表名：user
欄位：Id(主鍵)
Code(編號)
RecId(外鍵,關聯Id)
select Code,(select COUNT(*) from user where RecId = u.Id) as RecCount from user as u;
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//用戶類
public class User
{
public int id { get; set; }
public string Code { get; set; }
public int RecId { get; set; }
}
//模擬資料
List<User> listUser = new List<User>();
listUser.Add(new User() { id = 1, Code = "code_1", RecId = 0 });
listUser.Add(new User() { id = 2, Code = "code_2", RecId = 1 });
listUser.Add(new User() { id = 3, Code = "code_3", RecId = 1 });
listUser.Add(new User() { id = 4, Code = "code_4", RecId = 2 });
listUser.Add(new User() { id = 5, Code = "code_5", RecId = 4 });
//運算式
var result = listUser.Select
(
u => new
{
u.Code,
RecCount = listUser.Where(tempUser => tempUser.RecId == u.id).Count()
}
);
轉載請註明出處，本文鏈接：https://www.uj5u.com/net/12984.html
標籤：ASP.NET