Multiple cardinality property

How to set a property or an edge for multiple cardinality.

Multiple cardinality property

• Create schema for a multiple cardinality property item_mult and create two vertices, each of which has two items listed for the defined property:

  schema.propertyKey('item_mult').Text().multiple().ifNotExists().create()
  schema.vertexLabel('fridgeItem_multiple').properties('item_mult').ifNotExists().create()
  graph.addVertex(label,'fridgeItem_multiple','name', 'item1','item_mult', ['cheese', 'cheddar cheese'])
  graph.addVertex(label, 'fridgeItem_multiple','name', 'item2', 'item_mult',['yogurt','Greek yogurt'], 'item_mult', ['key lime yogurt'])
  g.V().hasLabel('fridgeItem_multiple').valueMap()

  Because item_mult is defined with multiple cardinality, any number of key value insertions can be made, even using two lists to insert the values. Note that all values are stored in a single list.

  ==>{item_mult=[cheddar cheese, cheese], name=[item1]}
  ==>{item_mult=[Greek yogurt, key lime yogurt, yogurt], name=[item2]}

• Explore the inserted data further:

  g.V().has('fridgeItem_multiple', 'name', 'item2').values('item_mult')

  ==>Greek yogurt
  ==>key lime yogurt
  ==>yogurt

  This output makes it clear that each entry in the list is a separately stored value.
• Check for a single list item, specifying a particular value:

  g.V().hasLabel('fridgeItem_multiple').has('item_mult', 'Greek yogurt').valueMap()
  

  ==>{item_mult=[Greek yogurt, key lime yogurt, yogurt], name=[item2]}

Multiple cardinality edge

• Create schema for a multiple cardinality edge:

  // SCHEMA
  // PROPERTIES
  schema.propertyKey('author').Text().single().create()
  schema.propertyKey('city').Text().single().create()
  schema.propertyKey('dateStart').Text().single().create()
  schema.propertyKey('dateEnd').Text().single().create()
  // VERTEX LABELS
  schema.vertexLabel('author').properties('author').create()
  schema.vertexLabel('city').properties('city').create()
  // EDGE LABELS
  schema.edgeLabel('livedIn').multiple().connection('author','city').create()
  schema.edgeLabel('livedIn').properties('dateStart', 'dateEnd').add()
  // INDEXES
  schema.vertexLabel('author').index('byAuthor').materialized().by('author').add()
  schema.vertexLabel('city').index('byCity').materialized().by('city').add()
  schema.vertexLabel('author').index('byStartDate').outE('livedIn').by('dateStart').add()

  Note that the edge label livedIn is defined with multi-cardinality. The sample data loaded with graphloader is:

  author|city|dateStart|dateEnd
  Julia Child|Paris|1961-01-01|1967-02-10
  Julia Child|New York|1970-06-06|1971-09-23
  Julia Child|Chicago|1980-04-05|1981-01-01
  Julia Child|Paris|1990-01-01|1991-01-01
  Simone Beck|Paris|1960-01-01|1962-09-23

  This data includes two different periods of time in which Julia Child lived in Paris (fictiously), and edges will be multiple because of the multi-cardinality.
  With this data loaded, the resulting graph shows the multi-cardinal edges exist: