vertexLabel

How to create a vertex label.

Synopsis

schema.vertexLabel('*vertexLabel*').
  [ materializedView('*indexName*'). | secondaryIndex('*indexName*'). | searchIndex('*indexName*'). ]
    [ by('*propertyName*'). ]
    [ waitForIndex(). ]
  [ tableName('*tableName*'). ]
  [fromExistingTable('*tableName*') ]
  [ ifNotExists(). ]
  partitionBy('*propertyName*', *propertyType*). [ ... ]
  [ clusterBy('*propertyName*', *propertyType*). ... ]
  [ property('*propertyName*', *propertyType* [ , static | , ( Desc | Asc )] ). ]
  [ create() | describe() | drop() | ( addProperty | dropProperty )('*propertyName*', *propertyType*).alter() ]

A vertex label specifies a type of vertex that can be stored in DataStax Graph (DSG). A vertex label must have a defined partition key, and can have, in addition, properties, clustering keys, and indexes defined. The partitionBy and clusteringBy are used to specify a vertex id, identifying the partition storage location and order within the partition, respectively.

DataStax Graph limits the number of vertex and edge labels to 200 per graph.

materializedView, secondaryIndex, searchIndex: Set an index for a vertex label.
ifNotExists: Check for lack of current existence with ifNotExists() before creating a new vertex label.
tableName: Specify a table name for the CQL table that holds the vertex label data.
partitionBy: Specify a vertex label partition location. The value consists of one or more properties, with multiple properties forming a composite partition key. Which partition the data will be stored on is defined with this step.
clusteringBy: Specify whether a vertex label can have any clustering columns. The value consists of one or more properties that specify how data will be stored within a partition.
property: Properties can be defined for vertices and edges. Allowed characters for the name are alphabetical or underscore. Properties can also be declared static to correspond to a static CQL table column.
create: Create a vertex label.
describe: Describe a vertex label.
drop: Drop a vertex label.
addProperty.alter, dropProperty.alter: Add or drop a property by altering a previously created vertex label.
fromExistingTable: Convert an existing CQL table into a vertex label.

Examples

Create a vertex label person with a single partitionBy:

schema.vertexLabel('person').
  ifNotExists().
  partitionBy('person_id', Uuid).
  property('name', Text).
  property('gender', Text).
  property('nickname', setOf(Text)).
  property('cal_goal', Int).
  property('macro_goal', listOf(Int)).
  property('country', listOf(tupleOf(Text, Date, Date))).
  property('badge', mapOf(Text, Date)).
  create()

This vertex label is created if it doesn’t already exist, has a single partition person_id, and several properties of varying data types.

Create a vertex label person with a compound partition key, two partitionBy steps:

schema.vertexLabel('meal').
  ifNotExists().
  partitionBy('type', Text).
  partitionBy( 'meal_id', Int).
  create()

Create a vertex label person with a composite primary key, three partitionBy steps and a clusterBy step:

schema.vertexLabel('fridge_sensor').
  ifNotExists().
  partitionBy('state_id', Int).
  partitionBy('city_id', Int).
  partitionBy('zipcode_id', Int).
  clusterBy('sensor_id', Int).
  property('name', Text).
  create()

Create a vertex label shopping_list with a tableName:

schema.vertexLabel('shopping_list').
  tableName('my_shopping').
  ifNotExists().
  partitionBy('shoplist_id', Int).
  create()

The CQL table will be named my_shopping, while the vertex label is shopping_list.

Convert a CQL table into a vertex label:

schema.vertexLabel('recipe').
  fromExistingTable('recipe_table').
  create()

Add a property to a vertex label:

schema.vertexLabel('book').
    addProperty('book_discount', Text).
    alter()

A quick reference to indexes is included here, see indexes for more thorough information.

Create a materialized view index on a vertex label:

schema.vertexLabel('person').
  materializedView('person_by_name').
  ifNotExists().
  partitionBy('name').
  create()

Create a secondary index on a vertex label:

schema.vertexLabel('person').
  secondaryIndex('person_2i_by_nickname').
  ifNotExists().
  by('nickname').
  indexValues().
  create()

Create a search index on a vertex label:

schema.vertexLabel('recipe').
  searchIndex().
  ifNotExists().
  by('instructions').asText().
  by('name').
  by('cuisine').
  waitForIndex(30).
  create()

The waitForIndex step can be added to any index creation, to allow a pause for index building to occur.

Get the schema creation command for all vertex labels using the describe() command:

schema.vertexLabels().describe()

Get the schema creation command for a vertex label using the describe() command:

schema.vertexLabel('person').describe()

Drop a vertex label:

schema.vertexLabel('book').
  ifExists().
  drop()

Drop a property from a vertex label:

schema.vertexLabel('person').
    dropProperty('gender').
    alter()

Drop an index for a vertex label:

schema.vertexLabel('person').
    materializedView('person_by_gender').
    ifExists().
    drop()

Drop an index for a vertex label:

schema.vertexLabel('store').
    searchIndex().
    dropProperty('name').
    alter()

vertexLabel

Synopsis

Description

Examples

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