linkUpdating Nodes and Relationships

Apart from saving an existing Instance, each model provides functions to directly update nodes or relationships.

linkUpdating Nodes

Nodes can be updated directly by providing the properties to be set, providing property update operators, and a where parameter to match the nodes.

1linkawait Users.update(

2link  {

3link    /* --> updates the nodes to set their name to 'Bob' */

4link    name: 'Bob',

5link    /* --> using the "remove" Symbol from "UpdateOp" */

6link    age: { [UpdateOp.remove]: true },

7link  },

8link  {

9link    /* --> (optional) a where parameter to match nodes */

10link    where: {

11link      /* --> nodes with the id '1' will be matched */

12link      id: '1',

13link    },

14link    /* --> (optional) when true, the first element of the returned tuple contains the updated instances */

15link    return: false,

16link    /* --> (optional) an existing session or transaction to use */

17link    session: null,

18link  },

19link);

linkReturn value

The method always returns a tuple [instances, queryResult]:

• instances: Array of updated Instances (populated when return: true, empty when return: false)
• queryResult: The QueryResult from the neo4j driver

1linkconst [instances, queryResult] = await Users.update(

2link  { name: 'Bob' },

3link  {

4link    where: { id: '1' },

5link    return: true,

6link  },

7link);

8link

9link/* --> instances is populated when return: true */

10linkconsole.log(instances[0].name); // "Bob"

11linkconsole.log(queryResult.summary.counters.updates().propertiesSet); // number of properties updated

linkUpdating relationship properties via the Model static

Relationship properties can be updated directly by providing the values to be set, the relationship alias, and an optional where parameter to match the source nodes, target nodes and relationships.

1linkawait Users.updateRelationship(

2link  {

3link    /* --> sets the 'rating' property of the relationship to the following */

4link    rating: 5,

5link  },

6link  {

7link    /* --> used the 'Orders' alias for the relationship configuration, as provided in the Model definition */

8link    alias: 'Orders',

9link    /* --> (optional) where parameters for matching the nodes or the relationship */

10link    where: {

11link      /* --> the source node(s) (User) is matched to have the following name */

12link      source: {

13link        name: 'Bob',

14link      },

15link      /* --> the target node(s) (Order) is matched to have the following id */

16link      target: {

17link        id: '2',

18link      },

19link      /* --> the relationship(s) between the source and the target node(s) are matched to have the following 'rating' */

20link      relationship: {

21link        rating: 4,

22link      },

23link    },

24link    /* --> (optional) when true, the first element of the returned tuple contains the updated relationships */

25link    return: false,

26link    /* --> (optional) throws NeogmaNotFoundError if no relationships were updated */

27link    throwIfNoneUpdated: false,

28link    /* --> (optional) an existing session or transaction to use */

29link    session: null,

30link  },

31link);

linkReturn value

The method always returns a tuple [relationships, queryResult]:

• relationships: Array of { source, target, relationship } objects (populated when return: true, empty when return: false)
• queryResult: The QueryResult from the neo4j driver

1linkconst [relationships, queryResult] = await Users.updateRelationship(

2link  { rating: 5 },

3link  {

4link    alias: 'Orders',

5link    where: { source: { name: 'Bob' } },

6link    return: true,

7link  },

8link);

9link

10link/* --> relationships is populated when return: true */

11linkconsole.log(relationships[0].relationship.rating); // 5

12linkconsole.log(queryResult.summary.counters.updates().propertiesSet); // number of properties updated

linkUpdating relationship properties via the Instance method

Similar to the Model static, relationship properties can be updated directly by providing the values to be set, the relationship alias, and an optional where parameter to match the target nodes and relationships. The source node will always be the one that corresponds to the instance, and its primary key field must be set.

1link/* --> let 'user' be a Users Instance. It's used as the source node */

2linkawait user.updateRelationship(

3link  {

4link    /* --> sets the 'rating' property of the relationship to the following */

5link    rating: 5,

6link  },

7link  {

8link    /* --> used the 'Orders' alias for the relationship configuration, as provided in the Model definition */

9link    alias: 'Orders',

10link    /* --> (optional) where parameters for matching the nodes or the relationship */

11link    where: {

12link      /* --> the target node(s) (Order) is matched to have the following id */

13link      target: {

14link        id: '2',

15link      },

16link      /* --> the relationship(s) between the source and the target node(s) are matched to have the following 'rating' */

17link      relationship: {

18link        rating: 4,

19link      },

20link    },

21link    /* --> (optional) when true, the first element of the returned tuple contains the updated relationships */

22link    return: false,

23link    /* --> (optional) throws NeogmaNotFoundError if no relationships were updated */

24link    throwIfNoneUpdated: false,

25link    /* --> (optional) an existing session or transaction to use */

26link    session: null,

27link  },

28link);

The instance method also returns a tuple [relationships, queryResult]:

1linkconst [relationships, queryResult] = await user.updateRelationship(

2link  { rating: 5 },

3link  {

4link    alias: 'Orders',

5link    where: { target: { id: '2' } },

6link    return: true,

7link  },

8link);

9link

10linkconsole.log(relationships[0].relationship.rating); // 5

11linkconsole.log(queryResult.summary); // query summary