将集合值和数据库中的返回值进行比较
本文关键字:返回值 比较 集合 数据库 | 更新日期: 2023-09-27 18:19:39
我有以下类:
public class players
{
public void LottoDraw(object sender, EventArgs e)
{
var connectionstring = "Server=C;Database=lotto;User Id=lottoadmin;Password=password;";
using (var con = new SqlConnection(connectionstring)) // Create connection with automatic disposal
{
con.Open();
// Create new DataTable
DataTable player = new DataTable();
{
// Create new DataAdapter
using (SqlDataAdapter a = new SqlDataAdapter("SELECT TOP 1 LOTTOID, VAL0, VAL1, VAL2, VAL3, VAL4, VAL5 FROM tblLotto ORDER BY NEWID()", con))
{
// Use DataAdapter to fill DataTable
a.Fill(player);
}
}
}
}
public int val0, val1, val2, val3, val4, val5, val6;
public IEnumerable<int> Numbers
{
get
{
return new[] { val0, val1, val2, val3, val4, val5, val6 };
}
}
}
}
它将从数据库中返回一个带有一些乐透号码的随机行。然后,这些值将被放入一个集合中。
然后我想用一些林克来比较获胜的数字和所画的数字。
public void LottoWinners(object sender, EventArgs e)
{
Dictionary<int, int> number = new Dictionary<int, int>();
Random generator = new Random();
while (number.Count < 1)
{
number[generator.Next(1, 49)] = 1;
}
string[] lotto = number.Keys.OrderBy(n => n).Select(s => s.ToString()).ToArray();
var winners = players.
Where(Lotto => Lotto.Players.Numbers.Intersect(lotto).Count() >= 3);
//write some logic to find out who has 3 match numbers
//and assign there ticket to the winners table tblWinners
}
然而,我得到了一个错误:
"底部玩家"不包含"Where"的定义
我的所有文件中都已包含:using System.Linq;
!
看起来您正试图对players
类使用Where
扩展方法。Where
针对实现IEnumerable
的集合进行操作。
Lotto.players
是一个类,它正确地通知您在Lotto.players
类上没有名为Where
的扩展方法。IEnumerable<int> Numbers
属性将允许使用Where
。