如何修复:实体创建销售订单时的"INVALID_FLD_VALUE“

class SalesOrder:
    def __init__(self, customer_name, order_date, quantity, available_stock):
        self.customer_name = customer_name
        self.order_date = order_date
        self.quantity = quantity
        self.available_stock = available_stock

    def validate(self):
        if not self.customer_name or not self.order_date:
            raise ValueError("Customer name and order date are required.")
        
        if not re.match(r'^\d{4}-\d{2}-\d{2}$', self.order_date):
            raise ValueError("Invalid date format. Expected YYYY-MM-DD.")
        
        if self.quantity > self.available_stock:
            raise ValueError("Order quantity exceeds available stock.")
        
        self.customer_name = re.sub(r'[^\w\s]', '', self.customer_name)

# 使用示例
try:
    order = SalesOrder("John Doe", "2023-10-01", 10, 5)
    order.validate()
except ValueError as e:
    print(f"Validation Error: {e}")