Module: Sequel::Model::DatasetMethods

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

[Source]

      # File lib/sequel/model/base.rb, line 2037
2037:       def [](*args)
2038:         if args.length == 1 && (i = args[0]) && i.is_a?(Integer)
2039:           with_pk(i)
2040:         else
2041:           super
2042:         end
2043:       end

as_hash(key_column=nil, value_column=nil, opts=OPTS)

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, ...}>,
  #     ...}

[Source]

      # File lib/sequel/model/base.rb, line 2096
2096:       def as_hash(key_column=nil, value_column=nil, opts=OPTS)
2097:         if key_column
2098:           super
2099:         else
2100:           raise(Sequel::Error, "No primary key for model") unless model && (pk = model.primary_key)
2101:           super(pk, value_column, opts) 
2102:         end
2103:       end

destroy()

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)
  # ...

[Source]

      # File lib/sequel/model/base.rb, line 2054
2054:       def destroy
2055:         pr = proc{all(&:destroy).length}
2056:         model.use_transactions ? @db.transaction(:server=>opts[:server], &pr) : pr.call
2057:       end

last(*a, &block)

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

[Source]

      # File lib/sequel/model/base.rb, line 2064
2064:       def last(*a, &block)
2065:         if ds = _primary_key_order
2066:           ds.last(*a, &block)
2067:         else
2068:           super
2069:         end
2070:       end

model()

The model class associated with this dataset

  Artist.dataset.model # => Artist

[Source]

      # File lib/sequel/model/base.rb, line 2029
2029:       def model
2030:         @opts[:model]
2031:       end

paged_each(*a, &block)

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
  # ...

[Source]

      # File lib/sequel/model/base.rb, line 2080
2080:       def paged_each(*a, &block)
2081:         if ds = _primary_key_order
2082:           ds.paged_each(*a, &block)
2083:         else
2084:           super
2085:         end
2086:       end

to_hash(*a)

Alias of as_hash for backwards compatibility.

[Source]

      # File lib/sequel/model/base.rb, line 2106
2106:       def to_hash(*a)
2107:         as_hash(*a)
2108:       end

with_pk(pk)

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

[Source]

      # File lib/sequel/model/base.rb, line 2120
2120:       def with_pk(pk)
2121:         if pk && (loader = _with_pk_loader)
2122:           loader.first(*pk)
2123:         else
2124:           first(model.qualified_primary_key_hash(pk))
2125:         end
2126:       end

with_pk!(pk)

Same as with_pk, but raises NoMatchingRow instead of returning nil if no row matches.

[Source]

      # File lib/sequel/model/base.rb, line 2130
2130:       def with_pk!(pk)
2131:         with_pk(pk) || raise(NoMatchingRow.new(self))
2132:       end

Methods

Public Instance methods