Translates a query block into a dataset. Query blocks are an alternative to Sequel‘s usual method chaining, by using instance_exec with a proxy object:

  dataset = DB[:items].query do
    select :x, :y, :z
    where{(x > 1) & (y > 2)}
    reverse :z
  end

Which is the same as:

 dataset = DB[:items].select(:x, :y, :z).where{(x > 1) & (y > 2)}.reverse(:z)

[Source]

    # File lib/sequel/extensions/query.rb, line 53
53:     def query(&block)
54:       query = Dataset::Query.new(self)
55:       query.instance_exec(&block)
56:       query.dataset
57:     end