Module: Sequel::Model::DatasetMethods
- Defined in:
- lib/sequel/model/base.rb
Overview
DatasetMethods contains methods that all model datasets have.
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.
-
#as_hash(key_column = nil, value_column = nil, opts = OPTS) ⇒ Object
This allows you to call
as_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. -
#destroy ⇒ Object
Destroy each row in the dataset by instantiating it and then calling destroy on the resulting model object.
-
#last(*a, &block) ⇒ Object
If there is no order already defined on this dataset, order it by the primary key and call last.
-
#model ⇒ Object
The model class associated with this dataset.
-
#paged_each(*a, &block) ⇒ Object
If there is no order already defined on this dataset, order it by the primary key and call paged_each.
-
#to_hash(*a) ⇒ Object
Alias of as_hash for backwards compatibility.
-
#with_pk(pk) ⇒ Object
Given a primary key value, return the first record in the dataset with that primary key value.
-
#with_pk!(pk) ⇒ Object
Same as with_pk, but raises NoMatchingRow instead of returning nil if no row matches.
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 2106 def [](*args) if args.length == 1 && (i = args[0]) && i.is_a?(Integer) with_pk(i) else super end end |
#as_hash(key_column = nil, value_column = nil, opts = OPTS) ⇒ Object
This allows you to call as_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.as_hash # SELECT * FROM artists
# => {1=>#<Artist {:id=>1, ...}>,
# 2=>#<Artist {:id=>2, ...}>,
# ...}
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# File 'lib/sequel/model/base.rb', line 2165 def as_hash(key_column=nil, value_column=nil, opts=OPTS) if key_column super else raise(Sequel::Error, "No primary key for model") unless model && (pk = model.primary_key) super(pk, value_column, opts) 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 2123 def destroy pr = proc{all(&:destroy).length} model.use_transactions ? @db.transaction(:server=>opts[:server], &pr) : pr.call end |
#last(*a, &block) ⇒ Object
If there is no order already defined on this dataset, order it by the primary key and call last.
Album.last
# SELECT * FROM albums ORDER BY id DESC LIMIT 1
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# File 'lib/sequel/model/base.rb', line 2133 def last(*a, &block) if ds = _primary_key_order ds.last(*a, &block) else super end end |
#model ⇒ Object
The model class associated with this dataset
Artist.dataset.model # => Artist
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# File 'lib/sequel/model/base.rb', line 2098 def model @opts[:model] end |
#paged_each(*a, &block) ⇒ Object
If there is no order already defined on this dataset, order it by the primary key and call paged_each.
Album.paged_each{|row| }
# SELECT * FROM albums ORDER BY id LIMIT 1000 OFFSET 0
# SELECT * FROM albums ORDER BY id LIMIT 1000 OFFSET 1000
# SELECT * FROM albums ORDER BY id LIMIT 1000 OFFSET 2000
# ...
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# File 'lib/sequel/model/base.rb', line 2149 def paged_each(*a, &block) if ds = _primary_key_order ds.paged_each(*a, &block) else super end end |
#to_hash(*a) ⇒ Object
Alias of as_hash for backwards compatibility.
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# File 'lib/sequel/model/base.rb', line 2175 def to_hash(*a) as_hash(*a) end |
#with_pk(pk) ⇒ Object
Given a primary key value, return the first record in the dataset with that primary key value. If no records matches, returns nil.
# Single primary key
Artist.dataset.with_pk(1)
# SELECT * FROM artists WHERE (artists.id = 1) LIMIT 1
# Composite primary key
Artist.dataset.with_pk([1, 2])
# SELECT * FROM artists WHERE ((artists.id1 = 1) AND (artists.id2 = 2)) LIMIT 1
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# File 'lib/sequel/model/base.rb', line 2189 def with_pk(pk) if pk && (loader = _with_pk_loader) loader.first(*pk) else first(model.qualified_primary_key_hash(pk)) end end |
#with_pk!(pk) ⇒ Object
Same as with_pk, but raises NoMatchingRow instead of returning nil if no row matches.
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# File 'lib/sequel/model/base.rb', line 2199 def with_pk!(pk) with_pk(pk) || raise(NoMatchingRow.new(self)) end |