addConstraint: Uniqueness Constraints
In RNeo4j: Neo4j Driver for R

Description Usage Arguments Details See Also Examples

Add a uniqueness constraint to a label and property key.

1	addConstraint(graph, label, key)

`graph`	A graph object.
`label`	A character string.
`key`	A character string.

A uniqueness constraint cannot be added to a (label, key) pair that already has an index applied. Attempting to add a uniqueness constraint where an index already exists results in an error. Use getIndex to view any pre-existing indexes. If you wish to add a uniqueness constraint, use dropIndex to drop the index.

getConstraint, dropConstraint

## Not run: 
graph = startGraph("http://localhost:7474/db/data/")
clear(graph)

addConstraint(graph, "Person", "name")

createNode(graph, "Person", name = "Alice")
createNode(graph, "Person", name = "Bob")
try(createNode(graph, "Person", name = "Alice"))

## End(Not run)