使用数据集填充 List<T>？ [关闭]

Question

我有一堂课Book:

public class Book
{
    public int ID;
    public string BookName;
    public List<string> BookImageUrl;
}

我想从返回 ID、BookName 和一本书的多个图像的数据集中填充这个类。

Answer 1

您可以开始思考使用以下代码获取图书列表的方向：

DataSet ds = null;

//populate the dataset ds from SQL Server using ADO .Net

/*
Your database would have two tables:
Books : containing Id, BookName columns -> This will get populated in Tables[0] of dataset
BookImages: containing BookId, BookImageUrl columns -> This will get populated in Tables[1] of dataset

Here BookId column in BookImages table is foreign key referring to Id column in Books table 
             */

//tables[0] contains main attributes of a book e.g. Name, Id etc.
DataTable dataTab = ds.Tables[0];

var bookList = dataTab.AsEnumerable().Select(x => new Book                      {
               ID = int.Parse(x["Id"].ToString()),
               BookName = x["BookName"].ToString(),
             });

/*tables[1] contains detailed attributes of a book e.g. book image Urls
         * */
DataTable imageTab = ds.Tables[1];

foreach (var book in bookList)
{
    book.BookImageUrl = imageTab.AsEnumerable()
                        .Where(x => Convert.ToInt32(x["BookId"]) == book.ID)
                        .Select(x => x["BookImageUrl"].ToString()).ToList();
}