我有一个数据库,其中每“n”秒插入一次 CPU 使用率,我的任务是从数据库中获取最新的 CPU 条目。我想显示属于特定服务器的数据库中的最新 CPU 条目,我想将结果保存到通用列表中。
我试过的,
string match = "ServerX"
List<UsageCPU> cpus = (from a in db.UsageCPUs
where a.ServerID.Contains(match)
group a by a.ServerID into b
orderby b.Key
select new { ServerID = b.Key,
Usage = b.FirstOrDefault() }).ToList();
我想遍历结果 cpus
以执行进一步的其他步骤。
但我得到以下错误
Cannot implicitly convert type 'System.Collections.Generic.List<AnonymousType#1>' to 'System.Collections.Generic.List<FNC_RAQIT_HM_UI.UsageCPU>'.
编辑
更新
来自 Satpal 的以下查询对我有用..但使用 var
var cpus = (from a in db.UsageCPUs
where a.ServerID.Contains(match)
group a by a.ServerID into b
orderby b.Key
select new
{
ServerID = b.Key,
Usage = b.FirstOrDefault().Usage
}).ToList();
foreach (var item in cpus)
{
if(bla bla..)
}
请帮忙!!
最佳答案
使用
List<UsageCPU> cpus = (from a in db.UsageCPUs
where a.ServerID.Contains(match)
group a by a.ServerID into b
orderby b.Key
select new UsageCPU //Added UsageCPU
{
ServerID = b.Key,
Usage = b.FirstOrDefault().Usage
}).ToList();
根据错误更新
The entity cannot be constructed in a LINQ to Entities query
List<UsageCPU> cpus = (from a in db.UsageCPUs
where a.ServerID.Contains(match)
group a by a.ServerID into b
orderby b.Key
select new
{
ServerID = b.Key,
Usage = b.FirstOrDefault().Usage
})
.AsEnumerable()
.Select(x => new UsageCPU
{
ServerID ,
Usage
}).ToList();
关于c# - 如何将通用列表<匿名类型>转换为通用列表<类名>?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/17275871/