DataTable中的问题查找记录 [英] Problem find record in DataTable

问题描述

我有2张桌子:
Order(id，date，idWordker，idCustomer)Primakey键:id
OrderDetail(id，idProduct，quantity，price)Primakey键:id
您可以在OrderDetail中看到2个键.我需要更新数量
我使用:

I have 2 tables:
Order(id,date,idWordker,idCustomer) Primakey key:id
OrderDetail(id,idProduct,quantity,price) Primakey key:id
You can see 2 keys in OrderDetail.I need to update the quantity
I use:

public DataTable AddCart(string id, string idProduct,int quantity,int price)
{
        DataTable tbCart = new DataTable();
        tbCart = (DataTable)HttpContext.Current.Session["Cart"];
        if (tbCart == null)
            tbCart = MakeCart();
        DataRow dr = tbCart.NewRow();
        dv = tbCart.DefaultView;
        dv.Sort = "idProduct";
        rIndex = dv.Find(idProduct);
        if (rIndex != -1)
        {
            //update quantity
        }
        else
        {
                dr[0] = id;
                dr[1] = idProduct;
                dr[2] = 1;//quantity
                dr[3] = price;
        }
}

如果OrderDetail存在idProduct，则产品数量将被更新.Session["Cart"]将被插入OrderDetail
如何用2个键找到?

If OrderDetail exist idProduct,the quantity of product will be updated.Session["Cart"] will be insert into OrderDetail
How to find with 2 keys?

推荐答案

2个键?

其中哪一个是产品的唯一参考点?根据您的数据库设计和使用情况选择并使用唯一的一种.如果两者都是唯一的，请删除一个不需要的键.

2 keys?

Which one of them is a unique reference point for a product? Pick and use the one that is unique based on your DB design and use. If both are unique, remove one key as it''s not needed.

如问题中所述，只有Id 是OrderDetail 中的主键，而idProduct 是另一个id.
因此，我认为DataTable 的Select 方法可用于查找所需的行，如下所示:

As stated in the question only Id is the primary key in OrderDetail and idProduct is another id.
Hence, I think the Select method of DataTable can be used to find the required row as follows:

DataRow[] rows = tbCart.Select(
        string.Format("id='{0}' and idProduct='{1}'",id,idProduct),
        idProduct, DataViewRowState.CurrentRows);
if (rows.Length > 0){
   rows[0]["quantity"]= 
   rows[0]["price"]=
}

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