apoc.schema.relationship.constraintExists
Function

This function is not considered safe to run from multiple threads. It is therefore not supported by the parallel runtime. For more information, see the Cypher Manual → Parallel runtime.
Prior to the release of APOC 2025.07, this function was restricted on on-premise instances. To use it on an older version, it must be unrestricted. For more details, see Installation → Load and unrestrict.

Details
Syntax	`apoc.schema.relationship.constraintExists(type, propertyName)`
Description	Returns a `BOOLEAN` depending on whether or not a constraint exists for the given `RELATIONSHIP` type with the given property names.
Arguments	Name	Type	Description
	`type`	`STRING`	The relationship type to check for a constraint on.
	`propertyName`	`LIST<STRING>`	The property names to check for a constraint on.
Returns	`BOOLEAN`

Prior to the release of APOC 2025.07, this procedure was restricted on on-premise instances. To use it on an older version, it must be unrestricted. For more details, see Installation → Load and unrestrict.

Usage Examples

The examples in this section are based on a database that has applied the following constraints:

CREATE CONSTRAINT likesDay
FOR ()-[like:LIKED]-()
REQUIRE (like.day) IS NOT NULL;

RETURN apoc.schema.relationship.constraintExists("LIKED", ["day"]) AS output;

Results
output
TRUE

More documentation of apoc.schema.relationship.constraintExists