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.
Class methods for Sequel::Model that implement basic model functionality.
All of the method names in Model::DATASET_METHODS have class methods created that call the Model's dataset with the method of the same name with the given arguments.
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).
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.
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.
Array of plugin modules loaded by this class
Sequel::Model.plugins # => [Sequel::Model, Sequel::Model::Associations]
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.
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.
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.
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).
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.
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.
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.
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.
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 104 def [](*args) args = args.first if (args.size == 1) args.is_a?(Hash) ? dataset[args] : primary_key_lookup(args) 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 113 def call(values) o = allocate o.set_values(values) o.after_initialize o end
Clear the setter_methods cache
# File lib/sequel/model/base.rb, line 121 def clear_setter_methods_cache @setter_methods = nil 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 132 def columns @columns || set_columns(dataset.naked.columns) 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 144 def create(values = {}, &block) new(values, &block).save 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 154 def dataset @dataset || raise(Error, "No dataset associated with #{self}") end
Alias of set_dataset
# File lib/sequel/model/base.rb, line 159 def dataset=(ds) set_dataset(ds) 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 180 def dataset_module(mod = nil) if mod raise Error, "can't provide both argument and block to Model.dataset_module" if block_given? dataset_extend(mod) mod else @dataset_module ||= Module.new @dataset_module.module_eval(&Proc.new) if block_given? dataset_extend(@dataset_module) @dataset_module end 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 203 def db return @db if @db @db = self == Model ? DATABASES.first : superclass.db raise(Error, "No database associated with #{self}: have you called Sequel.connect or #{self}.db= ?") unless @db @db 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 220 def db=(db) @db = db set_dataset(db.dataset(@dataset.opts)) if @dataset 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 233 def db_schema @db_schema ||= get_db_schema 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 239 def def_column_alias(meth, column) clear_setter_methods_cache overridable_methods_module.module_eval do define_method(meth){self[column]} define_method("#{meth}="){|v| self[column] = v} end 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 263 def def_dataset_method(*args, &block) raise(Error, "No arguments given") if args.empty? if block raise(Error, "Defining a dataset method using a block requires only one argument") if args.length > 1 meth = args.first @dataset_methods[meth] = block dataset.meta_def(meth, &block) if @dataset end args.each do |arg| if arg.to_s =~ NORMAL_METHOD_NAME_REGEXP instance_eval("def #{arg}(*args, &block); dataset.#{arg}(*args, &block) end", __FILE__, __LINE__) unless respond_to?(arg, true) else def_model_dataset_method_block(arg) end end 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 303 def find(*args, &block) filter(*args, &block).first 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 319 def find_or_create(cond, &block) find(cond) || create(cond, &block) 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 369 def implicit_table_name pluralize(underscore(demodulize(name))).to_sym end
Clear the setter_methods cache when a module is included, as it may contain setter methods.
# File lib/sequel/model/base.rb, line 325 def include(mod) clear_setter_methods_cache super 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 339 def inherited(subclass) super ivs = subclass.instance_variables.collect{|x| x.to_s} EMPTY_INSTANCE_VARIABLES.each{|iv| subclass.instance_variable_set(iv, nil) unless ivs.include?(iv.to_s)} INHERITED_INSTANCE_VARIABLES.each do |iv, dup| next if ivs.include?(iv.to_s) sup_class_value = instance_variable_get(iv) sup_class_value = sup_class_value.dup if dup == :dup && sup_class_value subclass.instance_variable_set(iv, sup_class_value) end unless ivs.include?("@dataset") db begin if self == Model || !@dataset n = subclass.name subclass.set_dataset(subclass.implicit_table_name) unless n.nil? || n.empty? elsif @dataset subclass.set_dataset(@dataset.clone, :inherited=>true) end rescue nil end end end
Calls call with the values hash. Only for backwards compatibility.
# File lib/sequel/model/base.rb, line 374 def load(values) call(values) end
Clear the setter_methods cache when a setter method is added
# File lib/sequel/model/base.rb, line 379 def method_added(meth) clear_setter_methods_cache if meth.to_s =~ SETTER_METHOD_REGEXP super 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 390 def no_primary_key clear_setter_methods_cache @simple_pk = @primary_key = nil 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 400 def plugin(plugin, *args, &blk) m = plugin.is_a?(Module) ? plugin : plugin_module(plugin) unless @plugins.include?(m) @plugins << m m.apply(self, *args, &blk) if m.respond_to?(:apply) include(m::InstanceMethods) if plugin_module_defined?(m, :InstanceMethods) extend(m::ClassMethods)if plugin_module_defined?(m, :ClassMethods) dataset_extend(m::DatasetMethods) if plugin_module_defined?(m, :DatasetMethods) end m.configure(self, *args, &blk) if m.respond_to?(:configure) 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 420 def primary_key_hash(value) raise(Error, "#{self} does not have a primary key") unless key = @primary_key case key when Array hash = {} key.each_with_index{|k,i| hash[k] = value[i]} hash else {key => value} end 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 439 def qualified_primary_key_hash(value, qualifier=table_name) h = primary_key_hash(value) h.to_a.each{|k,v| h[SQL::QualifiedIdentifier.new(qualifier, k)] = h.delete(k)} h 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 448 def restrict_primary_key clear_setter_methods_cache @restrict_primary_key = true 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 455 def restrict_primary_key? @restrict_primary_key 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 470 def set_allowed_columns(*cols) clear_setter_methods_cache @allowed_columns = cols 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 492 def set_dataset(ds, opts={}) inherited = opts[:inherited] @dataset = case ds when Symbol, SQL::Identifier, SQL::QualifiedIdentifier, SQL::AliasedExpression, LiteralString @simple_table = db.literal(ds) db.from(ds) when Dataset @simple_table = if ds.send(:simple_select_all?) ds.literal(ds.first_source_table) else nil end @db = ds.db ds else raise(Error, "Model.set_dataset takes one of the following classes as an argument: Symbol, LiteralString, SQL::Identifier, SQL::QualifiedIdentifier, SQL::AliasedExpression, Dataset") end @dataset.row_proc = self @require_modification = Sequel::Model.require_modification.nil? ? @dataset.provides_accurate_rows_matched? : Sequel::Model.require_modification if inherited @simple_table = superclass.simple_table @columns = @dataset.columns rescue nil else @dataset_method_modules.each{|m| @dataset.extend(m)} if @dataset_method_modules @dataset_methods.each{|meth, block| @dataset.meta_def(meth, &block)} if @dataset_methods end @dataset.model = self if @dataset.respond_to?(:model=) check_non_connection_error{@db_schema = (inherited ? superclass.db_schema : get_db_schema)} self 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 537 def set_primary_key(*key) clear_setter_methods_cache key = key.flatten @simple_pk = if key.length == 1 (@dataset || db).literal(key.first) else nil end @primary_key = (key.length == 1) ? key[0] : key 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 561 def set_restricted_columns(*cols) clear_setter_methods_cache @restricted_columns = cols 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 567 def setter_methods @setter_methods ||= if allowed_columns allowed_columns.map{|x| "#{x}="} else meths = instance_methods.collect{|x| x.to_s}.grep(SETTER_METHOD_REGEXP) - RESTRICTED_SETTER_METHODS meths -= Array(primary_key).map{|x| "#{x}="} if primary_key && restrict_primary_key? meths -= restricted_columns.map{|x| "#{x}="} if restricted_columns meths end 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 599 def subset(name, *args, &block) def_dataset_method(name){filter(*args, &block)} 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 609 def table_name dataset.first_source_alias 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 619 def unrestrict_primary_key clear_setter_methods_cache @restrict_primary_key = false end
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