Class: ConceptQL::Operators::Union

Inherits:
PassThru show all
Defined in:
lib/conceptql/operators/union.rb

Instance Attribute Summary

Attributes inherited from Operator

#arguments, #errors, #nodifier, #options, #upstreams, #values

Instance Method Summary collapse

Methods inherited from PassThru

#domains, #query_cols

Methods inherited from Operator

#annotate, #cast_column, #code_list, codes_should_match, #columns, #create_upstreams, #data_model, #database_type, default_query_columns, #domains, #dup_values, #dynamic_columns, #evaluate, inherited, #initialize, #inspect, #label, new, #operator_name, query_columns, register, require_column, #required_columns, #scope, #select_it, #setup_select, #sql, #stream, #to_op, #unionable?, #upstreams_valid?, #valid?

Methods included from Metadatable

#allows_many_upstreams, #allows_one_upstream, #argument, #auto_label, #basic_type, #category, #derive_metadata_from_validations, #desc, #domains, #get_desc, #humanized_class_name, #inherited, #just_class_name, #no_desc, #option, #predominant_domains, #pref_name, #preferred_name, #reset_categories, #standard_description, #to_metadata, #validate_at_least_one_upstream_to_metadata, #validate_at_most_one_upstream_to_metadata, #validate_no_arguments_to_metadata, #validate_no_upstreams_to_metadata, #validate_one_upstream_to_metadata, #validate_required_options_to_metadata, #warn_about_missing_metadata

Constructor Details

This class inherits a constructor from ConceptQL::Operators::Operator

Instance Method Details

#flattened ⇒ Object 



23
24
25
26
27
28
29
30
31
32
33
 
# File 'lib/conceptql/operators/union.rb', line 23

def flattened
  exprs = []
  upstreams.each do |x|
    if x.is_a?(Union)
      exprs.concat x.flattened.upstreams
    else
      exprs << x
    end
  end
  dup_values(exprs)
end

#optimized ⇒ Object 



35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
 
# File 'lib/conceptql/operators/union.rb', line 35

def optimized
  first, *rest = flattened.upstreams
  exprs = [first]

  rest.each do |expression|
    add = true
    exprs.length.times do |i|
      exp = exprs[i]
      if exprs[i].unionable?(expression)
        exprs[i] = exp.union(expression, all: true)
        add = false
        break
      end
    end
    exprs << expression if add
  end

  dup_values(exprs.map{|x| x.is_a?(Operator) ? x.optimized : x})
end

#query(db) ⇒ Object 



15
16
17
18
19
20
21
 
# File 'lib/conceptql/operators/union.rb', line 15

def query(db)
  upstreams.map do |expression|
    expression.evaluate(db).from_self
  end.inject do |q, query|
    q.union(query, all: true)
  end
end