Module | Sequel::Model::ClassMethods |
In: |
lib/sequel/model/base.rb
|
Class methods for Sequel::Model that implement basic model functionality.
allowed_columns | [R] | Which columns should be the only columns allowed in a call to a mass assignment method (e.g. set) (default: not set, so all columns not otherwise restricted are allowed). |
cache_anonymous_models | [RW] | Whether to cache the anonymous models created by Sequel::Model(). This is required for reloading them correctly (avoiding the superclass mismatch). True by default for backwards compatibility. |
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_methods | [R] | Hash of dataset methods with method name keys and proc values that are stored so when the dataset changes, methods defined with def_dataset_method will be applied to the new dataset. |
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. |
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/etc due to a validation failure or a before_* hook returning false. |
raise_on_typecast_failure | [RW] | Whether to raise an error when unable to typecast data for a column (default: true). This should be set to false if you want to use validations to display nice error messages to the user (e.g. most web applications). You can use the validates_not_string validations (from either the validation_helpers or validation_class_methods standard plugins) in connection with option to check for typecast failures for columns that aren‘t blobs or strings. |
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). |
restricted_columns | [R] | Which columns are specifically restricted in a call to set/update/new/etc. (default: not set). Some columns are restricted regardless of this setting, such as the primary key column and columns in Model::RESTRICTED_SETTER_METHODS. |
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 new/set/update and their variants 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_after_commit_rollback | [RW] | Whether to enable the after_commit and after_rollback hooks when saving/destroying instances. On by default, can be turned off for performance reasons or when using prepared transactions (which aren‘t compatible with after commit/rollback). |
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. |
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 122 122: def [](*args) 123: args = args.first if args.size <= 1 124: args.is_a?(Hash) ? dataset[args] : (primary_key_lookup(args) unless args.nil?) 125: 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 131 131: def call(values) 132: o = allocate 133: o.set_values(values) 134: o.after_initialize 135: o 136: end
Clear the setter_methods cache
# File lib/sequel/model/base.rb, line 139 139: def clear_setter_methods_cache 140: @setter_methods = nil 141: 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 150 150: def columns 151: @columns || set_columns(dataset.naked.columns) 152: 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 162 162: def create(values = {}, &block) 163: new(values, &block).save 164: 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 172 172: def dataset 173: @dataset || raise(Error, "No dataset associated with #{self}") 174: end
Alias of set_dataset
# File lib/sequel/model/base.rb, line 177 177: def dataset=(ds) 178: set_dataset(ds) 179: end
Extend the dataset with a module, similar to adding a plugin with the methods defined in DatasetMethods. If a block is given, an anonymous module is created and the module_evaled, otherwise the argument should be a module. Returns the module given or the anonymous module created.
Artist.dataset_module Sequel::ColumnsIntrospection Artist.dataset_module do def foo :bar end end Artist.dataset.foo # => :bar Artist.foo # => :bar
# File lib/sequel/model/base.rb, line 198 198: def dataset_module(mod = nil) 199: if mod 200: raise Error, "can't provide both argument and block to Model.dataset_module" if block_given? 201: dataset_extend(mod) 202: mod 203: else 204: @dataset_module ||= Module.new 205: @dataset_module.module_eval(&Proc.new) if block_given? 206: dataset_extend(@dataset_module) 207: @dataset_module 208: end 209: 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 221 221: def db 222: return @db if @db 223: @db = self == Model ? Sequel.synchronize{DATABASES.first} : superclass.db 224: raise(Error, "No database associated with #{self}: have you called Sequel.connect or #{self}.db= ?") unless @db 225: @db 226: end
Sets the database associated with the Model class. If the model has an associated dataset, sets the model‘s dataset to a dataset on the new database with the same options used by the current dataset. 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.db = DB2
# File lib/sequel/model/base.rb, line 238 238: def db=(db) 239: @db = db 240: set_dataset(db.dataset(@dataset.opts)) if @dataset 241: 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 251 251: def db_schema 252: @db_schema ||= get_db_schema 253: 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 257 257: def def_column_alias(meth, column) 258: clear_setter_methods_cache 259: overridable_methods_module.module_eval do 260: define_method(meth){self[column]} 261: define_method("#{meth}="){|v| self[column] = v} 262: end 263: end
If a block is given, define a method on the dataset (if the model currently has an dataset) with the given argument name using the given block. Also define a class method on the model that calls the dataset method. Stores the method name and block so that it can be reapplied if the model‘s dataset changes.
If a block is not given, just define a class method on the model for each argument that calls the dataset method of the same argument name.
# Add new dataset method and class method that calls it Artist.def_dataset_method(:by_name){order(:name)} Artist.filter(:name.like('A%')).by_name Artist.by_name.filter(:name.like('A%')) # Just add a class method that calls an existing dataset method Artist.def_dataset_method(:server!) Artist.server!(:server1)
# File lib/sequel/model/base.rb, line 281 281: def def_dataset_method(*args, &block) 282: raise(Error, "No arguments given") if args.empty? 283: if block 284: raise(Error, "Defining a dataset method using a block requires only one argument") if args.length > 1 285: meth = args.first 286: @dataset_methods[meth] = block 287: dataset.meta_def(meth, &block) if @dataset 288: end 289: args.each do |arg| 290: if arg.to_s =~ NORMAL_METHOD_NAME_REGEXP 291: instance_eval("def #{arg}(*args, &block); dataset.#{arg}(*args, &block) end", __FILE__, __LINE__) unless respond_to?(arg, true) 292: else 293: def_model_dataset_method_block(arg) 294: end 295: end 296: 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 306 306: def find(*args, &block) 307: filter(*args, &block).first 308: 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 322 322: def find_or_create(cond, &block) 323: find(cond) || create(cond, &block) 324: 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 370 370: def implicit_table_name 371: pluralize(underscore(demodulize(name))).to_sym 372: end
Clear the setter_methods cache when a module is included, as it may contain setter methods.
# File lib/sequel/model/base.rb, line 328 328: def include(mod) 329: clear_setter_methods_cache 330: super 331: 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 342 342: def inherited(subclass) 343: super 344: ivs = subclass.instance_variables.collect{|x| x.to_s} 345: EMPTY_INSTANCE_VARIABLES.each{|iv| subclass.instance_variable_set(iv, nil) unless ivs.include?(iv.to_s)} 346: INHERITED_INSTANCE_VARIABLES.each do |iv, dup| 347: next if ivs.include?(iv.to_s) 348: sup_class_value = instance_variable_get(iv) 349: sup_class_value = sup_class_value.dup if dup == :dup && sup_class_value 350: subclass.instance_variable_set(iv, sup_class_value) 351: end 352: unless ivs.include?("@dataset") 353: if self == Model || !@dataset 354: n = subclass.name 355: unless n.nil? || n.empty? 356: db 357: subclass.set_dataset(subclass.implicit_table_name) rescue nil 358: end 359: elsif @dataset 360: subclass.set_dataset(@dataset.clone, :inherited=>true) rescue nil 361: end 362: end 363: end
Clear the setter_methods cache when a setter method is added
# File lib/sequel/model/base.rb, line 380 380: def method_added(meth) 381: clear_setter_methods_cache if meth.to_s =~ SETTER_METHOD_REGEXP 382: super 383: 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 391 391: def no_primary_key 392: clear_setter_methods_cache 393: self.simple_pk = @primary_key = nil 394: 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 either sequel/plugins/#{plugin} or sequel_#{plugin}, and then attempt to load the module using a the camelized plugin name under Sequel::Plugins.
# File lib/sequel/model/base.rb, line 401 401: def plugin(plugin, *args, &block) 402: m = plugin.is_a?(Module) ? plugin : plugin_module(plugin) 403: unless @plugins.include?(m) 404: @plugins << m 405: m.apply(self, *args, &block) if m.respond_to?(:apply) 406: include(m::InstanceMethods) if plugin_module_defined?(m, :InstanceMethods) 407: extend(m::ClassMethods)if plugin_module_defined?(m, :ClassMethods) 408: dataset_extend(m::DatasetMethods) if plugin_module_defined?(m, :DatasetMethods) 409: end 410: m.configure(self, *args, &block) if m.respond_to?(:configure) 411: 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 421 421: def primary_key_hash(value) 422: raise(Error, "#{self} does not have a primary key") unless key = @primary_key 423: case key 424: when Array 425: hash = {} 426: key.each_with_index{|k,i| hash[k] = value[i]} 427: hash 428: else 429: {key => value} 430: end 431: 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.filter(Artist.qualified_primary_key_hash(1)) # SELECT * FROM artists WHERE (artists.id = 1)
# File lib/sequel/model/base.rb, line 440 440: def qualified_primary_key_hash(value, qualifier=table_name) 441: h = primary_key_hash(value) 442: h.to_a.each{|k,v| h[SQL::QualifiedIdentifier.new(qualifier, k)] = h.delete(k)} 443: h 444: 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 449 449: def restrict_primary_key 450: clear_setter_methods_cache 451: @restrict_primary_key = true 452: 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 456 456: def restrict_primary_key? 457: @restrict_primary_key 458: end
Set the columns to allow when using mass assignment (e.g. set). Using this means that any columns not listed here will not be modified. If you have any virtual setter methods (methods that end in =) that you want to be used during mass assignment, they need to be listed here as well (without the =).
It may be better to use a method such as set_only or set_fields that lets you specify the allowed fields per call.
Artist.set_allowed_columns(:name, :hometown) Artist.set(:name=>'Bob', :hometown=>'Sactown') # No Error Artist.set(:name=>'Bob', :records_sold=>30000) # Error
# File lib/sequel/model/base.rb, line 471 471: def set_allowed_columns(*cols) 472: clear_setter_methods_cache 473: @allowed_columns = cols 474: 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.
This changes the row_proc of the dataset to return model objects, extends the dataset with the dataset_method_modules, and defines methods on the dataset using the dataset_methods. It also attempts to determine the database schema for the model, based on the given dataset.
Artist.set_dataset(:tbl_artists) Artist.set_dataset(DB[:artists])
# File lib/sequel/model/base.rb, line 493 493: def set_dataset(ds, opts={}) 494: inherited = opts[:inherited] 495: @dataset = case ds 496: when Symbol, SQL::Identifier, SQL::QualifiedIdentifier, SQL::AliasedExpression, LiteralString 497: self.simple_table = db.literal(ds) 498: db.from(ds) 499: when Dataset 500: self.simple_table = if ds.send(:simple_select_all?) 501: ds.literal(ds.first_source_table) 502: else 503: nil 504: end 505: @db = ds.db 506: ds 507: else 508: raise(Error, "Model.set_dataset takes one of the following classes as an argument: Symbol, LiteralString, SQL::Identifier, SQL::QualifiedIdentifier, SQL::AliasedExpression, Dataset") 509: end 510: @dataset.row_proc = self 511: @require_modification = Sequel::Model.require_modification.nil? ? @dataset.provides_accurate_rows_matched? : Sequel::Model.require_modification 512: if inherited 513: self.simple_table = superclass.simple_table 514: @columns = @dataset.columns rescue nil 515: else 516: @dataset_method_modules.each{|m| @dataset.extend(m)} if @dataset_method_modules 517: @dataset_methods.each{|meth, block| @dataset.meta_def(meth, &block)} if @dataset_methods 518: end 519: @dataset.model = self if @dataset.respond_to?(:model=) 520: check_non_connection_error{@db_schema = (inherited ? superclass.db_schema : get_db_schema)} 521: @instance_dataset = @dataset.limit(1).naked 522: self 523: 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 539 539: def set_primary_key(*key) 540: clear_setter_methods_cache 541: key = key.flatten 542: self.simple_pk = if key.length == 1 543: (@dataset || db).literal(key.first) 544: else 545: nil 546: end 547: @primary_key = (key.length == 1) ? key[0] : key 548: end
Set the columns to restrict when using mass assignment (e.g. set). Using this means that attempts to call setter methods for the columns listed here will cause an exception or be silently skipped (based on the strict_param_setting setting). If you have any virtual setter methods (methods that end in =) that you want not to be used during mass assignment, they need to be listed here as well (without the =).
It‘s generally a bad idea to rely on a blacklist approach for security. Using a whitelist approach such as set_allowed_columns or the instance level set_only or set_fields methods is usually a better choice. So use of this method is generally a bad idea.
Artist.set_restricted_column(:records_sold) Artist.set(:name=>'Bob', :hometown=>'Sactown') # No Error Artist.set(:name=>'Bob', :records_sold=>30000) # Error
# File lib/sequel/model/base.rb, line 563 563: def set_restricted_columns(*cols) 564: clear_setter_methods_cache 565: @restricted_columns = cols 566: end
Cache of setter methods to allow by default, in order to speed up new/set/update instance methods.
# File lib/sequel/model/base.rb, line 569 569: def setter_methods 570: @setter_methods ||= if allowed_columns 571: allowed_columns.map{|x| "#{x}="} 572: else 573: meths = instance_methods.collect{|x| x.to_s}.grep(SETTER_METHOD_REGEXP) - RESTRICTED_SETTER_METHODS 574: meths -= Array(primary_key).map{|x| "#{x}="} if primary_key && restrict_primary_key? 575: meths -= restricted_columns.map{|x| "#{x}="} if restricted_columns 576: meths 577: end 578: end
Shortcut for def_dataset_method that is restricted to modifying the dataset‘s filter. Sometimes thought of as a scope, and like most dataset methods, they can be chained. For example:
Topic.subset(:joes, :username.like('%joe%')) Topic.subset(:popular){num_posts > 100} Topic.subset(:recent){created_on > Date.today - 7}
Allows you to do:
Topic.joes.recent.popular
to get topics with a username that includes joe that have more than 100 posts and were created less than 7 days ago.
Both the args given and the block are passed to Dataset#filter.
This method creates dataset methods that do not accept arguments. To create dataset methods that accept arguments, you have to use def_dataset_method.
# File lib/sequel/model/base.rb, line 601 601: def subset(name, *args, &block) 602: def_dataset_method(name){filter(*args, &block)} 603: 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(:foo___bar).table_name # => :bar
# File lib/sequel/model/base.rb, line 611 611: def table_name 612: dataset.first_source_alias 613: 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 621 621: def unrestrict_primary_key 622: clear_setter_methods_cache 623: @restrict_primary_key = false 624: end