Module | Sequel::Model::ClassMethods |
In: |
lib/sequel/model/plugins.rb
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 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 plugins loaded by this class |
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).
# File lib/sequel/model/base.rb, line 92 92: def [](*args) 93: args = args.first if (args.size == 1) 94: args.is_a?(Hash) ? dataset[args] : primary_key_lookup(args) 95: 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, which may be empty if the Dataset has no records.
# File lib/sequel/model/base.rb, line 102 102: def columns 103: @columns || set_columns(dataset.naked.columns) 104: end
Creates instance using new with the given values and block, and saves it.
# File lib/sequel/model/base.rb, line 107 107: def create(values = {}, &block) 108: new(values, &block).save 109: end
Alias of set_dataset
# File lib/sequel/model/base.rb, line 118 118: def dataset=(ds) 119: set_dataset(ds) 120: 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.
# File lib/sequel/model/base.rb, line 127 127: def db 128: return @db if @db 129: @db = self == Model ? DATABASES.first : superclass.db 130: raise(Error, "No database associated with #{self}") unless @db 131: @db 132: 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.
# File lib/sequel/model/base.rb, line 138 138: def db=(db) 139: @db = db 140: set_dataset(db.dataset(@dataset.opts)) if @dataset 141: end
Returns the cached schema information if available or gets it from the database.
# File lib/sequel/model/base.rb, line 145 145: def db_schema 146: @db_schema ||= get_db_schema 147: end
If a block is given, define a method on the dataset (if the model has an associated dataset) with the given argument name using the given block as well as a 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, define a method on the model for each argument that calls the dataset method of the same argument name.
# File lib/sequel/model/base.rb, line 156 156: def def_dataset_method(*args, &block) 157: raise(Error, "No arguments given") if args.empty? 158: if block_given? 159: raise(Error, "Defining a dataset method using a block requires only one argument") if args.length > 1 160: meth = args.first 161: @dataset_methods[meth] = block 162: dataset.meta_def(meth, &block) if @dataset 163: end 164: args.each{|arg| instance_eval("def #{arg}(*args, &block); dataset.#{arg}(*args, &block) end", __FILE__, __LINE__) unless respond_to?(arg)} 165: end
Finds a single record according to the supplied filter, e.g.:
Ticket.find :author => 'Sharon' # => record
You are encouraged to use Model.[] or Model.first instead of this method.
# File lib/sequel/model/base.rb, line 172 172: def find(*args, &block) 173: filter(*args, &block).first 174: end
Returns the implicit table name for the model class.
# File lib/sequel/model/base.rb, line 210 210: def implicit_table_name 211: pluralize(underscore(demodulize(name))).to_sym 212: 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.
# File lib/sequel/model/base.rb, line 185 185: def inherited(subclass) 186: super 187: ivs = subclass.instance_variables.collect{|x| x.to_s} 188: EMPTY_INSTANCE_VARIABLES.each{|iv| subclass.instance_variable_set(iv, nil) unless ivs.include?(iv.to_s)} 189: INHERITED_INSTANCE_VARIABLES.each do |iv, dup| 190: next if ivs.include?(iv.to_s) 191: sup_class_value = instance_variable_get(iv) 192: sup_class_value = sup_class_value.dup if dup == :dup && sup_class_value 193: subclass.instance_variable_set(iv, sup_class_value) 194: end 195: unless ivs.include?("@dataset") 196: db 197: begin 198: if self == Model || !@dataset 199: subclass.set_dataset(subclass.implicit_table_name) unless subclass.name.empty? 200: elsif @dataset 201: subclass.set_dataset(@dataset.clone, :inherited=>true) 202: end 203: rescue 204: nil 205: end 206: end 207: 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 218 218: def load(values) 219: new(values, true) 220: 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.
# File lib/sequel/model/base.rb, line 224 224: def no_primary_key 225: @simple_pk = @primary_key = nil 226: 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.
# File lib/sequel/model/base.rb, line 233 233: def primary_key_hash(value) 234: raise(Error, "#{self} does not have a primary key") unless key = @primary_key 235: case key 236: when Array 237: hash = {} 238: key.each_with_index{|k,i| hash[k] = value[i]} 239: hash 240: else 241: {key => value} 242: end 243: end
Return a hash where the keys are qualified column references. Uses the given qualifier if provided, or the table_name otherwise.
# File lib/sequel/model/base.rb, line 247 247: def qualified_primary_key_hash(value, qualifier=table_name) 248: h = primary_key_hash(value) 249: h.to_a.each{|k,v| h[SQL::QualifiedIdentifier.new(qualifier, k)] = h.delete(k)} 250: h 251: end
Restrict the setting of the primary key(s) inside new/set/update. 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 256 256: def restrict_primary_key 257: @restrict_primary_key = true 258: end
Whether or not setting the primary key inside new/set/update is restricted, true by default.
# File lib/sequel/model/base.rb, line 262 262: def restrict_primary_key? 263: @restrict_primary_key 264: end
Set the columns to allow in new/set/update. 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 in new/set/update, they need to be listed here as well (without the =).
It may be better to use (set|update)_only instead of this in places where only certain columns may be allowed.
# File lib/sequel/model/base.rb, line 273 273: def set_allowed_columns(*cols) 274: @allowed_columns = cols 275: 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 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 given 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.
# File lib/sequel/model/base.rb, line 289 289: def set_dataset(ds, opts={}) 290: inherited = opts[:inherited] 291: @dataset = case ds 292: when Symbol 293: @simple_table = db.literal(ds) 294: db[ds] 295: when Dataset 296: @simple_table = nil 297: @db = ds.db 298: ds 299: else 300: raise(Error, "Model.set_dataset takes a Symbol or a Sequel::Dataset") 301: end 302: @dataset.row_proc = Proc.new{|r| load(r)} 303: @require_modification = Sequel::Model.require_modification.nil? ? @dataset.provides_accurate_rows_matched? : Sequel::Model.require_modification 304: if inherited 305: @simple_table = superclass.simple_table 306: @columns = @dataset.columns rescue nil 307: else 308: @dataset_method_modules.each{|m| @dataset.extend(m)} if @dataset_method_modules 309: @dataset_methods.each{|meth, block| @dataset.meta_def(meth, &block)} if @dataset_methods 310: end 311: @dataset.model = self if @dataset.respond_to?(:model=) 312: check_non_connection_error{@db_schema = (inherited ? superclass.db_schema : get_db_schema)} 313: self 314: end
Sets the primary key for this model. You can use either a regular or a composite primary key.
Example:
class Tagging < Sequel::Model # composite key set_primary_key [:taggable_id, :tag_id] end class Person < Sequel::Model # regular key set_primary_key :person_id end
You can set it to nil to not have a primary key, but that cause certain things not to work, see no_primary_key.
# File lib/sequel/model/base.rb, line 332 332: def set_primary_key(*key) 333: key = key.flatten 334: @simple_pk = key.length == 1 ? db.literal(key.first) : nil 335: @primary_key = (key.length == 1) ? key[0] : key 336: end
Set the columns to restrict in new/set/update. 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 in new/set/update, they need to be listed here as well (without the =).
It may be better to use (set|update)_except instead of this in places where only certain columns may be allowed.
# File lib/sequel/model/base.rb, line 346 346: def set_restricted_columns(*cols) 347: @restricted_columns = cols 348: end
Defines a method that returns a filtered dataset. Subsets create dataset methods, so they can be chained for scoping. For example:
Topic.subset(:joes, :username.like('%joe%')) Topic.subset(:popular){|o| o.num_posts > 100} Topic.subset(:recent){|o| o.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 367 367: def subset(name, *args, &block) 368: def_dataset_method(name){filter(*args, &block)} 369: end