def does_row_exist(self, table: str, field: str, value: Any) -> bool:
        """Checks for the existence of a record by a single field (typically a
        PK)."""
        sql = ("SELECT COUNT(*) FROM " + self.delimit(table) +
               " WHERE " + self.delimit(field) + "=?")
        row = self.fetchone(sql, value)
        return True if row[0] >= 1 else False