Module: Sequel::Model::DatasetMethods
- Defined in:
- lib/sequel/model/base.rb
Overview
Dataset methods are methods that the model class extends its dataset with in the call to set_dataset.
Instance Attribute Summary collapse
-
#model ⇒ Object
The model class associated with this dataset.
Instance Method Summary collapse
-
#[](*args) ⇒ Object
Assume if a single integer is given that it is a lookup by primary key, and call with_pk with the argument.
-
#destroy ⇒ Object
Destroy each row in the dataset by instantiating it and then calling destroy on the resulting model object.
-
#to_hash(key_column = nil, value_column = nil) ⇒ Object
This allows you to call
to_hash
without any arguments, which will result in a hash with the primary key value being the key and the model object being the value. -
#with_pk(pk) ⇒ Object
Given a primary key value, return the first record in the dataset with that primary key value.
Instance Attribute Details
#model ⇒ Object
The model class associated with this dataset
Artist.dataset.model # => Artist
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# File 'lib/sequel/model/base.rb', line 1724 def model @model end |
Instance Method Details
#[](*args) ⇒ Object
Assume if a single integer is given that it is a lookup by primary key, and call with_pk with the argument.
Artist.dataset[1] # SELECT * FROM artists WHERE (id = 1) LIMIT 1
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# File 'lib/sequel/model/base.rb', line 1730 def [](*args) if args.length == 1 && (i = args.at(0)) && i.is_a?(Integer) with_pk(i) else super end end |
#destroy ⇒ Object
Destroy each row in the dataset by instantiating it and then calling destroy on the resulting model object. This isn’t as fast as deleting the dataset, which does a single SQL call, but this runs any destroy hooks on each object in the dataset.
Artist.dataset.destroy
# DELETE FROM artists WHERE (id = 1)
# DELETE FROM artists WHERE (id = 2)
# ...
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# File 'lib/sequel/model/base.rb', line 1747 def destroy pr = proc{all{|r| r.destroy}.length} model.use_transactions ? @db.transaction(:server=>opts[:server], &pr) : pr.call end |
#to_hash(key_column = nil, value_column = nil) ⇒ Object
This allows you to call to_hash
without any arguments, which will result in a hash with the primary key value being the key and the model object being the value.
Artist.dataset.to_hash # SELECT * FROM artists
# => {1=>#<Artist {:id=>1, ...}>,
# 2=>#<Artist {:id=>2, ...}>,
# ...}
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# File 'lib/sequel/model/base.rb', line 1760 def to_hash(key_column=nil, value_column=nil) if key_column super else raise(Sequel::Error, "No primary key for model") unless model and pk = model.primary_key super(pk, value_column) end end |
#with_pk(pk) ⇒ Object
Given a primary key value, return the first record in the dataset with that primary key value.
# Single primary key
Artist.dataset.with_pk(1) # SELECT * FROM artists WHERE (id = 1) LIMIT 1
# Composite primary key
Artist.dataset.with_pk([1, 2]) # SELECT * FROM artists
# WHERE ((id1 = 1) AND (id2 = 2)) LIMIT 1
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# File 'lib/sequel/model/base.rb', line 1778 def with_pk(pk) first(model.qualified_primary_key_hash(pk)) end |