Too many mandatory fields for relationships in the import tool's doc

[szarnyasg]

While working on neo4j-contrib/neo4j-apoc-procedures#489, I stumbled upon an inaccuracy in the import tool's documentation. In particular, it states that there are three mandatory fields for relationships, including :TYPE:

https://github.com/neo4j/neo4j-documentation/blob/a5ea8152c40fa5359278ea61a86935b2d63afc29/import-tool/src/docs/ops/import-tool.asciidoc#relationships

For relationship data sources, there are three mandatory fields:

TYPE::
  The relationship type to use for the relationship.
START_ID::
  The id of the start node of the relationship to create.
END_ID::
  The id of the end node of the relationship to create.

However, this is not the case: the :START_ID and :END_ID fields are indeed mandatory, but :TYPE is not as it can be (and usually is) specified with the --relationships:RelType filename.csv switch.

Here are two working examples that load relationships files that do not contain the :TYPE field:

• The Train Benchmark's Neo4j driver uses the neo4j-admin import command: https://github.com/FTSRG/trainbenchmark/blob/1bc29cb878d59b67d59a3367c8a96c873b75ff4b/trainbenchmark-tool-neo4j/src/main/java/hu/bme/mit/trainbenchmark/benchmark/neo4j/driver/Neo4jDriver.java#L144-L161
• The LDBC Social Network Benchmark's load script uses the neo4j-import command: https://github.com/ldbc/ldbc_snb_implementations/blob/e7aff8b6403db4412ce849369d0b6be9dc9d7338/cypher/load-scripts/import-to-neo4j.sh

[mariascharin]

@szarnyasg Thank you for noticing and letting us know! I have fixed this at the source (which is in a different repository). The web version will be updated at the next docs deployment.

Maria