Class: G2R::RDBMS::Database

Inherits:
Object
  • Object
show all
Defined in:
lib/graph2relational/rdbms-database.rb

Overview

The target RDBMS database that will have the schema and data generated for. It is the target of the conversion.

Instance Method Summary collapse

Constructor Details

#initialize(connection_options, app_options = {}) ⇒ Database

INITIALIZATION



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# File 'lib/graph2relational/rdbms-database.rb', line 10

def initialize(connection_options, app_options = {})
  # services

  @options = app_options
  @conn = Connection.new(connection_options)

  # data

  reset_data()
end

Instance Method Details

#base_tables ⇒ Object

TABLES

Get all the base tables that will be generated. They are based on the Neo4J labels. Columns are based on the Neo4J node attributes.



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# File 'lib/graph2relational/rdbms-database.rb', line 69

def base_tables
  # lazy initialization

  if @base_tables.nil?
    @base_tables = @source.labels.map do |label|

      # if excluding label, do not transform into base table

      next if exclude_label? label

      # generate table

      table = Table.new(label)

      # generate primary key

      table.add_columns(Column.new('id').primary_key)

      # generate schema columns

      columns = @source.label_attributes(label).map {|attribute| Column.new(attribute)}
      table.add_columns(columns)

      # add forced columns

      if @options.has_key? :additional_base_columns
        forced_columns = @options[:additional_base_columns].map {|name| Column.new(name)}
        table.add_columns(forced_columns)
      end

      # generate data

      label_data = @source.label_data(label)
      table.add_data(label_data)

      # generated table

      table
    end.compact
  end

  @base_tables.compact
end

#convert ⇒ Object

Export the schema creation and data import scripts to the specified location



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# File 'lib/graph2relational/rdbms-database.rb', line 31

def convert
  # prepare

  reset_data()

  # create tables

  puts "Creating base tables schema"
  base_tables.each do |table|
    @conn.create_table(table)
  end

  puts "Creating relationship tables schema"
  relationship_tables.each do |table|
    @conn.create_table(table)
  end

  # insert data

  puts "Inserting base tables data"
  base_tables.each do |table|
    @conn.insert_data(table)
  end

  puts "Inserting relationship tables data"
  relationship_tables.each do |table|
    @conn.insert_data(table)
  end
end

#exclude_label?(label) ⇒ Boolean

Check if a label should be excluded and not be transformed into a table

Returns:

  • (Boolean) 


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# File 'lib/graph2relational/rdbms-database.rb', line 153

def exclude_label?(label)
  @options.has_key? :exclude_labels and @options[:exclude_labels].include? label
end

#exclude_relationship?(relationship) ⇒ Boolean

Check if a relationship should be excluded and not be transformed into a relationship table

Returns:

  • (Boolean) 


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# File 'lib/graph2relational/rdbms-database.rb', line 158

def exclude_relationship?(relationship)
  @options.has_key? :exclude_relationships and @options[:exclude_relationships].include? relationship
end

#relationship_tables ⇒ Object

Get all the relationships tables that will be generated. They are based in the found Neo4J relationships. Columss are based on the Neo4J relationship attributes.



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# File 'lib/graph2relational/rdbms-database.rb', line 107

def relationship_tables
  # lazy initialization

  if @relationship_tables.nil?
    @relationship_tables = @source.labels.flat_map do |label|

      # if excluding label, do not transform into relationship table

      next if exclude_label? label

      @source.label_relationships(label).map do |relationship|
        relationship, target_label = relationship

        # if excluding label, do not transform into relationship table

        next if exclude_relationship? relationship
        next if exclude_label? target_label

        # gerarate table

        table = JoinTable.new(label, relationship, target_label)

        # generate columns

        columns = @source.relationship_attributes(label, relationship, target_label).map {|attribute| Column.new(attribute)}
        table.add_columns(columns)

        # add forced columns

        if @options.has_key? :additional_relationship_columns
          forced_columns = @options[:additional_relationship_columns].map {|name| Column.new(name)}
          table.add_columns(forced_columns)
        end

        # generate data

        relationship_data = @source.relationship_data(label, relationship, target_label)
        table.add_data(relationship_data)

        # generated table

        table
      end
    end.compact
  end

  @relationship_tables
end

#reset_data ⇒ Object

Reset the saved data to perform a new conversion



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# File 'lib/graph2relational/rdbms-database.rb', line 59

def reset_data
  @base_tables = nil
  @relationship_tables = nil
end

#source ⇒ Object 



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# File 'lib/graph2relational/rdbms-database.rb', line 26

def source
  @source
end

#source=(source) ⇒ Object

CONVERSION



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# File 'lib/graph2relational/rdbms-database.rb', line 22

def source=(source)
  @source = source
end