apache/superset · error · QueryObjectValidationError

Fetch values predicate failed SQL validation: %(msg)s

Error message

Fetch values predicate failed SQL validation: %(msg)s

What it means

QueryObjectValidationError raised in SqlaTable.get_fetch_values_predicate (models.py:1821) when the fetch_values_predicate SQL fails stored-expression validation (validate_stored_expression → SupersetSecurityException) or query clause validation (QueryClauseValidationException). The predicate is Jinja-rendered, then re-checked with the same sqlglot parser policy as column/metric expressions; if the rendered text is not a valid single expression, the query is aborted.

Source

Thrown at superset/connectors/sqla/models.py:1821

        fetch_values_predicate = self.fetch_values_predicate
        if template_processor:
            fetch_values_predicate = template_processor.process_template(
                fetch_values_predicate
            )
        try:
            # Re-validate the rendered predicate with the same parser policy
            # as stored column and metric expressions before embedding it.
            validate_stored_expression(
                self.database, self.catalog, self.schema, fetch_values_predicate
            )
            return self.text(fetch_values_predicate)
        except (SupersetSecurityException, QueryClauseValidationException) as ex:
            message = (
                ex.error.message
                if isinstance(ex, SupersetSecurityException)
                else ex.message
            )
            raise QueryObjectValidationError(
                _(
                    "Fetch values predicate failed SQL validation: %(msg)s",
                    msg=message,
                )
            ) from ex
        except (TemplateError, SupersetSyntaxErrorException) as ex:
            msg = getattr(ex, "message", str(ex))
            raise QueryObjectValidationError(
                _(
                    "Error in jinja expression in fetch values predicate: %(msg)s",
                    msg=msg,
                )
            ) from ex

    def get_template_processor(self, **kwargs: Any) -> BaseTemplateProcessor:
        return get_template_processor(table=self, database=self.database, **kwargs)

    def get_sqla_table(self) -> TableClause:

View on GitHub (pinned to f4587218dd)

Solutions

  1. Edit the dataset and make fetch_values_predicate a single valid SQL expression (no leading WHERE, no UNION; e.g. "country = 'US'").
  2. Guard Jinja so it always renders to valid SQL in all contexts (|default chains).
  3. Check the embedded %(msg)s from the wrapped SupersetSecurityException/QueryClauseValidationException for the parser's reason.
  4. Temporarily clear the predicate to confirm it is the source, then re-add incrementally.

Example fix

-- before (fetch_values_predicate)
WHERE country = '{{ filter_values('country')[0] }}'

-- after
country = '{{ filter_values('country') | default(['US'], true) | first }}'
Defensive patterns

Strategy: validation

Validate before calling

from sqlglot import parse_one
from sqlglot.errors import ParseError

def fetch_values_predicate_valid(predicate: str) -> bool:
    rendered_guarded = predicate  # assume Jinja guarded upstream
    try:
        parse_one(f"SELECT {rendered_guarded}")
        return True
    except ParseError:
        return False

Try / catch

from superset.exceptions import QueryObjectValidationError

try:
    predicate = table.get_fetch_values_predicate(template_processor=processor)
except QueryObjectValidationError as ex:
    if "Fetch values predicate failed SQL validation" in str(ex):
        log_dataset_config_error(table.id, ex)
    raise

Prevention

When it happens

Trigger: Setting a fetch_values_predicate on a dataset whose SQL (after Jinja rendering) does not parse as a single SQL expression — e.g. renders to an empty string, contains a set operation, or has engine-invalid syntax — and then querying a chart that uses fetch values filtering.

Common situations: fetch_values_predicate with Jinja that renders empty when its filter is absent; predicate valid in one engine but queried under another; pasting a full WHERE clause (with the WHERE keyword) or multi-statement text into the field.

Related errors

AI-assisted analysis of apache/superset@f4587218dd (2026-08-14). Data as JSON: /api/errors/b7c918fb8443fd15. Report an issue: GitHub.