Add Step 2: SPARQL UPDATE queries to transform literals into objects.

19 queries in updates/ convert categorical columns (continent, country,
city, gender, profession, etc.) from literals to typed RDF objects with
rdfs:label. map/step-02.rb applies them to produce data/graph-02.ttl.
Also fix step-01.rb to sanitize column names with spaces and avoid
prefix serialization issues with fragment IRIs.

README.md

@@ -31,4 +31,83 @@ docker compose up -d
 bundle exec ruby map/step-01.rb
 ```
 
-### Step 2 -
+### Step 2 - Generate Objects
+
+Continents and countries should be objects instead of literals. To this end, we can transform the following data:
+
+```
+base:location\/ARG-BahBlanca-00 a base:location;
+  base:location\#City "Bahia Blanca";
+  base:location\#Continent "South America";
+  base:location\#Country "Argentina";
+  base:location\#GeoNamesID "3865086";
+  base:location\#IDLocation "ARG-BahBlanca-00";
+  base:location\#latitude -3.87253e1;
+  base:location\#longitude -6.22742e1;
+  base:location\#wikidata "Q54108";
+  base:location\#wikipedia "https://en.wikipedia.org/wiki/Bah%C3%ADa_Blanca" .
+```
+
+Into the following data:
+
+```
+base:location\/ARG-BahBlanca-00 a base:location;
+  base:location\#City base:City-BahiaBlanca;
+  base:location\#Continent base:Continent-SouthAmerica;
+  base:location\#Country base:Country-Argentina;
+  base:location\#GeoNamesID "3865086";
+  base:location\#IDLocation "ARG-BahBlanca-00";
+  base:location\#latitude -3.87253e1;
+  base:location\#longitude -6.22742e1;
+  base:location\#wikidata "Q54108";
+  base:location\#wikipedia "https://en.wikipedia.org/wiki/Bah%C3%ADa_Blanca" .
+
+base:City-BahiaBlanca a base:City;
+  rdfs:label "Bahia Blanca"@en .
+
+base:Continent-SouthAmerica a base:Continent;
+  rdfs:label "South America"@en .
+
+base:Country-Argentina a base:Country;
+  rdfs:label "Argentina"@en .
+```
+
+Notice that all ranges of property `rdfs:label` are stated to be in English.
+
+Generate an SPARQL UPDATE query that do this tranformation for all elements of the table and save it a new folder called `updates`. Do the same with the other tables, proposing which columns should be defined as objects. For every table define a different SPARQL UPDATE query and to be saved in the `updates` folder. Enumerate these generated queries adding a prefix number like 001, 002, 003, and so on.
+
+After generating the update queries, generate a Ruby script that executes the updates on the RDF graph generated in the previous step and generates a new RDF graph to be saved: `data/graph-02.ttl`.
+
+#### Summary
+
+19 SPARQL UPDATE queries in `updates/` transform literal values into typed objects across all tables:
+
+| Query | Table | Column | Object type |
+|-------|-------|--------|-------------|
+| 001 | location | Continent | Continent |
+| 002 | location | Country | Country |
+| 003 | location | State | State |
+| 004 | location | City | City |
+| 005 | migration_table | reason | MigrationReason |
+| 006 | migration_table | reason2 | MigrationReason |
+| 007 | organisation | InstType | InstitutionType |
+| 008 | person | gender | Gender |
+| 009 | person | Nametype | Nametype |
+| 010 | person | Importsource | ImportSource |
+| 011 | person_profession | Eprofession | Profession |
+| 012 | personnames | Nametype | Nametype |
+| 013 | relationship | Relationshiptype | RelationshipType |
+| 014 | relationship | relationshiptype_precise | RelationshipTypePrecise |
+| 015 | religions | religion | Religion |
+| 016 | work | Profession | Profession |
+| 017 | work | Profession2 | Profession |
+| 018 | work | Profession3 | Profession |
+| 019 | work | EmploymentType | EmploymentType |
+
+Each query replaces a literal value with an object reference and creates the object with `rdf:type` and `rdfs:label` (in English). The script `map/step-02.rb` loads `data/graph-01.ttl`, applies all queries in order, and writes `data/graph-02.ttl` (164,632 triples).
+
+To run:
+
+```sh
+bundle exec ruby map/step-02.rb
+```

map/step-01.rb

@@ -66,8 +66,12 @@ def row_iri(table, pk_value)
   RDF::URI.new("#{BASE_IRI}#{table}/#{URI.encode_www_form_component(pk_value.to_s)}")
 end
 
+def sanitize_name(name)
+  name.to_s.gsub(/[^a-zA-Z0-9_-]/, '_').gsub(/_+/, '_').gsub(/\A_+|_+\z/, '')
+end
+
 def column_iri(table, column)
-  RDF::URI.new("#{BASE_IRI}#{table}##{column}")
+  RDF::URI.new("#{BASE_IRI}#{table}##{sanitize_name(column)}")
 end
 
 def class_iri(table)
@@ -75,7 +79,7 @@ def class_iri(table)
 end
 
 def ref_iri(table, fk_col)
-  RDF::URI.new("#{BASE_IRI}#{table}#ref-#{fk_col}")
+  RDF::URI.new("#{BASE_IRI}#{table}#ref-#{sanitize_name(fk_col)}")
 end
 
 def to_rdf_literal(value)
@@ -124,11 +128,10 @@ PRIMARY_KEYS.each do |table, pk_col|
   end
 end
 
-output_path = File.expand_path('../graph-01.ttl', __dir__)
+output_path = File.expand_path('../data/graph-01.ttl', __dir__)
 RDF::Turtle::Writer.open(output_path, prefixes: {
-  rdf:  RDF.to_uri,
-  xsd:  RDF::XSD.to_uri,
-  base: RDF::URI.new(BASE_IRI)
+  rdf: RDF.to_uri,
+  xsd: RDF::XSD.to_uri
 }) do |writer|
   graph.each_statement { |stmt| writer << stmt }
 end

map/step-02.rb

@@ -0,0 +1,38 @@
+#!/usr/bin/env ruby
+# frozen_string_literal: true
+
+# Step 2: Transform literal values into RDF objects using SPARQL UPDATE queries
+
+require 'rdf'
+require 'rdf/turtle'
+require 'sparql'
+
+input_path  = File.expand_path('../data/graph-01.ttl', __dir__)
+output_path = File.expand_path('../data/graph-02.ttl', __dir__)
+updates_dir = File.expand_path('../updates', __dir__)
+
+puts "Loading graph from #{input_path}..."
+graph = RDF::Graph.load(input_path)
+puts "Loaded #{graph.count} triples."
+
+Dir.glob(File.join(updates_dir, '*.rq')).sort.each do |query_file|
+  query = File.read(query_file)
+  name  = File.basename(query_file)
+
+  before = graph.count
+  SPARQL.execute(query, graph, update: true)
+  after = graph.count
+  puts "Applied #{name}: #{before} -> #{after} triples (#{after - before >= 0 ? '+' : ''}#{after - before})"
+end
+
+puts "Writing #{graph.count} triples to #{output_path}..."
+RDF::Turtle::Writer.open(output_path, prefixes: {
+  rdf:  RDF.to_uri,
+  rdfs: RDF::RDFS.to_uri,
+  xsd:  RDF::XSD.to_uri,
+  base: RDF::URI.new('http://example.org/migrants/')
+}) do |writer|
+  graph.each_statement { |stmt| writer << stmt }
+end
+
+puts "Done."

updates/001-location-continent.rq

@@ -0,0 +1,16 @@
+
+PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
+
+DELETE {
+  ?s <http://example.org/migrants/location#Continent> ?val .
+}
+INSERT {
+  ?s <http://example.org/migrants/location#Continent> ?obj .
+  ?obj a <http://example.org/migrants/Continent> .
+  ?obj rdfs:label ?label .
+}
+WHERE {
+  ?s <http://example.org/migrants/location#Continent> ?val .
+  BIND(IRI(CONCAT("http://example.org/migrants/Continent-", ENCODE_FOR_URI(REPLACE(?val, " ", "")))) AS ?obj)
+  BIND(STRLANG(STR(?val), "en") AS ?label)
+}

updates/002-location-country.rq

@@ -0,0 +1,16 @@
+
+PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
+
+DELETE {
+  ?s <http://example.org/migrants/location#Country> ?val .
+}
+INSERT {
+  ?s <http://example.org/migrants/location#Country> ?obj .
+  ?obj a <http://example.org/migrants/Country> .
+  ?obj rdfs:label ?label .
+}
+WHERE {
+  ?s <http://example.org/migrants/location#Country> ?val .
+  BIND(IRI(CONCAT("http://example.org/migrants/Country-", ENCODE_FOR_URI(REPLACE(?val, " ", "")))) AS ?obj)
+  BIND(STRLANG(STR(?val), "en") AS ?label)
+}

updates/003-location-state.rq

@@ -0,0 +1,16 @@
+
+PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
+
+DELETE {
+  ?s <http://example.org/migrants/location#State> ?val .
+}
+INSERT {
+  ?s <http://example.org/migrants/location#State> ?obj .
+  ?obj a <http://example.org/migrants/State> .
+  ?obj rdfs:label ?label .
+}
+WHERE {
+  ?s <http://example.org/migrants/location#State> ?val .
+  BIND(IRI(CONCAT("http://example.org/migrants/State-", ENCODE_FOR_URI(REPLACE(?val, " ", "")))) AS ?obj)
+  BIND(STRLANG(STR(?val), "en") AS ?label)
+}

updates/004-location-city.rq

@@ -0,0 +1,16 @@
+
+PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
+
+DELETE {
+  ?s <http://example.org/migrants/location#City> ?val .
+}
+INSERT {
+  ?s <http://example.org/migrants/location#City> ?obj .
+  ?obj a <http://example.org/migrants/City> .
+  ?obj rdfs:label ?label .
+}
+WHERE {
+  ?s <http://example.org/migrants/location#City> ?val .
+  BIND(IRI(CONCAT("http://example.org/migrants/City-", ENCODE_FOR_URI(REPLACE(?val, " ", "")))) AS ?obj)
+  BIND(STRLANG(STR(?val), "en") AS ?label)
+}

updates/005-migration_table-reason.rq

@@ -0,0 +1,16 @@
+
+PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
+
+DELETE {
+  ?s <http://example.org/migrants/migration_table#reason> ?val .
+}
+INSERT {
+  ?s <http://example.org/migrants/migration_table#reason> ?obj .
+  ?obj a <http://example.org/migrants/MigrationReason> .
+  ?obj rdfs:label ?label .
+}
+WHERE {
+  ?s <http://example.org/migrants/migration_table#reason> ?val .
+  BIND(IRI(CONCAT("http://example.org/migrants/MigrationReason-", ENCODE_FOR_URI(REPLACE(?val, " ", "")))) AS ?obj)
+  BIND(STRLANG(STR(?val), "en") AS ?label)
+}

updates/006-migration_table-reason2.rq

@@ -0,0 +1,15 @@
+PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
+
+DELETE {
+  ?s <http://example.org/migrants/migration_table#reason2> ?val .
+}
+INSERT {
+  ?s <http://example.org/migrants/migration_table#reason2> ?obj .
+  ?obj a <http://example.org/migrants/MigrationReason> .
+  ?obj rdfs:label ?label .
+}
+WHERE {
+  ?s <http://example.org/migrants/migration_table#reason2> ?val .
+  BIND(IRI(CONCAT("http://example.org/migrants/MigrationReason-", ENCODE_FOR_URI(REPLACE(?val, " ", "")))) AS ?obj)
+  BIND(STRLANG(STR(?val), "en") AS ?label)
+}

updates/007-organisation-insttype.rq

@@ -0,0 +1,16 @@
+
+PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
+
+DELETE {
+  ?s <http://example.org/migrants/organisation#InstType> ?val .
+}
+INSERT {
+  ?s <http://example.org/migrants/organisation#InstType> ?obj .
+  ?obj a <http://example.org/migrants/InstitutionType> .
+  ?obj rdfs:label ?label .
+}
+WHERE {
+  ?s <http://example.org/migrants/organisation#InstType> ?val .
+  BIND(IRI(CONCAT("http://example.org/migrants/InstitutionType-", ENCODE_FOR_URI(REPLACE(?val, " ", "")))) AS ?obj)
+  BIND(STRLANG(STR(?val), "en") AS ?label)
+}

updates/008-person-gender.rq

@@ -0,0 +1,16 @@
+
+PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
+
+DELETE {
+  ?s <http://example.org/migrants/person#gender> ?val .
+}
+INSERT {
+  ?s <http://example.org/migrants/person#gender> ?obj .
+  ?obj a <http://example.org/migrants/Gender> .
+  ?obj rdfs:label ?label .
+}
+WHERE {
+  ?s <http://example.org/migrants/person#gender> ?val .
+  BIND(IRI(CONCAT("http://example.org/migrants/Gender-", ENCODE_FOR_URI(REPLACE(?val, " ", "")))) AS ?obj)
+  BIND(STRLANG(STR(?val), "en") AS ?label)
+}

updates/009-person-nametype.rq

@@ -0,0 +1,16 @@
+
+PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
+
+DELETE {
+  ?s <http://example.org/migrants/person#Nametype> ?val .
+}
+INSERT {
+  ?s <http://example.org/migrants/person#Nametype> ?obj .
+  ?obj a <http://example.org/migrants/Nametype> .
+  ?obj rdfs:label ?label .
+}
+WHERE {
+  ?s <http://example.org/migrants/person#Nametype> ?val .
+  BIND(IRI(CONCAT("http://example.org/migrants/Nametype-", ENCODE_FOR_URI(REPLACE(?val, " ", "")))) AS ?obj)
+  BIND(STRLANG(STR(?val), "en") AS ?label)
+}

updates/010-person-importsource.rq

@@ -0,0 +1,16 @@
+
+PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
+
+DELETE {
+  ?s <http://example.org/migrants/person#Importsource> ?val .
+}
+INSERT {
+  ?s <http://example.org/migrants/person#Importsource> ?obj .
+  ?obj a <http://example.org/migrants/ImportSource> .
+  ?obj rdfs:label ?label .
+}
+WHERE {
+  ?s <http://example.org/migrants/person#Importsource> ?val .
+  BIND(IRI(CONCAT("http://example.org/migrants/ImportSource-", ENCODE_FOR_URI(REPLACE(?val, " ", "")))) AS ?obj)
+  BIND(STRLANG(STR(?val), "en") AS ?label)
+}

updates/011-person_profession-eprofession.rq

@@ -0,0 +1,16 @@
+
+PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
+
+DELETE {
+  ?s <http://example.org/migrants/person_profession#Eprofession> ?val .
+}
+INSERT {
+  ?s <http://example.org/migrants/person_profession#Eprofession> ?obj .
+  ?obj a <http://example.org/migrants/Profession> .
+  ?obj rdfs:label ?label .
+}
+WHERE {
+  ?s <http://example.org/migrants/person_profession#Eprofession> ?val .
+  BIND(IRI(CONCAT("http://example.org/migrants/Profession-", ENCODE_FOR_URI(REPLACE(?val, " ", "")))) AS ?obj)
+  BIND(STRLANG(STR(?val), "en") AS ?label)
+}

updates/012-personnames-nametype.rq

@@ -0,0 +1,16 @@
+
+PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
+
+DELETE {
+  ?s <http://example.org/migrants/personnames#Nametype> ?val .
+}
+INSERT {
+  ?s <http://example.org/migrants/personnames#Nametype> ?obj .
+  ?obj a <http://example.org/migrants/Nametype> .
+  ?obj rdfs:label ?label .
+}
+WHERE {
+  ?s <http://example.org/migrants/personnames#Nametype> ?val .
+  BIND(IRI(CONCAT("http://example.org/migrants/Nametype-", ENCODE_FOR_URI(REPLACE(?val, " ", "")))) AS ?obj)
+  BIND(STRLANG(STR(?val), "en") AS ?label)
+}

updates/013-relationship-relationshiptype.rq

@@ -0,0 +1,16 @@
+
+PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
+
+DELETE {
+  ?s <http://example.org/migrants/relationship#Relationshiptype> ?val .
+}
+INSERT {
+  ?s <http://example.org/migrants/relationship#Relationshiptype> ?obj .
+  ?obj a <http://example.org/migrants/RelationshipType> .
+  ?obj rdfs:label ?label .
+}
+WHERE {
+  ?s <http://example.org/migrants/relationship#Relationshiptype> ?val .
+  BIND(IRI(CONCAT("http://example.org/migrants/RelationshipType-", ENCODE_FOR_URI(REPLACE(?val, " ", "")))) AS ?obj)
+  BIND(STRLANG(STR(?val), "en") AS ?label)
+}

updates/014-relationship-relationshiptype_precise.rq

@@ -0,0 +1,16 @@
+
+PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
+
+DELETE {
+  ?s <http://example.org/migrants/relationship#relationshiptype_precise> ?val .
+}
+INSERT {
+  ?s <http://example.org/migrants/relationship#relationshiptype_precise> ?obj .
+  ?obj a <http://example.org/migrants/RelationshipTypePrecise> .
+  ?obj rdfs:label ?label .
+}
+WHERE {
+  ?s <http://example.org/migrants/relationship#relationshiptype_precise> ?val .
+  BIND(IRI(CONCAT("http://example.org/migrants/RelationshipTypePrecise-", ENCODE_FOR_URI(REPLACE(?val, " ", "")))) AS ?obj)
+  BIND(STRLANG(STR(?val), "en") AS ?label)
+}

updates/015-religions-religion.rq

@@ -0,0 +1,16 @@
+
+PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
+
+DELETE {
+  ?s <http://example.org/migrants/religions#religion> ?val .
+}
+INSERT {
+  ?s <http://example.org/migrants/religions#religion> ?obj .
+  ?obj a <http://example.org/migrants/Religion> .
+  ?obj rdfs:label ?label .
+}
+WHERE {
+  ?s <http://example.org/migrants/religions#religion> ?val .
+  BIND(IRI(CONCAT("http://example.org/migrants/Religion-", ENCODE_FOR_URI(REPLACE(?val, " ", "")))) AS ?obj)
+  BIND(STRLANG(STR(?val), "en") AS ?label)
+}

updates/016-work-profession.rq

@@ -0,0 +1,16 @@
+
+PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
+
+DELETE {
+  ?s <http://example.org/migrants/work#Profession> ?val .
+}
+INSERT {
+  ?s <http://example.org/migrants/work#Profession> ?obj .
+  ?obj a <http://example.org/migrants/Profession> .
+  ?obj rdfs:label ?label .
+}
+WHERE {
+  ?s <http://example.org/migrants/work#Profession> ?val .
+  BIND(IRI(CONCAT("http://example.org/migrants/Profession-", ENCODE_FOR_URI(REPLACE(?val, " ", "")))) AS ?obj)
+  BIND(STRLANG(STR(?val), "en") AS ?label)
+}

updates/017-work-profession2.rq

@@ -0,0 +1,15 @@
+PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
+
+DELETE {
+  ?s <http://example.org/migrants/work#Profession2> ?val .
+}
+INSERT {
+  ?s <http://example.org/migrants/work#Profession2> ?obj .
+  ?obj a <http://example.org/migrants/Profession> .
+  ?obj rdfs:label ?label .
+}
+WHERE {
+  ?s <http://example.org/migrants/work#Profession2> ?val .
+  BIND(IRI(CONCAT("http://example.org/migrants/Profession-", ENCODE_FOR_URI(REPLACE(?val, " ", "")))) AS ?obj)
+  BIND(STRLANG(STR(?val), "en") AS ?label)
+}

updates/018-work-profession3.rq

@@ -0,0 +1,15 @@
+PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
+
+DELETE {
+  ?s <http://example.org/migrants/work#Profession3> ?val .
+}
+INSERT {
+  ?s <http://example.org/migrants/work#Profession3> ?obj .
+  ?obj a <http://example.org/migrants/Profession> .
+  ?obj rdfs:label ?label .
+}
+WHERE {
+  ?s <http://example.org/migrants/work#Profession3> ?val .
+  BIND(IRI(CONCAT("http://example.org/migrants/Profession-", ENCODE_FOR_URI(REPLACE(?val, " ", "")))) AS ?obj)
+  BIND(STRLANG(STR(?val), "en") AS ?label)
+}

updates/019-work-employmenttype.rq

@@ -0,0 +1,16 @@
+
+PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
+
+DELETE {
+  ?s <http://example.org/migrants/work#EmploymentType> ?val .
+}
+INSERT {
+  ?s <http://example.org/migrants/work#EmploymentType> ?obj .
+  ?obj a <http://example.org/migrants/EmploymentType> .
+  ?obj rdfs:label ?label .
+}
+WHERE {
+  ?s <http://example.org/migrants/work#EmploymentType> ?val .
+  BIND(IRI(CONCAT("http://example.org/migrants/EmploymentType-", ENCODE_FOR_URI(REPLACE(?val, " ", "")))) AS ?obj)
+  BIND(STRLANG(STR(?val), "en") AS ?label)
+}