This example is included in the usecase-specs of ActiveOrient.
Thanks for bringing this up
2 =begin
3 BOOKs EXAMPLE
4
5 There are several Books. And there is a Table with Keywords.
6
7 The Keywords are associated to the books, this is realized via an Edge
»has_content«
8
9 Thus
10
11 Book = @r.create_vertex_class :book
12 Word = @r.create_vertex_class :word
13 HC = @r.create_edge_class :has_content
14
15 Books have a title and many edges to Word.
16 Words have items, both properties use automatic indexes
17
18 Book.create_property( :title, type: :string, index: :unique )
19 Word.create_property( :item , type: :string, index: :unique )
20
21 for each word:
22 HC.create_edge from: this_book, to: this_word
23
24 To query which books have a given set of words:
25 for each word this query loads a collection of books
26
27 query = OrientSupport::OrientQuery.new from: Word, projection:
"expand(in('HasContent'))"#
28
29 the query is completed by
30
31 query.where( item: '{given word}' )
32
33 The pieces are tied together in a final query »q«
34
35 q = OrientSupport::OrientQuery.new projection: 'expand( $z )'
36 desired_words = [ 'Land', 'Quartal' ]
37 intersects = Array.new
38
39 desired_words.each_with_index do | word, i |
40 symbol = ( i+97 ).chr # convert 1 ->
'a'
41 q.let symbol => query.where( item: word ) # add
where-statement to let-block
42 intersects << "$#{symbol}" # remember
what is added
43 end
44 q.let "$z = Intersect(#{intersects.join(', ')}) " # add
intersect-statement as last entry to let-block
45 result = Word.query_database q, set_from: false
46
47 The generated Query »q« for two words that should appear in any book:
48
49 select expand( $z ) let $a = ( select expand(in('HasContent')) from
Word where item = 'Land' ), $b = ( select expand(in('HasContent')) from
Word where item = 'Quartal' ), $z = Intersect($a, $b)
50
51 =end
52
53 describe OrientSupport::OrientQuery do
54 before( :all ) do
55 ######################################## ADJUST user+password
###################
56 ActiveOrient::OrientDB.default_server= { user: 'hctw', password:
'hc' }
57 @r = ActiveOrient::OrientDB.new database: 'ArrayTest'
58 TestQuery = @r.open_class "model_query"
59 @record = TestQuery.create
60 end # before
61
62 context "Books Words example" , focus: true do
63 before(:all) do
64 @r.delete_class :book
65 Book = @r.create_vertex_class :book
66 Book.create_property( :title, type: :string, index: :unique )
67 @r.delete_class :word
68 Word = @r.create_vertex_class :word
69 Word.create_property( :item , type: :string, index: :unique )
70 @r.delete_class :has_content
71 HC= @r.create_edge_class :has_content
72
73 end
74 it "check structure" do
75 expect( @r.class_hierachie( base_class: 'V').sort ).to eq
[Book.new.classname, Word.new.classname]
76 expect( @r.class_hierachie( base_class: 'E') ).to eq
[HC.new.classname]
77 end
78
79 it "put test-content" do
80 fill_database = ->(sentence, this_book ) do
81 sentence.split(' ').each do |x|
82 this_word = Word.update_or_create where: { item: x }
83 this_edge = HC.create_edge from: this_book, to: this_word if
this_word.present?
84 end
85 end
86 words = 'Die Geschäfte in der Industrie im wichtigen
US-Bundesstaat New York sind im August so schlecht gelaufen wie seit mehr
als sechs Jahren nicht mehr Der entsprechende Empire-State-Index fiel
überraschend von …plus Punkten im Juli auf minus 14,92 Zähler Dies
teilte die New Yorker Notenbank Fed heut mit Bei Werten im positiven
Bereich signalisiert das Barometer ein Wachstum Ökonomen hatten eigentlich
mit einem Anstieg auf 5,0 …Punkte gerechnet'
87 this_book = Book.create title: 'first'
88 fill_database[ words, this_book ]
89 expect( Word.count ).to be > 10
90
91 words2 = 'Das Bruttoinlandsprodukt BIP in Japan ist im zweiten
Quartal mit einer aufs Jahr hochgerechneten Rate von Prozent geschrumpft Zu
Jahresbeginn war die nach den USA und China drittgrößte Volkswirtschaft der
…Welt noch um Prozent gewachsen Der Schwächeanfall wird auch als
Rückschlag für Ministerpräsident Shinzo Abe gewertet der das Land mit einem
Mix aus billigem Geld und Konjunkturprogramm aus der Flaute bringen will
…Allerdings wirkte sich die heutige Veröffentlichung auf die
Märkten nur wenig aus da Ökonomen mit einem schwächeren zweiten Quartal
gerechnet hatten'
92 this_book = Book.create title: 'second'
93 fill_database[ words2, this_book ]
94 expect( Word.count ).to be > 100
95 end
96 it "Query Initialisation" do
97 # search all books with words "Quartal" or "Landereien"
98 query = OrientSupport::OrientQuery.new where:
"out('HasContent').item IN ['Quartal','Landereien']",
99 from: Book
100 result= Book.query_database query
101 expect( result).to be_a Array
102 expect( result).to have_at_least(1).item
103 queried_book = result.first
104 expect( queried_book ).to be_a ActiveOrient::Model::Book
105 expect( queried_book.title ).to eq 'second'
106
107 end
108 it "Subquery Initialisation" do
109 # search for books wiht contain all given words
110 query = OrientSupport::OrientQuery.new from: Word, projection:
"expand(in('HasContent'))"
111
112 q = OrientSupport::OrientQuery.new projection: 'expand( $z )'
113 intersects = Array.new
114 desired_words = [ 'Land', 'Quartal']
115 desired_words.each_with_index do | word, i |
116 symbol = ( i+97 ).chr # convert 1 -> 'a'
117 q.let symbol => query.where( item: word )
118 intersects << "$#{symbol}"
119 end
120 q.let "$z = Intersect(#{intersects.join(', ')}) "
121 puts "generated Query:"
122 puts q.to_s
123 result = Word.query_database q, set_from: false
124 expect( result.pop ).to be_a ActiveOrient::Model::Book
125 end
126
127 end
128 end # describe
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