exclude, exclude_having, grep, group, group_and_count, group_append, having, limit, offset, order, order_append, order_prepend, select, select_all, select_append, select_group, where, and server.

The advantage of using these DatasetModule methods to define your dataset methods is that they can take advantage of dataset caching to improve performance.

Any public methods in the dataset module will have class methods created that call the method on the dataset, assuming that the class method is not already defined.

db ()

Source

    # File lib/sequel/model/base.rb
352 def db
353   return @db if @db
354   @db = self == Model ? Sequel.synchronize{DATABASES.first} : superclass.db
355   raise(Error, "No database associated with #{self}: have you called Sequel.connect or #{self}.db= ?") unless @db
356   @db
357 end

Returns the database associated with the Model class. If this model doesn’t have a database associated with it, assumes the superclass’s database, or the first object in Sequel::DATABASES. If no Sequel::Database object has been created, raises an error.

Artist.db.transaction do # BEGIN
  Artist.create(name: 'Bob')
  # INSERT INTO artists (name) VALUES ('Bob')
end # COMMIT

db= (db)

Source

    # File lib/sequel/model/base.rb
373 def db=(db)
374   raise Error, "Cannot use Sequel::Model.db= on model with existing dataset.  Use Sequel::Model.dataset= instead." if @dataset
375   @db = db
376 end

Sets the database associated with the Model class. Should only be used if the Model class currently does not have a dataset defined.

This can be used directly on Sequel::Model to set the default database to be used by subclasses, or to override the database used for specific models:

Sequel::Model.db = DB1
Artist = Class.new(Sequel::Model)
Artist.db = DB2

Note that you should not use this to change the model’s database at runtime. If you have that need, you should look into Sequel’s sharding support, or consider using separate model classes per Database.

db_schema ()

Source

    # File lib/sequel/model/base.rb
386 def db_schema
387   return @db_schema if @db_schema
388   return nil if frozen?
389   @db_schema = get_db_schema
390 end

Returns the cached schema information if available or gets it from the database. This is a hash where keys are column symbols and values are hashes of information related to the column. See Database#schema.

Artist.db_schema
# {:id=>{:type=>:integer, :primary_key=>true, ...},
#  :name=>{:type=>:string, :primary_key=>false, ...}}

def_Model (mod)

Source

    # File lib/sequel/model/base.rb
139 def def_Model(mod)
140   model = self
141   mod.define_singleton_method(:Model) do |source|
142     model.Model(source)
143   end
144 end

Define a Model method on the given module that calls the Model method on the receiver. This is how the Sequel::Model() method is defined, and allows you to define Model() methods on other modules, making it easier to have custom model settings for all models under a namespace. Example:

module Foo
  Model = Class.new(Sequel::Model)
  Model.def_Model(self)
  DB = Model.db = Sequel.connect(ENV['FOO_DATABASE_URL'])
  Model.plugin :prepared_statements

  class Bar < Model
    # Uses Foo::DB[:bars]
  end

  class Baz < Model(:my_baz)
    # Uses Foo::DB[:my_baz]
  end
end

def_column_alias (meth, column)

Source

    # File lib/sequel/model/base.rb
394 def def_column_alias(meth, column)
395   clear_setter_methods_cache
396   overridable_methods_module.module_eval do
397     define_method(meth){self[column]}
398     define_method("#{meth}="){|v| self[column] = v}
399   end
400 end

Create a column alias, where the column methods have one name, but the underlying storage uses a different name.

find (*args, &block)

Source

    # File lib/sequel/model/base.rb
410 def find(*args, &block)
411   first(*args, &block)
412 end

Finds a single record according to the supplied filter. You are encouraged to use Model[] or Model.first instead of this method.

Artist.find(name: 'Bob')
# SELECT * FROM artists WHERE (name = 'Bob') LIMIT 1

Artist.find{name > 'M'}
# SELECT * FROM artists WHERE (name > 'M') LIMIT 1

find_or_create (cond, &block)

Source

    # File lib/sequel/model/base.rb
426 def find_or_create(cond, &block)
427   find(cond) || create(cond, &block)
428 end

Like find but invokes create with given conditions when record does not exist. Unlike find in that the block used in this method is not passed to find, but instead is passed to create only if find does not return an object.

Artist.find_or_create(name: 'Bob')
# SELECT * FROM artists WHERE (name = 'Bob') LIMIT 1
# INSERT INTO artists (name) VALUES ('Bob')

Artist.find_or_create(name: 'Jim'){|a| a.hometown = 'Sactown'}
# SELECT * FROM artists WHERE (name = 'Jim') LIMIT 1
# INSERT INTO artists (name, hometown) VALUES ('Jim', 'Sactown')

freeze ()

Source

    # File lib/sequel/model/base.rb
431 def freeze
432   return self if frozen?
433   dataset_module.freeze
434   overridable_methods_module.freeze
435 
436   if @dataset
437     db_schema.freeze.each_value(&:freeze)
438     columns.freeze
439     setter_methods.freeze
440   else
441     @setter_methods = [].freeze
442   end
443 
444   @dataset_method_modules.freeze
445   @default_set_fields_options.freeze
446   @plugins.freeze
447 
448   super
449 end

Freeze a model class, disallowing any further changes to it.

Calls superclass method

has_dataset? ()

Source

    # File lib/sequel/model/base.rb
454 def has_dataset?
455   !@dataset.nil?
456 end

Whether the model has a dataset. True for most model classes, but can be false if the model class is an abstract model class designed for subclassing, such as Sequel::Model itself.

implicit_table_name ()

Source

    # File lib/sequel/model/base.rb
470 def implicit_table_name
471   pluralize(underscore(demodulize(name))).to_sym
472 end

Returns the implicit table name for the model class, which is the demodulized, underscored, pluralized name of the class.

Artist.implicit_table_name # => :artists
Foo::ArtistAlias.implicit_table_name # => :artist_aliases

include (*mods)

Source

    # File lib/sequel/model/base.rb
460 def include(*mods)
461   clear_setter_methods_cache
462   super
463 end

Clear the setter_methods cache when a module is included, as it may contain setter methods.

Calls superclass method

load (values)

Source

    # File lib/sequel/model/base.rb
475 def load(values)
476   call(values)
477 end

Calls call with the values hash.

no_primary_key ()

Source

    # File lib/sequel/model/base.rb
485 def no_primary_key
486   clear_setter_methods_cache
487   self.simple_pk = @primary_key = nil
488 end

Mark the model as not having a primary key. Not having a primary key can cause issues, among which is that you won’t be able to update records.

Artist.primary_key # => :id
Artist.no_primary_key
Artist.primary_key # => nil

plugin (plugin, *args, &block)

Source

    # File lib/sequel/model/base.rb
494 def plugin(plugin, *args, &block)
495   m = plugin.is_a?(Module) ? plugin : plugin_module(plugin)
496 
497   if !m.respond_to?(:apply) && !m.respond_to?(:configure) && (!args.empty? || block)
498     Deprecation.deprecate("Plugin #{plugin} accepts no arguments or block, and passing arguments/block to it", "Remove arguments and block when loading the plugin")
499   end
500 
501   unless @plugins.include?(m)
502     @plugins << m
503     m.apply(self, *args, &block) if m.respond_to?(:apply)
504     extend(m::ClassMethods) if m.const_defined?(:ClassMethods, false)
505     include(m::InstanceMethods) if m.const_defined?(:InstanceMethods, false)
506     if m.const_defined?(:DatasetMethods, false)
507       dataset_extend(m::DatasetMethods, :create_class_methods=>false)
508     end
509   end
510 
511   m.configure(self, *args, &block) if m.respond_to?(:configure)
512 end

Loads a plugin for use with the model class, passing optional arguments to the plugin. If the plugin is a module, load it directly. Otherwise, require the plugin from sequel/plugins/#{plugin} and then attempt to load the module using a the camelized plugin name under Sequel::Plugins.

primary_key_hash (value)

Source

    # File lib/sequel/model/base.rb
525 def primary_key_hash(value)
526   case key = @primary_key
527   when Symbol
528     {key => value}
529   when Array
530     hash = {}
531     key.zip(Array(value)){|k,v| hash[k] = v}
532     hash
533   else
534     raise(Error, "#{self} does not have a primary key")
535   end
536 end

Returns primary key attribute hash. If using a composite primary key value such be an array with values for each primary key in the correct order. For a standard primary key, value should be an object with a compatible type for the key. If the model does not have a primary key, raises an Error.

Artist.primary_key_hash(1) # => {:id=>1}
Artist.primary_key_hash([1, 2]) # => {:id1=>1, :id2=>2}

qualified_primary_key (qualifier=table_name)

Source

    # File lib/sequel/model/base.rb
545 def qualified_primary_key(qualifier=table_name)
546   case key = @primary_key
547   when Symbol
548     SQL::QualifiedIdentifier.new(qualifier, key)
549   when Array
550     key.map{|k| SQL::QualifiedIdentifier.new(qualifier, k)}
551   else
552     raise(Error, "#{self} does not have a primary key")
553   end
554 end

Return a qualified identifier or array of qualified identifiers for the model’s primary key. Uses the given qualifier if provided, or the table_name otherwise. If the model does not have a primary key, raises an Error.

Artist.order(Artist.qualified_primary_key)
# SELECT * FROM artists ORDER BY artists.id

qualified_primary_key_hash (value, qualifier=table_name)

Source

    # File lib/sequel/model/base.rb
563 def qualified_primary_key_hash(value, qualifier=table_name)
564   case key = @primary_key
565   when Symbol
566     {SQL::QualifiedIdentifier.new(qualifier, key) => value}
567   when Array
568     hash = {}
569     key.zip(Array(value)){|k,v| hash[SQL::QualifiedIdentifier.new(qualifier, k)] = v}
570     hash
571   else
572     raise(Error, "#{self} does not have a primary key")
573   end
574 end

Return a hash where the keys are qualified column references. Uses the given qualifier if provided, or the table_name otherwise. This is useful if you plan to join other tables to this table and you want the column references to be qualified. If the model does not have a primary key, raises an Error.

Artist.where(Artist.qualified_primary_key_hash(1))
# SELECT * FROM artists WHERE (artists.id = 1)

restrict_primary_key ()

Source

    # File lib/sequel/model/base.rb
579 def restrict_primary_key
580   clear_setter_methods_cache
581   @restrict_primary_key = true
582 end

Restrict the setting of the primary key(s) when using mass assignment (e.g. set). Because this is the default, this only make sense to use in a subclass where the parent class has used unrestrict_primary_key.

restrict_primary_key? ()

Source

    # File lib/sequel/model/base.rb
586 def restrict_primary_key?
587   @restrict_primary_key
588 end

Whether or not setting the primary key(s) when using mass assignment (e.g. set) is restricted, true by default.

set_dataset (ds, opts=OPTS)

Source

    # File lib/sequel/model/base.rb
616 def set_dataset(ds, opts=OPTS)
617   inherited = opts[:inherited]
618   @dataset = convert_input_dataset(ds)
619   @require_modification = @dataset.provides_accurate_rows_matched? if require_modification.nil?
620   if inherited
621     self.simple_table = superclass.simple_table
622     @columns = superclass.instance_variable_get(:@columns)
623     @db_schema = superclass.instance_variable_get(:@db_schema)
624   else
625     @dataset = @dataset.with_extend(*@dataset_method_modules.reverse)
626     @db_schema = get_db_schema
627   end
628 
629   @fast_pk_lookup_sql = @fast_instance_delete_sql = nil unless @dataset.supports_placeholder_literalizer?
630   reset_instance_dataset
631   self
632 end

Sets the dataset associated with the Model class. ds can be a Symbol, LiteralString, SQL::Identifier, SQL::QualifiedIdentifier, SQL::AliasedExpression (all specifying a table name in the current database), or a Dataset. If a dataset is used, the model’s database is changed to the database of the given dataset. If a dataset is not used, a dataset is created from the current database with the table name given. Other arguments raise an Error. Returns self.

It also attempts to determine the database schema for the model, based on the given dataset.

Note that you should not use this to change the model’s dataset at runtime. If you have that need, you should look into Sequel’s sharding support, or creating a separate Model class per dataset

You should avoid calling this method directly if possible. Instead you should set the table name or dataset when creating the model class:

# table name
class Artist < Sequel::Model(:tbl_artists)
end

# dataset
class Artist < Sequel::Model(DB[:tbl_artists])
end

set_primary_key (key)

Source

    # File lib/sequel/model/base.rb
648 def set_primary_key(key)
649   clear_setter_methods_cache
650   if key.is_a?(Array)
651     if key.length < 2
652       key = key.first
653     else
654       key = key.dup.freeze
655     end
656   end
657   self.simple_pk = if key && !key.is_a?(Array)
658     (@dataset || db).literal(key).freeze
659   end
660   @primary_key = key
661 end

Sets the primary key for this model. You can use either a regular or a composite primary key. To not use a primary key, set to nil or use no_primary_key. On most adapters, Sequel can automatically determine the primary key to use, so this method is not needed often.

class Person < Sequel::Model
  # regular key
  set_primary_key :person_id
end

class Tagging < Sequel::Model
  # composite key
  set_primary_key [:taggable_id, :tag_id]
end

setter_methods ()

Source

    # File lib/sequel/model/base.rb
664 def setter_methods
665   @setter_methods || (@setter_methods = get_setter_methods)
666 end

Cache of setter methods to allow by default, in order to speed up mass assignment.

table_name ()

Source

    # File lib/sequel/model/base.rb
674 def table_name
675   dataset.first_source_alias
676 end

Returns name of primary table for the dataset. If the table for the dataset is aliased, returns the aliased name.

Artist.table_name # => :artists
Sequel::Model(:foo).table_name # => :foo
Sequel::Model(Sequel[:foo].as(:bar)).table_name # => :bar

unrestrict_primary_key ()

Source

    # File lib/sequel/model/base.rb
684 def unrestrict_primary_key
685   clear_setter_methods_cache
686   @restrict_primary_key = false
687 end

Allow the setting of the primary key(s) when using the mass assignment methods. Using this method can open up security issues, be very careful before using it.

Artist.set(id: 1) # Error
Artist.unrestrict_primary_key
Artist.set(id: 1) # No Error

with_pk (pk)

Source

    # File lib/sequel/model/base.rb
690 def with_pk(pk)
691   primary_key_lookup(pk)
692 end

Return the model instance with the primary key, or nil if there is no matching record.

with_pk! (pk)

Source

    # File lib/sequel/model/base.rb
695 def with_pk!(pk)
696   with_pk(pk) || raise(NoMatchingRow.new(dataset))
697 end

Return the model instance with the primary key, or raise NoMatchingRow if there is no matching record.

Private Instance Methods

check_non_connection_error (do_raise=require_valid_table) { || ... }

Source

    # File lib/sequel/model/base.rb
706 def check_non_connection_error(do_raise=require_valid_table)
707   db.transaction(:savepoint=>:only){yield}
708 rescue Sequel::DatabaseConnectionError, Sequel::DatabaseDisconnectError
709   raise
710 rescue Sequel::Error
711   raise if do_raise
712 end

Yield to the passed block and if do_raise is false, swallow Sequel::Errors other than DatabaseConnectionError and DatabaseDisconnectError.

convert_input_dataset (ds)

Source

    # File lib/sequel/model/base.rb
716 def convert_input_dataset(ds)
717   case ds
718   when Symbol, SQL::Identifier, SQL::QualifiedIdentifier
719     self.simple_table = db.literal(ds).freeze
720     ds = db.from(ds)
721   when SQL::AliasedExpression, LiteralString
722     self.simple_table = nil
723     ds = db.from(ds)
724   when Dataset
725     ds = ds.from_self(:alias=>ds.first_source) if ds.joined_dataset?
726 
727     self.simple_table = if ds.send(:simple_select_all?)
728       ds.literal(ds.first_source_table).freeze
729     end
730     @db = ds.db
731   else
732     raise(Error, "Model.set_dataset takes one of the following classes as an argument: Symbol, LiteralString, SQL::Identifier, SQL::QualifiedIdentifier, SQL::AliasedExpression, Dataset")
733   end
734 
735   set_dataset_row_proc(ds.clone(:model=>self))
736 end

Convert the given object to a Dataset that should be used as this model’s dataset.

dataset_extend (mod, opts=OPTS)

Source

    # File lib/sequel/model/base.rb
741 def dataset_extend(mod, opts=OPTS)
742   @dataset = @dataset.with_extend(mod) if @dataset
743   reset_instance_dataset
744   dataset_method_modules << mod
745   unless opts[:create_class_methods] == false
746     mod.public_instance_methods.each{|meth| def_model_dataset_method(meth)}
747   end
748 end

Add the module to the class’s dataset_method_modules. Extend the dataset with the module if the model has a dataset. Add dataset methods to the class for all public dataset methods.

dataset_methods_module ()

Source

    # File lib/sequel/model/base.rb
789 def dataset_methods_module
790   return @dataset_methods_module if defined?(@dataset_methods_module)
791   mod_name = "#{name}::@dataset_methods_module"
792   Sequel.synchronize{@dataset_methods_module ||= Sequel.set_temp_name(Module.new){mod_name}}
793   extend(@dataset_methods_module)
794   @dataset_methods_module
795 end

Module that the class methods that call dataset methods are kept in. This allows the methods to be overridden and call super with the default behavior.

def_bad_column_accessor (column)

Source

    # File lib/sequel/model/base.rb
751 def def_bad_column_accessor(column)
752   im = instance_methods
753   overridable_methods_module.module_eval do
754     meth = :"#{column}="
755     unless im.include?(column)
756       define_method(column){self[column]}
757       alias_method(column, column)
758     end
759     unless im.include?(meth)
760       define_method(meth){|v| self[column] = v}
761       alias_method(meth, meth)
762     end
763   end
764 end

Create a column accessor for a column with a method name that is hard to use in ruby code.

def_column_accessor (*columns)

Source

    # File lib/sequel/model/base.rb
768 def def_column_accessor(*columns)
769   clear_setter_methods_cache
770   columns, bad_columns = columns.partition{|x| /\A[A-Za-z_][A-Za-z0-9_]*\z/.match(x.to_s)}
771   bad_columns.each{|x| def_bad_column_accessor(x)}
772   im = instance_methods
773   columns.each do |column|
774     meth = :"#{column}="
775     unless im.include?(column)
776       overridable_methods_module.module_eval("def #{column}; self[:#{column}] end", __FILE__, __LINE__)
777       overridable_methods_module.send(:alias_method, column, column)
778     end
779     unless im.include?(meth)
780       overridable_methods_module.module_eval("def #{meth}(v); self[:#{column}] = v end", __FILE__, __LINE__)
781       overridable_methods_module.send(:alias_method, meth, meth)
782     end
783   end
784 end

Create the column accessors. For columns that can be used as method names directly in ruby code, use a string to define the method for speed. For other columns names, use a block.

def_model_dataset_method (meth)

Source

    # File lib/sequel/model/base.rb
798       def def_model_dataset_method(meth)
799         return if respond_to?(meth, true)
800 
801         mod = dataset_methods_module
802 
803         if meth.to_s =~ /\A[A-Za-z_][A-Za-z0-9_]*\z/
804           mod.module_eval(<<END, __FILE__, __LINE__ + 1)
805 def #{meth}(*args, &block); dataset.#{meth}(*args, &block) end
806 ruby2_keywords :#{meth} if respond_to?(:ruby2_keywords, true)
807 END
808         else
809           mod.send(:define_method, meth){|*args, &block| dataset.public_send(meth, *args, &block)}
810           # :nocov:
811           mod.send(:ruby2_keywords, meth) if respond_to?(:ruby2_keywords, true)
812           # :nocov:
813         end
814         mod.send(:alias_method, meth, meth)
815       end

Define a model method that calls the dataset method with the same name.

get_db_schema (reload = reload_db_schema?)

Source

    # File lib/sequel/model/base.rb
820 def get_db_schema(reload = reload_db_schema?)
821   set_columns(nil)
822   return nil unless @dataset
823   schema_hash = {}
824   ds_opts = dataset.opts
825   get_columns = proc{check_non_connection_error{columns} || []}
826   schema_array = get_db_schema_array(reload) if db.supports_schema_parsing?
827   if schema_array
828     schema_array.each{|k,v| schema_hash[k] = v}
829 
830     # Set the primary key(s) based on the schema information,
831     # if the schema information includes primary key information
832     if schema_array.all?{|k,v| v.has_key?(:primary_key)}
833       pks = schema_array.map{|k,v| k if v[:primary_key]}.compact
834       pks.length > 0 ? set_primary_key(pks) : no_primary_key
835     end
836 
837     if (select = ds_opts[:select]) && !(select.length == 1 && select.first.is_a?(SQL::ColumnAll))
838       # We don't remove the columns from the schema_hash,
839       # as it's possible they will be used for typecasting
840       # even if they are not selected.
841       cols = get_columns.call
842       cols.each{|c| schema_hash[c] ||= {}}
843       def_column_accessor(*schema_hash.keys)
844     else
845       # Dataset is for a single table with all columns,
846       # so set the columns based on the order they were
847       # returned by the schema.
848       cols = schema_array.map{|k,v| k}
849       set_columns(cols)
850       # Also set the columns for the dataset, so the dataset
851       # doesn't have to do a query to get them.
852       dataset.send(:columns=, cols)
853     end
854   else
855     # If the dataset uses multiple tables or custom sql or getting
856     # the schema raised an error, just get the columns and
857     # create an empty schema hash for it.
858     get_columns.call.each{|c| schema_hash[c] = {}}
859   end
860   schema_hash
861 end

Get the schema from the database, fall back on checking the columns via the database if that will return inaccurate results or if it raises an error.

get_db_schema_array (reload)

Source

    # File lib/sequel/model/base.rb
865 def get_db_schema_array(reload)
866   check_non_connection_error(false){db.schema(dataset, :reload=>reload)}
867 end

Get the array of schema information for the dataset. Returns nil if the schema information cannot be determined.

get_setter_methods ()

Source

    # File lib/sequel/model/base.rb
871 def get_setter_methods
872   meths = instance_methods.map(&:to_s).select{|l| l.end_with?('=')} - RESTRICTED_SETTER_METHODS
873   meths -= Array(primary_key).map{|x| "#{x}="} if primary_key && restrict_primary_key?
874   meths
875 end

Uncached version of setter_methods, to be overridden by plugins that want to modify the methods used.

inherited (subclass)

Source

    # File lib/sequel/model/base.rb
886 def inherited(subclass)
887   super
888   ivs = subclass.instance_variables
889   inherited_instance_variables.each do |iv, dup|
890     if (sup_class_value = instance_variable_get(iv)) && dup
891       sup_class_value = case dup
892       when :dup
893         sup_class_value.dup
894       when :hash_dup
895         h = {}
896         sup_class_value.each{|k,v| h[k] = v.dup}
897         h
898       when Proc
899         dup.call(sup_class_value)
900       else
901         raise Error, "bad inherited instance variable type: #{dup.inspect}"
902       end
903     end
904     subclass.instance_variable_set(iv, sup_class_value)
905   end
906 
907   unless ivs.include?(:@dataset)
908     if @dataset && self != Model
909       subclass.set_dataset(@dataset.clone, :inherited=>true)
910     elsif (n = subclass.name) && !n.to_s.empty?
911       db
912       subclass.set_dataset(subclass.implicit_table_name)
913     end
914   end
915 end

If possible, set the dataset for the model subclass as soon as it is created. Also, make sure the inherited class instance variables are copied into the subclass.

Sequel queries the database to get schema information as soon as a model class is created:

class Artist < Sequel::Model # Causes schema query
end

Calls superclass method

inherited_instance_variables ()

Source

    # File lib/sequel/model/base.rb
923 def inherited_instance_variables
924   {
925     :@cache_anonymous_models=>nil,
926     :@dataset_method_modules=>:dup,
927     :@dataset_module_class=>nil,
928     :@db=>nil,
929     :@default_set_fields_options=>:dup,
930     :@fast_instance_delete_sql=>nil,
931     :@fast_pk_lookup_sql=>nil,
932     :@plugins=>:dup,
933     :@primary_key=>nil,
934     :@raise_on_save_failure=>nil,
935     :@raise_on_typecast_failure=>nil,
936     :@require_modification=>nil,
937     :@require_valid_table=>nil,
938     :@restrict_primary_key=>nil,
939     :@setter_methods=>nil,
940     :@simple_pk=>nil,
941     :@simple_table=>nil,
942     :@strict_param_setting=>nil,
943     :@typecast_empty_string_to_nil=>nil,
944     :@typecast_on_assignment=>nil,
945     :@use_transactions=>nil
946   }
947 end

A hash of instance variables to automatically set up in subclasses. Keys are instance variable symbols, values should be:

nil: Assign directly from superclass to subclass (frozen objects)
:dup: Dup object when assigning from superclass to subclass (mutable objects)
:hash_dup: Assign hash with same keys, but dup all the values
Proc: Call with subclass to do the assignment

late_binding_class_option (opts, default)

Source

    # File lib/sequel/model/base.rb
953 def late_binding_class_option(opts, default)
954   case opts[:class]
955     when String, Symbol
956       # Delete :class to allow late binding
957       class_name = opts.delete(:class).to_s
958 
959       if (namespace = opts[:class_namespace]) && !class_name.start_with?('::')
960         class_name = "::#{namespace}::#{class_name}"
961       end
962 
963       opts[:class_name] ||= class_name
964     when Class
965       opts[:class_name] ||= opts[:class].name
966   end
967 
968   opts[:class_name] ||= '::' + ((name || '').split("::")[0..-2] + [camelize(default)]).join('::')
969 end

For the given opts hash and default name or :class option, add a :class_name option unless already present which contains the name of the class to use as a string. The purpose is to allow late binding to the class later using constantize.

method_added (meth)

Source

    # File lib/sequel/model/base.rb
972 def method_added(meth)
973   clear_setter_methods_cache if meth.to_s.end_with?('=')
974   super
975 end

Clear the setter_methods cache when a setter method is added.

Calls superclass method

overridable_methods_module ()

Source

    # File lib/sequel/model/base.rb
979 def overridable_methods_module
980   return @overridable_methods_module if defined?(@overridable_methods_module)
981   mod_name = "#{name}::@overridable_methods_module"
982   Sequel.synchronize{@overridable_methods_module ||= Sequel.set_temp_name(Module.new){mod_name}}
983   include(@overridable_methods_module)
984   @overridable_methods_module
985 end

Module that the class includes that holds methods the class adds for column accessors and associations so that the methods can be overridden with super.

plugin_module (plugin)

Source

    # File lib/sequel/model/base.rb
989 def plugin_module(plugin)
990   module_name = plugin.to_s.gsub(/(^|_)(.)/){|x| x[-1..-1].upcase}
991   unless Sequel::Plugins.const_defined?(module_name, false)
992     require "sequel/plugins/#{plugin}"
993   end
994   Sequel::Plugins.const_get(module_name)
995 end

Returns the module for the specified plugin. If the module is not defined, the corresponding plugin required.

primary_key_lookup (pk)

Source

     # File lib/sequel/model/base.rb
1003 def primary_key_lookup(pk)
1004   if sql = @fast_pk_lookup_sql
1005     sql = sql.dup
1006     ds = dataset
1007     ds.literal_append(sql, pk)
1008     ds.fetch_rows(sql){|r| return ds.row_proc.call(r)}
1009     nil
1010   else
1011     dataset.first(primary_key_hash(pk))
1012   end
1013 end

Find the row in the dataset that matches the primary key. Uses a static SQL optimization if the table and primary key are simple.

This method should not be called with a nil primary key, in case it is overridden by plugins which assume that the passed argument is valid.

reload_db_schema? ()

Source

     # File lib/sequel/model/base.rb
1016 def reload_db_schema?
1017   false
1018 end

Whether to reload the database schema by default, ignoring any cached value.

reset_fast_pk_lookup_sql ()

Source

     # File lib/sequel/model/base.rb
1022 def reset_fast_pk_lookup_sql
1023   @fast_pk_lookup_sql = if @simple_table && @simple_pk
1024     "SELECT * FROM #{@simple_table} WHERE #{@simple_pk} = ".freeze
1025   end
1026   @fast_instance_delete_sql = if @simple_table && @simple_pk
1027     "DELETE FROM #{@simple_table} WHERE #{@simple_pk} = ".freeze
1028   end
1029 end

Reset the cached fast primary lookup SQL if a simple table and primary key are used, or set it to nil if not used.

reset_instance_dataset ()

Source

     # File lib/sequel/model/base.rb
1033 def reset_instance_dataset
1034   @instance_dataset = @dataset.limit(1).naked.skip_limit_check if @dataset
1035 end

Reset the instance dataset to a modified copy of the current dataset, should be used whenever the model’s dataset is modified.

set_columns (new_columns)

Source

     # File lib/sequel/model/base.rb
1038 def set_columns(new_columns)
1039   @columns = new_columns
1040   def_column_accessor(*new_columns) if new_columns
1041   @columns
1042 end

Set the columns for this model and create accessor methods for each column.

set_dataset_row_proc (ds)

Source

     # File lib/sequel/model/base.rb
1045 def set_dataset_row_proc(ds)
1046   ds.with_row_proc(self)
1047 end

Set the dataset’s row_proc to the current model.

simple_pk= (pk)

Source

     # File lib/sequel/model/base.rb
1050 def simple_pk=(pk)
1051   @simple_pk = pk
1052   reset_fast_pk_lookup_sql
1053 end

Reset the fast primary key lookup SQL when the simple_pk value changes.

simple_table= (t)

Source

     # File lib/sequel/model/base.rb
1056 def simple_table=(t)
1057   @simple_table = t
1058   reset_fast_pk_lookup_sql
1059 end

Reset the fast primary key lookup SQL when the simple_table value changes.