selectOne = async (tbl, where, selectopts = Object.create(null)) => {
  const rows = await select(tbl, where, { ...selectopts, limit: 1 });
  if (rows.length === 0) {
    const w = mkWhere(where);
    throw new Error(`no ${tbl} ${w.where} are ${w.values}`);
  } else return rows[0];
}
Select one record
@param {srting} tbl - table name
@param {object} where - where object
@param {object} [selectopts = {}] - select options
@returns {Promise<object>} return first record from sql result
@throws {Error}