[WIP] 1 1 relationship for v7

[angrykoala]

Description

Adds back limited support for single-relationship (i.e. 1-* and 1-1) to version 7.

This allow for using @relationship directive in non-list fields:

type Movie @node {
    title: String!
    actor: [Actor!]! @relationship(type: "ACTED_IN", direction: IN, properties: "ActedIn")
    director: Director! @relationship(type: "DIRECTED", direction: IN, properties: "Directed")
}

This was removed in v6 due to inherent limitations on maintaining these constraints which could lead to a inconsistent database that could not be queried by GraphQL.

With this PR It will be possible to model and query the data of single element relationships, with the following constraints:

• If multiple relationships exists, the first one will be returned. The relationship that will be returned will not be guaranteed
• Connections will maintain the many-to-many API, even if it is a single relationship. This is to maintain the relay spec
• Delete mutations will be available for nullable fields
• Create mutations will be available for both, nullable and non-nullable

These rules mean that it is easier to maintain consistency between the GraphQL schema and the underlying data, even if not guaranteed

Future work will be done to add support for more risky operations (mutations on non-nullable fields and update mutations) but data consistency will not be guaranteed at the GraphQL level for these

[changeset-bot]

⚠️ No Changeset found

Latest commit: 7ed3c35

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

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[neo4j-team-graphql]

Performance Report

No Performance Changes

Show Full Table

name	dbHits	old dbHits	time (ms)	old time (ms)	maxRows
aggregations.TopLevelAggregateWithMultipleFields	7936	7936	50	68	1134
aggregations.NestedAggregation	15407	15407	54	95	2174
aggregations.AggregationWithWhere	10833	10833	38	63	2174
aggregations.AggregationWhereWithinNestedRelationships	20097917	20097917	1963	2094	2008534
aggregations.AggregationWhereWithinNestedConnections	20097917	20097917	1933	1984	2008534
aggregations.InterfacesAggregations	8324	8324	76	111	2080
aggregations.InterfacesAggregationsWithTwoFields	13526	13526	100	125	2080
connections.Connection	12951	12951	53	61	2174
connections.NestedConnection	37705	37705	106	142	4516
connections.totalCount	1	1	33	25	1
cypher-directive-mutation.TopLevelMutationDirective	1135	1135	35	40	1134
cypher-directive.TopLevelSortWithCypher	12961	12961	38	49	2174
cypher-directive.TopLevelConnectionSortWithCypher	12961	12961	55	61	2174
cypher-directive.TopLevelSortWithCypherWithNested	13096	13096	52	100	2174
cypher-directive.TopLevelConnectionSortWithCypherWithNested	13096	13096	72	157	2174
cypher-directive.TopLevelSortWithExpensiveCypher	13725	13725	101	115	2174
cypher-directive.TopLevelConnectionSortWithExpensiveCypher	13266	13266	79	102	2174
fulltext.Fulltext	80	80	36	49	16
fulltext.FulltextWithNestedQuery	516	516	57	72	84
fulltext.FulltextWithSort	259	259	35	43	37
1262.NestedConnectionWhere	8703	8703	49	61	2174
187.QueryWhere	8564	8564	30	41	2154
2871.NestedRelationshipFilter	19632	19632	60	62	4395
batch-create.BatchCreate	3600	3600	85	99	600
connect.createAndConnect	4410	4410	50	58	1134
create.SimpleMutation	6	6	28	31	1
delete.SimpleDelete	19401	19401	654	666	1040
delete.NestedDeleteInUpdate	14688	14688	93	133	1179
update.NestedUpdate	10129	10129	53	73	2002
query.SimpleQuery	3121	3121	22	22	1040
query.SimpleQueryWithRelationship	15031	15031	41	45	2174
query.SimpleQueryWithNestedWhere	8713	8713	53	55	2154
query.Nested	3988	3988	58	67	1040
query.OrFilterOnRelationshipsAndNestedFilters	26947	26759	163	227	2031
query.QueryWithNestedIn	14480	14480	47	74	1960
query.DeeplyNestedConnectionWhere	8702	8702	61	93	2174
query.DeeplyNestedWithRelationshipFilters	17357	17357	109	135	1552
query.NestedWithRelationshipSingleFilters	3808	3808	140	212	1134
sorting.SortMultipleTypes	3436	3436	73	87	1040
sorting.SortMultipleTypesWithCypherWithCypher	13321	13321	76	86	2174
sorting.SortOnNestedFields	12951	12951	40	50	2174
sorting.SortDeeplyNestedFields	39785	39785	92	91	4516
sorting.ConnectionWithSort	3271	3271	54	64	1040
unions.SimpleUnionQuery	321	321	45	49	35
unions.SimpleUnionQueryWithMissingFields	293	293	50	61	35
unions.NestedUnion	309975	309975	238	287	33033

Old Schema Generation: 21.035s
Schema Generation: 21.418s
Old Subgraph Schema Generation: 24.945s
Subgraph Schema Generation: 24.544s