我有2个包含通用列表属性的对象.IE浏览器：public class User
{public string Sid { get; set; }public List<Group> Groups { get; set; }
}public class Section
{public string Sid { get; set; }public List<Group> Groups { get; set; }
}从我的BLL中,我可以获得部分的通用列表列出mySections = SectionDB.getList();
我的User对象包含用户信息用户myUser = UserDB.getInfo(sid);
使用linq到对象,是否可以进行查询以检索组用户...
有没有办法强制Entity Framwork使用子查询的别名而不是为OrderBy加倍？var results = Users.Select( u => new { u.idUser, u.Name, nbChilds = u.Children.Count }).OrderBy( u => u.nbChilds );这将在SQL中转换为：SELECT [u].[idUser] AS [idUser], [u].[name] AS [Name], (SELECT COUNT(*)FROM [Children] AS [c0]
) AS [nbChilds]
FROM [Users] AS [u]
ORDER BY (SELECT COUNT(*)FROM [Children] AS [c]
)这意味着它将运行两次...
我正在使用这个库：jsinq.
我想使用子查询创建一个新对象.例如,在.NET LINQ中,我可以这样做：from a in Attendances
where a.SomeProperty = SomeValue
select new {.Property1 = a.Property1,.Property2 = a.Property2,.Property3 = (from p in Peoplewhere p.SomeProperty = a.Property3select p)
}这样我得到一个所有人的列表,其中Property3值与列表中返回的EACH对象中的出勤的Property3值相匹配.
我没有在文档或playground上看...
在LINQ中编写以下查询需要帮助.理想情况下,我想使用变量(作为参数传入)作为Top X值.建议表示赞赏.SELECT *
FROM [Link] a
WHERE ID IN (SELECT TOP 3 ID FROM [Link] bWHERE b.SiteID = a.SiteIDORDER BY a.ID)内部查询使用SiteID连接,因为我正在尝试检索每个SiteID的前3行.解决方法:那个怎么样：from l in links
where(from l2 in linkswhere l2.SiteID == l.SiteIDorderby l2.IDselect l2.ID).Take(3).Contains(l.ID)
select l这...
linq的新手试图解决这个问题.我有以下表格：Customer: Cust_Id, Name
Orders: Order_Id
CustomerOrders: Cust_Id, Order_Id我有一个这样的课：public class Customers
{
public List<Row> Rows { get; set; }public Customers(){Rows = new List<Row>();}public class Row{public int Key { get; set; }public string Name { get; set; }public List<string> Order_Ids { get; set; }}
}Linq查询是这样的：var query = from c in c...
我有两个访问表：用户和分数.Users表有列：id(自动增量用户ID),用户名,密码 – id是主键分数表包含列：id(来自用户的用户ID),highScore – 没有主键
在C#方法中,我将用户名和分数作为参数,我想插入分数表,以便在id字段中是用户的id,其用户名与提供的用户名匹配.
到目前为止,我尝试过的命令是：string insertCommand = @"INSERT INTO scores([id], [highScore])VALUES((SELECT id FROM users WHERE username = @username), @score...
有类似的东西：SELECT (SELECT COUNT(*) from Table1),(SELECT COUNT(*) from Table2 )如何在linq中编写它？还是简单不可能？
限制：
>只能打一次数据库：var result = new {Sum1 = db.Table1.Count(),Sum2 = db.Table2.Count()}); // is not valid.....>我不想使用类似的东西(使用“帮助”表)：var result = (from t3 in db.Table3select new {Sum1 = db.Table1.Count(),Sum2 = db.Table2.Count()}).firstOrDefault();//In order...
