Graph query language

Let’s say we want to build graph database, similar to relational database. Then we need language similar to SQL. SQL consists of several sections:

• data query language (DQL)
  • SELECT and co: FROM, WHERE, GROUP BY, ORDER…
• data definition language (DDL aka schema)
  • CREATE, DROP, TRUNCATE, ALTER
• data manipulation language (DML)
  • INSERT, UPDATE, DELETE…
• data control language (DCL)
  • GRANT, DENY, REVOKE
• Transaction Control Language (TCL)
  • COMMIT, ROLLBACK…

Existing languages

See https://www.gqlstandards.org/existing-languages.

There are already a lot of proposals for graph query languages, most known are:

• SPARQL - RDF Query Language
• openCypher - open query language for property graph databases.
• Gremlin is a graph traversal language
• GraphQL

And less known languages:

• DQL based on GraphQL
• PGQL Property Graph Query Language
  • SQL/PGQ
• GQL
• nGQL
• AQL
• PartiQL
• GSQL
  • https://github.com/tigergraph/gsql-graph-algorithms
• TypeQL
• EdgeQL​
• WOQL a datalog variant
• GraphBLAS
  • https://lagraph.readthedocs.io/en/latest/algorithms.html
  • https://github.com/python-graphblas/graphblas-algorithms?tab=readme-ov-file#Plugin-Algorithms
  • https://github.com/GraphBLAS/GraphBLAS-Pointers?tab=readme-ov-file#algorithms

Science papers

This is active research area, there are a lot of papers. See Graph query language papers.

DDL

aka metadata, types, data models, schemas

• https://www.edgedb.com/docs/datamodel/index
• https://typedb.com/docs/typedb/2.x/fundamentals/types
• https://graphql.org/learn/schema/
• Schema Validation and Evolution for Graph Databases
• https://opencypher.org/references/#pgm
• https://docs.tigergraph.com/gsql-ref/current/tutorials/gsql-101/define-a-schema
• https://docs.janusgraph.org/schema/

RDF “schemas”:

• Validating RDF Data
  • SHACL
  • SHEX