cocoindex-io/cocoindex · error

build_relationship_index_drop requires at least one field

Error message

build_relationship_index_drop requires at least one field

What it means

Input guard in the FalkorDB Cypher builder mirroring its create counterpart: DROP INDEX requires at least one indexed property, and an empty fields list would yield invalid Cypher. Fired when the connector tears down or rebuilds a relationship index but the stored/declared field list is empty. Provide at least one field when declaring the relationship index.

Source

Thrown at python/cocoindex/connectors/falkordb/_cypher.py:169

    """``DROP INDEX FOR (e:`Label`) ON (e.`f1`, ...)``."""
    if not fields:
        raise ValueError("build_node_index_drop requires at least one field")
    field_list = ", ".join(f"e.{_quote(f)}" for f in fields)
    return f"DROP INDEX FOR (e:{_quote(label)}) ON ({field_list})"


def build_relationship_index_create(rel_type: str, fields: Sequence[str]) -> str:
    """``CREATE INDEX FOR ()-[e:`RelType`]-() ON (e.`f1`, ...)``."""
    if not fields:
        raise ValueError("build_relationship_index_create requires at least one field")
    field_list = ", ".join(f"e.{_quote(f)}" for f in fields)
    return f"CREATE INDEX FOR ()-[e:{_quote(rel_type)}]-() ON ({field_list})"


def build_relationship_index_drop(rel_type: str, fields: Sequence[str]) -> str:
    """``DROP INDEX FOR ()-[e:`RelType`]-() ON (e.`f1`, ...)``."""
    if not fields:
        raise ValueError("build_relationship_index_drop requires at least one field")
    field_list = ", ".join(f"e.{_quote(f)}" for f in fields)
    return f"DROP INDEX FOR ()-[e:{_quote(rel_type)}]-() ON ({field_list})"


def build_vector_index_create(
    label: str,
    field: str,
    dimension: int,
    metric: str,
) -> str:
    """``CREATE VECTOR INDEX FOR (e:`Label`) ON (e.`field`) OPTIONS {...}``.

    ``metric`` is the FalkorDB-side ``similarityFunction`` value
    (e.g. ``"cosine"``, ``"euclidean"``). Caller is responsible for translating
    user-facing names into the FalkorDB vocabulary before invoking.
    """
    if dimension <= 0:
        raise ValueError(f"Invalid vector dimension: {dimension}")

View on GitHub (pinned to e84aa99b32)

Solutions

1. Pass exactly the fields the relationship index was created with.
2. Guard the drop call: only issue it when recorded fields are non-empty.
3. Fix the metadata source so relationship index fields survive across runs.

Example fix

// before
build_relationship_index_drop(rel_type="WORKS_AT", fields=[])
// after
build_relationship_index_drop(rel_type="WORKS_AT", fields=["since"])

if fields:
    cypher = build_relationship_index_drop(rel_type, fields)
# else: nothing to drop

def droppable(fields: object) -> bool:
    return isinstance(fields, (list, tuple)) and len(fields) > 0

try:
    cypher = build_relationship_index_drop(rel_type, fields)
except ValueError as e:
    logger.warning('no fields recorded for relationship index %s; skipping drop: %s', rel_type, e)
    cypher = None

When it happens

Trigger: Calling build_relationship_index_drop(rel_type, fields=[]) — dropping a relationship index whose field list is empty or lost.

Common situations: Teardown/cleanup passing empty fields; index metadata not persisted so the drop spec is empty; mismatch between create and drop field lists.

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

• build_relationship_index_create requires at least one field
• build_relationship_upsert requires PK fields for from, to, a
• build_relationship_delete requires at least one primary key
• build_node_index_create requires at least one field
• build_node_index_drop requires at least one field

AI-assisted analysis of cocoindex-io/cocoindex@e84aa99b32 (2026-09-08). Data as JSON: /api/errors/82abfcceb8b50535. Report an issue: GitHub.