Better error message for query with two CREATE statements (hashtag2779)

[vikramsubramanian]

I was trying the following on the RDFGraphs and wrote this query, but I can't understand the error message:

kuzu> WITH " as kz, " as rdf 
..> MATCH (s:UniKG_r {iri: kz+"Nour"})
..> CREATE (s)-[p:UniKG_rt {iri: rdf + "type"}]->(o:UniKG_r {iri: kz + "student"})
..> RETURN *;
Error: Cannot evaluate expression with type PROPERTY.

This is after I create an RDFGraph UniKG and insert the uni.ttl turtle file with the set of triples shown the example database in RDFGraphs documentation.

If I remove the RETURN statement things work.

)

[mayil-ai[bot]]

Summary: Error message is unclear when executing a query with two CREATE statements in RDFGraphs.

Possible Solution

Based on the provided information, the issue seems to be related to the string concatenation within the iri property in the Cypher-like query language used by Kùzu. The error message Error: Cannot evaluate expression with type PROPERTY. suggests that the concatenation operation is not being handled correctly, possibly due to a type mismatch or an incorrect evaluation context.

To resolve the issue:

• Ensure that the WITH clause correctly assigns string literals to the variables kz and rdf. If these are meant to be string literals, they should be enclosed in quotes.
• Verify that the concatenation operation is supported for the iri property within the MATCH and CREATE clauses.
• If the iri property expects a string, ensure that the concatenation operation results in a string type.
• If removing the RETURN statement resolves the issue, it could indicate that the RETURN clause is affecting the evaluation context. Investigate how the RETURN clause interacts with the CREATE clause and whether it affects the evaluation of expressions.
• Check the documentation or implementation details for the WITH, MATCH, CREATE, and RETURN clauses to understand the expected behavior and data types for the iri property.
• If the issue persists, consider consulting the Kùzu documentation or reaching out to the maintainers for guidance on the correct usage of string concatenation within queries.

Please note that the provided Java and C++ test code snippets and the ANTLR parser definitions do not seem to be directly relevant to the issue at hand, as they do not contain the logic for processing the specific query that is causing the error.

Code snippets to check

• tools/java_api/src/test/java/com/kuzudb/test/QueryResultTest.java

  This file contains tests for query results and error messages, which may be relevant for improving error messages for queries.

• third_party/antlr4_cypher/cypher_parser.cpp

  This file contains the Cypher parser implementation, which is likely involved in parsing queries and generating error messages.