如何在C＃中將此SQL轉換為LINQ？

Question

我在SQL查詢中有一個查詢，如下所示：

with pagedetail as
(
    select  
        c.componentrefid, l.name, c.startdate,
        ROW_NUMBER() over(PARTITION By c.componentrefid order by c.startdate desc) as rownumber 
    from 
        FM_componentTransaction as c 
    inner join 
        FM_LK_statusinfo as l on c.Statusinforefid = l.refid
    inner join 
        fm_scriptinfo as s on s.Refid = c.ScriptRefId
    where 
        s.CustomerInfoRefId = '85629125-7072-4EFE-9201-97E088E126C6'
)
select 
    pd.* 
from 
    pagedetail pd 
where 
    pd.rownumber = 1 

我可以得到這個輸出。 現在我的問題是如何使用實體框架實現此查詢？

Answer 1

我知道這不是您問題的直接答案，但是一種方法是在SQL中創建一個存儲過程，然后在Entity Framework中調用該存儲過程。

代碼優先： 如何在Entity Framework 6中調用存儲過程（代碼優先）？

數據庫優先： https : //msdn.microsoft.com/zh-cn/data/gg699321.aspx

Answer 2

假設您具有以下模型：

public class ComponentTransaction
{
    public Guid componentrefid { get; set; }
    public string name { get; set; }
    public DateTime startdate { get; set; }
    public Guid Statusinforefid { get; set; }
    public Guid ScriptRefId { get; set; }
}

public class Statusinfo
{
    public Guid refid { get; set; }
}

public class Scriptinfo
{
    public Guid refid { get; set; }
    public Guid CustomerInfoRefId { get; set; }
}

代碼如下所示：

Db db = new Db();
Guid customerInfoRefId = new Guid("85629125-7072-4EFE-9201-97E088E126C6");
var res = db.ComponentTransactions
    .GroupBy(c => c.componentrefid)
    .Select(g => g.OrderByDescending(c => c.startdate).First())
    .Join(db.Statusinfos, c => c.Statusinforefid, l => l.refid, (c, l) => c)
    .Join(db.Scriptinfos.Where(s => s.CustomerInfoRefId == customerInfoRefId), 
        c => c.ScriptRefId, s => s.refid, (c, s) => c);