实体框架6插入相关实体

有几个实体：操作、批次和销售价格。我想添加一个新的操作，新的批次和新的价格。

 Batch newBatch = new Batch
            {
                Product = product,
                Product_Code = product.Code,
                Purchase = Helper.ConvertAndRound(Purchase.Text),
                Quantity = Helper.ConvertAndRound(Quantity.Text),
                Create_Time = now
            };         
Sale_Price sale_Price = new Sale_Price
            {
                Sale = Helper.ConvertAndRound(Sale.Text),
                Product = product,
                Product_Code = product.Code,
                Start_Date = now,
                End_Date = null
            };
operation = new Operation
            {
                Batch = newBatch,
                Sale_Price = sale_Price,
                Quantity = Helper.ConvertAndRound(Quantity.Text),
                Discount = 0
            };

添加到数据库：

 myContext.Operations.AddRange(operations);                        
 myContext.SaveChanges();

添加了所有实体，但未建立链接（操作 Batch_id = null 和 sale_price = null）。设置链接似乎是正确的，因为如果数据库中有链接，那么它会加载它们。

如果你用拐杖放下身份证，那么一切正常：

myContext.Operations.AddRange(operations);                 
myContext.SaveChanges();
foreach (Operation operation in operations)
{
        operation.Batch_Id = operation.Batch.Id;
        operation.Sale_Price_Id = operation.Sale_Price.Id;
}
myContext.SaveChanges();