googleapis/mcp-toolbox · error

unable to execute query: %w

Error message

unable to execute query: %w

What it means

YugabyteDB Source.RunSQL executes the statement via the pool's Query; if pgx returns an error issuing the query (SQL syntax error, missing relation, permission denied, cancelled context, connection dropped mid-query), it is wrapped as 'unable to execute query: %w'. The pool connected fine; the failure is at query execution time.

Source

Thrown at internal/sources/yugabytedb/yugabytedb.go:110

	return false
}

func (s *Source) SourceType() string {
	return SourceType
}

func (s *Source) ToConfig() sources.SourceConfig {
	return s.Config
}

func (s *Source) YugabyteDBPool() *pgxpool.Pool {
	return s.Pool
}

func (s *Source) RunSQL(ctx context.Context, statement string, params []any) (any, error) {
	results, err := s.YugabyteDBPool().Query(ctx, statement, params...)
	if err != nil {
		return nil, fmt.Errorf("unable to execute query: %w", err)
	}

	fields := results.FieldDescriptions()

	out := []any{}
	for results.Next() {
		v, err := results.Values()
		if err != nil {
			return nil, fmt.Errorf("unable to parse row: %w", err)
		}
		vMap := make(map[string]any)
		for i, f := range fields {
			val := sources.NormalizeValue(v[i], f.DataTypeOID)
			vMap[f.Name] = val
		}
		out = append(out, vMap)
	}

View on GitHub (pinned to 8cc6e09de2)

Solutions

1. Fix the SQL syntax and verify table/column names exist in the target database
2. Check the database user has privileges for the operation (SELECT/INSERT/etc.)
3. Ensure the number and types of parameters match the placeholders in the statement
4. Test the statement directly with 'ysqlsh' or 'psql' to see the raw server error
5. Read the wrapped '%w' cause for the exact Postgres error code

Example fix

// before
SELECT * FROM order WHERE id = $1
// after (orders table, correct name)
SELECT * FROM orders WHERE id = $1

// Basic client-side checks before invoking the tool
if (typeof statement !== "string" || statement.trim() === "")
  throw new Error("statement must be a non-empty SQL string");
if (statement.includes("order ")) console.warn("verify table names exist in the database");

try {
  const result = await runYugabyteSQL(statement, params);
} catch (err) {
  const cause = err.cause ?? err;
  if (/syntax error|does not exist|permission denied/i.test(String(cause))) {
    console.error("SQL failed server-side:", cause.message);
    // fix statement or permissions, then retry once
  }
  throw err;
}

When it happens

Trigger: RunSQL invoked with a statement that fails server-side: syntax error, referencing a nonexistent table/column, insufficient privileges, parameter count/type mismatch, statement timeout, or context cancellation while running.

Common situations: LLM agent generating invalid SQL against Yugabyte schemas; querying tables that don't exist in the configured database; read-only user attempting writes; long queries hitting timeouts; parameter placeholders count not matching provided params.

Related errors

• unable to execute query: %w
• unable to parse row: %w
• unable to execute query: %w
• unable to execute query: %w
• unable to parse row: %w

AI-assisted analysis of googleapis/mcp-toolbox@8cc6e09de2 (2026-09-05). Data as JSON: /api/errors/bc1d7438c7378894. Report an issue: GitHub.