# 汇率创建
ns = {
    'id': getID(),
    'from_currency': params_kw.get('from_currency', ''),
    'to_currency': params_kw.get('to_currency', ''),
    'buy_rate': params_kw.get('buy_rate', 0),
    'sell_rate': params_kw.get('sell_rate', 0),
    'mid_rate': params_kw.get('mid_rate', 0),
    'effective_date': params_kw.get('effective_date', curDateString()),
    'updated_at': timestampstr(),
}
if not ns['from_currency'] or not ns['to_currency']:
    return json.dumps({'success': False, 'message': 'from_currency and to_currency required'})
async with get_sor_context(request._run_ns, 'accounting') as sor:
    await sor.C('exchange_rate', ns)
    return json.dumps({'success': True, 'message': '汇率已创建'})