`REL TABLE GROUP`: Error: Binder exception: Create rel with multiple rel labels or bound by multiple node labels is not supported. (hashtag2677)

[vikramsubramanian]

Version: v0.1.0

REL TABLE GROUP seems not equivalent to separately defined RELs.

This errors:

CREATE NODE TABLE V1 (id STRING, PRIMARY KEY(id));
CREATE NODE TABLE V2 (id STRING, PRIMARY KEY (id));
CREATE NODE TABLE V3 (id STRING, PRIMARY KEY (id));
CREATE REL TABLE GROUP MYREL(FROM V3 TO V2, FROM V2 TO V1);

kuzu> CREATE (:V3 {id: "v3"})-[:MYREL]->(:V2 {id: "v2"})-[:MYREL]->(:V1 {id: "v1"});
Error: Binder exception: Create rel  with multiple rel labels or bound by multiple node labels is not supported.

This works:

CREATE NODE TABLE V1 (id STRING, PRIMARY KEY(id));
CREATE NODE TABLE V2 (id STRING, PRIMARY KEY (id));
CREATE NODE TABLE V3 (id STRING, PRIMARY KEY (id));
CREATE REL TABLE RELV2V1(FROM V2 TO V1);
CREATE REL TABLE RELV3V2(FROM V3 TO V2);
CREATE (:V3 {id: "v3"})-[:RELV3V2]->(:V2 {id: "v2"})-[:RELV2V1]->(:V1 {id: "v1"});

)

[mayil-ai[bot]]

Summary: Error occurs when using REL TABLE GROUP with multiple rel labels or bound by multiple node labels in Cypher.

Possible Solution

Based on the provided information, the issue seems to be related to the CREATE REL TABLE GROUP functionality, which does not support creating relationships with multiple labels or relationships that are bound by nodes with multiple labels. To resolve this issue, follow these steps:

• Modify the bindCreateRelTableGroupInfo function in src/binder/bind/bind_ddl.cpp to check for duplicate relationship labels or node labels in the srcDstTablePairs before creating the relationship group.
• If duplicates are detected, throw a BinderException with a clear message indicating that creating a relationship group with multiple identical relationship labels or node labels is not supported.
• Alternatively, if the design allows, adjust the implementation to support multiple labels by handling them appropriately in the CREATE REL TABLE GROUP logic.
• Ensure that the transformCreateRelTableGroup function in src/parser/transform/transform_ddl.cpp correctly parses and transforms the CREATE REL TABLE GROUP statement to handle multiple labels if the design is changed to support them.
• Update the CreateRelTableGroup::executeDDLInternal method in src/include/processor/operator/ddl/create_rel_table_group.h to execute the DDL operation according to the new logic.
• Add unit tests in test/ddl/e2e_ddl_test.cpp to cover cases where multiple labels are used with CREATE REL TABLE GROUP to ensure that the new functionality works as expected or that the appropriate error is thrown if not supported.
• Update documentation and error messages to reflect the changes in functionality or limitations.

Remember to follow the project's coding standards and guidelines for naming, error handling, and testing when making these changes.

Code snippets to check

• src/parser/transform/transform_ddl.cpp

  This snippet contains the transformation logic for creating a REL TABLE GROUP, which is directly related to the issue reported.

• src/binder/bind/bind_updating_clause.cpp

  This snippet contains the binder logic that throws the exception mentioned in the issue when trying to create a relationship with multiple labels or bound by multiple node labels.

• src/binder/bind/bind_ddl.cpp

  This snippet contains the binding logic for creating a REL TABLE GROUP, which may need to be reviewed to ensure that the creation process aligns with the expected behavior.