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). |
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. |
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_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 104 104: def [](*args) 105: args = args.first if (args.size == 1) 106: args.is_a?(Hash) ? dataset[args] : primary_key_lookup(args) 107: end
Clear the setter_methods cache
# File lib/sequel/model/base.rb, line 110 110: def clear_setter_methods_cache 111: @setter_methods = nil 112: 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 121 121: def columns 122: @columns || set_columns(dataset.naked.columns) 123: 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 133 133: def create(values = {}, &block) 134: new(values, &block).save 135: 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 143 143: def dataset 144: @dataset || raise(Error, "No dataset associated with #{self}") 145: end
Alias of set_dataset
# File lib/sequel/model/base.rb, line 148 148: def dataset=(ds) 149: set_dataset(ds) 150: 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 162 162: def db 163: return @db if @db 164: @db = self == Model ? DATABASES.first : superclass.db 165: raise(Error, "No database associated with #{self}: have you called Sequel.connect or #{self}.db= ?") unless @db 166: @db 167: 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 179 179: def db=(db) 180: @db = db 181: set_dataset(db.dataset(@dataset.opts)) if @dataset 182: 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 192 192: def db_schema 193: @db_schema ||= get_db_schema 194: 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 212 212: def def_dataset_method(*args, &block) 213: raise(Error, "No arguments given") if args.empty? 214: if block 215: raise(Error, "Defining a dataset method using a block requires only one argument") if args.length > 1 216: meth = args.first 217: @dataset_methods[meth] = block 218: dataset.meta_def(meth, &block) if @dataset 219: end 220: args.each{|arg| instance_eval("def #{arg}(*args, &block); dataset.#{arg}(*args, &block) end", __FILE__, __LINE__) unless respond_to?(arg)} 221: 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 231 231: def find(*args, &block) 232: filter(*args, &block).first 233: 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 247 247: def find_or_create(cond, &block) 248: find(cond) || create(cond, &block) 249: 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 290 290: def implicit_table_name 291: pluralize(underscore(demodulize(name))).to_sym 292: 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 260 260: def inherited(subclass) 261: super 262: ivs = subclass.instance_variables.collect{|x| x.to_s} 263: EMPTY_INSTANCE_VARIABLES.each{|iv| subclass.instance_variable_set(iv, nil) unless ivs.include?(iv.to_s)} 264: INHERITED_INSTANCE_VARIABLES.each do |iv, dup| 265: next if ivs.include?(iv.to_s) 266: sup_class_value = instance_variable_get(iv) 267: sup_class_value = sup_class_value.dup if dup == :dup && sup_class_value 268: subclass.instance_variable_set(iv, sup_class_value) 269: end 270: unless ivs.include?("@dataset") 271: db 272: begin 273: if self == Model || !@dataset 274: n = subclass.name 275: subclass.set_dataset(subclass.implicit_table_name) unless n.nil? || n.empty? 276: elsif @dataset 277: subclass.set_dataset(@dataset.clone, :inherited=>true) 278: end 279: rescue 280: nil 281: end 282: end 283: end
Initializes a model instance as an existing record. This constructor is used by Sequel to initialize model instances when fetching records. load 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 298 298: def load(values) 299: new(values, true) 300: end
Clear the setter_methods cache when a setter method is added
# File lib/sequel/model/base.rb, line 303 303: def method_added(meth) 304: clear_setter_methods_cache if meth.to_s =~ SETTER_METHOD_REGEXP 305: super 306: 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 314 314: def no_primary_key 315: clear_setter_methods_cache 316: @simple_pk = @primary_key = nil 317: 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 324 324: def plugin(plugin, *args, &blk) 325: m = plugin.is_a?(Module) ? plugin : plugin_module(plugin) 326: unless @plugins.include?(m) 327: @plugins << m 328: m.apply(self, *args, &blk) if m.respond_to?(:apply) 329: include(m::InstanceMethods) if m.const_defined?("InstanceMethods") 330: extend(m::ClassMethods)if m.const_defined?("ClassMethods") 331: if m.const_defined?("DatasetMethods") 332: dataset.extend(m::DatasetMethods) if @dataset 333: dataset_method_modules << m::DatasetMethods 334: meths = m::DatasetMethods.public_instance_methods.reject{|x| NORMAL_METHOD_NAME_REGEXP !~ x.to_s} 335: def_dataset_method(*meths) unless meths.empty? 336: end 337: end 338: m.configure(self, *args, &blk) if m.respond_to?(:configure) 339: 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 349 349: def primary_key_hash(value) 350: raise(Error, "#{self} does not have a primary key") unless key = @primary_key 351: case key 352: when Array 353: hash = {} 354: key.each_with_index{|k,i| hash[k] = value[i]} 355: hash 356: else 357: {key => value} 358: end 359: 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 368 368: def qualified_primary_key_hash(value, qualifier=table_name) 369: h = primary_key_hash(value) 370: h.to_a.each{|k,v| h[SQL::QualifiedIdentifier.new(qualifier, k)] = h.delete(k)} 371: h 372: 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 377 377: def restrict_primary_key 378: clear_setter_methods_cache 379: @restrict_primary_key = true 380: 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 384 384: def restrict_primary_key? 385: @restrict_primary_key 386: 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 instead of this in places where only certain columns may be allowed.
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 399 399: def set_allowed_columns(*cols) 400: clear_setter_methods_cache 401: @allowed_columns = cols 402: end
Sets the dataset associated with the Model class. ds can be a Symbol (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 symbol is 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 419 419: def set_dataset(ds, opts={}) 420: inherited = opts[:inherited] 421: @dataset = case ds 422: when Symbol 423: @simple_table = db.literal(ds) 424: db[ds] 425: when Dataset 426: @simple_table = nil 427: @db = ds.db 428: ds 429: else 430: raise(Error, "Model.set_dataset takes a Symbol or a Sequel::Dataset") 431: end 432: @dataset.row_proc = Proc.new{|r| load(r)} 433: @require_modification = Sequel::Model.require_modification.nil? ? @dataset.provides_accurate_rows_matched? : Sequel::Model.require_modification 434: if inherited 435: @simple_table = superclass.simple_table 436: @columns = @dataset.columns rescue nil 437: else 438: @dataset_method_modules.each{|m| @dataset.extend(m)} if @dataset_method_modules 439: @dataset_methods.each{|meth, block| @dataset.meta_def(meth, &block)} if @dataset_methods 440: end 441: @dataset.model = self if @dataset.respond_to?(:model=) 442: check_non_connection_error{@db_schema = (inherited ? superclass.db_schema : get_db_schema)} 443: self 444: 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.
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 459 459: def set_primary_key(*key) 460: clear_setter_methods_cache 461: key = key.flatten 462: @simple_pk = key.length == 1 ? db.literal(key.first) : nil 463: @primary_key = (key.length == 1) ? key[0] : key 464: 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 may be better to use a method such as set_except instead of this in places where certain columns are restricted. In general, it‘s better to have a whitelist approach where you specify only what is allowed, as opposed to a blacklist approach that this method uses, where everything is allowed other than what you restrict.
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 480 480: def set_restricted_columns(*cols) 481: clear_setter_methods_cache 482: @restricted_columns = cols 483: 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 486 486: def setter_methods 487: @setter_methods ||= if allowed_columns 488: allowed_columns.map{|x| "#{x}="} 489: else 490: meths = instance_methods.collect{|x| x.to_s}.grep(SETTER_METHOD_REGEXP) - RESTRICTED_SETTER_METHODS 491: meths -= Array(primary_key).map{|x| "#{x}="} if primary_key && restrict_primary_key? 492: meths -= restricted_columns.map{|x| "#{x}="} if restricted_columns 493: meths 494: end 495: 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.
# File lib/sequel/model/base.rb, line 515 515: def subset(name, *args, &block) 516: def_dataset_method(name){filter(*args, &block)} 517: 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 525 525: def table_name 526: dataset.first_source_alias 527: end
Allow the setting of the primary key(s) when using the mass assignment methods.
Artist.set(:id=>1) # Error Artist.unrestrict_primary_key Artist.set(:id=>1) # No Error
# File lib/sequel/model/base.rb, line 534 534: def unrestrict_primary_key 535: clear_setter_methods_cache 536: @restrict_primary_key = false 537: end