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25 lut 2017 · To create a Node Key ensuring that all nodes with a particular label have a set of defined properties whose combined value is unique, and where all properties in the set are present. Example Query. As of now, neo4j (v3.0.3) still does not support unique constraint with multiple properties.
Single property uniqueness constraints are created with the following commands: Node property uniqueness constraints: CREATE CONSTRAINT constraint_name FOR (n:Label) REQUIRE n.property IS UNIQUE. Relationship property uniqueness constraints: CREATE CONSTRAINT constraint_name FOR ()- [r:REL_TYPE]- () REQUIRE r.property IS UNIQUE. Introduced in 5.7.
Neo4j offers several constraints to ensure the quality and integrity of data in a graph. The following constraints are available in Neo4j: Property uniqueness constraints ensure that the combined property values are unique for all nodes with a specific label or all relationships with a specific type.
To create a uniqueness constraint in Neo4j, use the CREATE CONSTRAINT ON statement. Like this: In the above example, we create a uniqueness constraint on the Name property of all nodes with the Artist label. When the statement succeeds,the following message is displayed: When you create a constraint, Neo4j will create an index.
Here is the syntax for creating a uniqueness constraint for a set of properties: FOR (x: <node_label>) This constraint ensures that a set of values for a node’s properties will be unique. Execute this code to create a uniqueness constraint for the Movie.released and Movie.title properties: FOR (x: Movie)
You add a uniqueness constraint to the graph by creating a constraint that asserts that a particular node property is unique in the graph for a particular type of node. Here is an example for ensuring that the title for a node of type Movie is unique:
Neo4j - Create Unique Constraint - In Neo4j database, CQL CREATE command always creates a new node or relationship which means even though you use the same values, it inserts a new row. As per our application requirements for some nodes or relationships, we have to avoid this duplication.
