Module | Sequel::Model::ClassMethods |
In: |
lib/sequel/model/base.rb
|
Class methods for Sequel::Model that implement basic model functionality.
cache_anonymous_models | [RW] | 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. |
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
# File lib/sequel/model/base.rb, line 179 179: def Model(source) 180: if cache_anonymous_models 181: cache = Sequel.synchronize{@Model_cache ||= {}} 182: if klass = Sequel.synchronize{cache[source]} 183: return klass 184: end 185: end 186: 187: klass = Class.new(self) 188: 189: if source.is_a?(::Sequel::Database) 190: klass.db = source 191: else 192: klass.set_dataset(source) 193: end 194: 195: if cache_anonymous_models 196: Sequel.synchronize{cache[source] = klass} 197: end 198: 199: klass 200: 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', ...}>
# File lib/sequel/model/base.rb, line 212 212: def [](*args) 213: args = args.first if args.size <= 1 214: args.is_a?(Hash) ? first(args) : (primary_key_lookup(args) unless args.nil?) 215: 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.
# File lib/sequel/model/base.rb, line 221 221: def call(values) 222: o = allocate 223: o.instance_variable_set(:@values, values) 224: o 225: end
Clear the setter_methods cache
# File lib/sequel/model/base.rb, line 228 228: def clear_setter_methods_cache 229: @setter_methods = nil unless frozen? 230: 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]
# File lib/sequel/model/base.rb, line 239 239: def columns 240: return @columns if @columns 241: return nil if frozen? 242: set_columns(dataset.naked.columns) 243: 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')
# File lib/sequel/model/base.rb, line 253 253: def create(values = {}, &block) 254: new(values, &block).save 255: 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
# File lib/sequel/model/base.rb, line 263 263: def dataset 264: @dataset || raise(Error, "No dataset associated with #{self}") 265: end
Alias of set_dataset
# File lib/sequel/model/base.rb, line 268 268: def dataset=(ds) 269: set_dataset(ds) 270: 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.
# File lib/sequel/model/base.rb, line 327 327: def dataset_module(mod = nil) 328: if mod 329: raise Error, "can't provide both argument and block to Model.dataset_module" if block_given? 330: dataset_extend(mod) 331: mod 332: else 333: @dataset_module ||= dataset_module_class.new(self) 334: @dataset_module.module_eval(&Proc.new) if block_given? 335: dataset_extend(@dataset_module) 336: @dataset_module 337: end 338: 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
# File lib/sequel/model/base.rb, line 350 350: def db 351: return @db if @db 352: @db = self == Model ? Sequel.synchronize{DATABASES.first} : superclass.db 353: raise(Error, "No database associated with #{self}: have you called Sequel.connect or #{self}.db= ?") unless @db 354: @db 355: 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.
# File lib/sequel/model/base.rb, line 371 371: def db=(db) 372: raise Error, "Cannot use Sequel::Model.db= on model with existing dataset. Use Sequel::Model.dataset= instead." if @dataset 373: @db = db 374: 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, ...}}
# File lib/sequel/model/base.rb, line 384 384: def db_schema 385: return @db_schema if @db_schema 386: return nil if frozen? 387: @db_schema = get_db_schema 388: 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
# File lib/sequel/model/base.rb, line 137 137: def def_Model(mod) 138: model = self 139: mod.define_singleton_method(:Model) do |source| 140: model.Model(source) 141: end 142: end
Create a column alias, where the column methods have one name, but the underlying storage uses a different name.
# File lib/sequel/model/base.rb, line 392 392: def def_column_alias(meth, column) 393: clear_setter_methods_cache 394: overridable_methods_module.module_eval do 395: define_method(meth){self[column]} 396: define_method("#{meth}="){|v| self[column] = v} 397: end 398: 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
# File lib/sequel/model/base.rb, line 408 408: def find(*args, &block) 409: first(*args, &block) 410: 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')
# File lib/sequel/model/base.rb, line 424 424: def find_or_create(cond, &block) 425: find(cond) || create(cond, &block) 426: end
Freeze a model class, disallowing any further changes to it.
# File lib/sequel/model/base.rb, line 429 429: def freeze 430: return self if frozen? 431: dataset_module.freeze 432: overridable_methods_module.freeze 433: 434: if @dataset 435: db_schema.freeze.each_value(&:freeze) 436: columns.freeze 437: setter_methods.freeze 438: else 439: @setter_methods = [].freeze 440: end 441: 442: @dataset_method_modules.freeze 443: @default_set_fields_options.freeze 444: @plugins.freeze 445: 446: super 447: 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
# File lib/sequel/model/base.rb, line 502 502: def implicit_table_name 503: pluralize(underscore(demodulize(name))).to_sym 504: end
Clear the setter_methods cache when a module is included, as it may contain setter methods.
# File lib/sequel/model/base.rb, line 451 451: def include(*mods) 452: clear_setter_methods_cache 453: super 454: 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
# File lib/sequel/model/base.rb, line 465 465: def inherited(subclass) 466: super 467: ivs = subclass.instance_variables 468: inherited_instance_variables.each do |iv, dup| 469: next if ivs.include?(iv) 470: if (sup_class_value = instance_variable_get(iv)) && dup 471: sup_class_value = case dup 472: when :dup 473: sup_class_value.dup 474: when :hash_dup 475: h = {} 476: sup_class_value.each{|k,v| h[k] = v.dup} 477: h 478: when Proc 479: dup.call(sup_class_value) 480: else 481: raise Error, "bad inherited instance variable type: #{dup.inspect}" 482: end 483: end 484: subclass.instance_variable_set(iv, sup_class_value) 485: end 486: 487: unless ivs.include?("@dataset") 488: if @dataset && self != Model 489: subclass.set_dataset(@dataset.clone, :inherited=>true) 490: elsif (n = subclass.name) && !n.to_s.empty? 491: db 492: subclass.set_dataset(subclass.implicit_table_name) 493: end 494: end 495: end
Clear the setter_methods cache when a setter method is added.
# File lib/sequel/model/base.rb, line 512 512: def method_added(meth) 513: clear_setter_methods_cache if meth.to_s.end_with?('=') 514: super 515: 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
# File lib/sequel/model/base.rb, line 523 523: def no_primary_key 524: clear_setter_methods_cache 525: self.simple_pk = @primary_key = nil 526: 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.
# File lib/sequel/model/base.rb, line 532 532: def plugin(plugin, *args, &block) 533: m = plugin.is_a?(Module) ? plugin : plugin_module(plugin) 534: unless @plugins.include?(m) 535: @plugins << m 536: m.apply(self, *args, &block) if m.respond_to?(:apply) 537: extend(m::ClassMethods) if m.const_defined?(:ClassMethods, false) 538: include(m::InstanceMethods) if m.const_defined?(:InstanceMethods, false) 539: if m.const_defined?(:DatasetMethods, false) 540: dataset_extend(m::DatasetMethods, :create_class_methods=>false) 541: end 542: end 543: m.configure(self, *args, &block) if m.respond_to?(:configure) 544: 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}
# File lib/sequel/model/base.rb, line 554 554: def primary_key_hash(value) 555: case key = @primary_key 556: when Symbol 557: {key => value} 558: when Array 559: hash = {} 560: key.zip(Array(value)){|k,v| hash[k] = v} 561: hash 562: else 563: raise(Error, "#{self} does not have a primary key") 564: end 565: 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.
Artist.where(Artist.qualified_primary_key_hash(1)) # SELECT * FROM artists WHERE (artists.id = 1)
# File lib/sequel/model/base.rb, line 574 574: def qualified_primary_key_hash(value, qualifier=table_name) 575: case key = @primary_key 576: when Symbol 577: {SQL::QualifiedIdentifier.new(qualifier, key) => value} 578: when Array 579: hash = {} 580: key.zip(Array(value)){|k,v| hash[SQL::QualifiedIdentifier.new(qualifier, k)] = v} 581: hash 582: else 583: raise(Error, "#{self} does not have a primary key") 584: end 585: 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.
# File lib/sequel/model/base.rb, line 590 590: def restrict_primary_key 591: clear_setter_methods_cache 592: @restrict_primary_key = true 593: end
Whether or not setting the primary key(s) when using mass assignment (e.g. set) is restricted, true by default.
# File lib/sequel/model/base.rb, line 597 597: def restrict_primary_key? 598: @restrict_primary_key 599: 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
# File lib/sequel/model/base.rb, line 627 627: def set_dataset(ds, opts=OPTS) 628: inherited = opts[:inherited] 629: @dataset = convert_input_dataset(ds) 630: @require_modification = @dataset.provides_accurate_rows_matched? if require_modification.nil? 631: if inherited 632: self.simple_table = superclass.simple_table 633: @columns = superclass.instance_variable_get(:@columns) 634: @db_schema = superclass.instance_variable_get(:@db_schema) 635: else 636: @dataset = @dataset.with_extend(*@dataset_method_modules.reverse) if @dataset_method_modules 637: @db_schema = get_db_schema 638: end 639: 640: reset_instance_dataset 641: self 642: 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
# File lib/sequel/model/base.rb, line 658 658: def set_primary_key(key) 659: clear_setter_methods_cache 660: if key.is_a?(Array) 661: if key.length < 2 662: key = key.first 663: else 664: key = key.dup.freeze 665: end 666: end 667: self.simple_pk = if key && !key.is_a?(Array) 668: (@dataset || db).literal(key).freeze 669: end 670: @primary_key = key 671: end
Cache of setter methods to allow by default, in order to speed up mass assignment.
# File lib/sequel/model/base.rb, line 674 674: def setter_methods 675: return @setter_methods if @setter_methods 676: @setter_methods = get_setter_methods 677: 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
# File lib/sequel/model/base.rb, line 685 685: def table_name 686: dataset.first_source_alias 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
# File lib/sequel/model/base.rb, line 695 695: def unrestrict_primary_key 696: clear_setter_methods_cache 697: @restrict_primary_key = false 698: end
Return the model instance with the primary key, or nil if there is no matching record.
# File lib/sequel/model/base.rb, line 701 701: def with_pk(pk) 702: primary_key_lookup(pk) 703: end
Return the model instance with the primary key, or raise NoMatchingRow if there is no matching record.
# File lib/sequel/model/base.rb, line 706 706: def with_pk!(pk) 707: with_pk(pk) || raise(NoMatchingRow.new(dataset)) 708: end