c# – 将SQL查询转换为LINQ

前端之家收集整理的这篇文章主要介绍了c# – 将SQL查询转换为LINQ前端之家小编觉得挺不错的,现在分享给大家,也给大家做个参考。
我有一个名为visit的表,其中包含以下列:
visit_Id
member_Id 
visit_Date 
visit_Time 
visit_DateTime 
visit_Status values like (accepted,refused)

我有以下SQL查询

string sql = @"SELECT CONCAT(UPPER(SUBSTRING(visit_Status,1,1)),SUBSTRING(visit_Status FROM 2))  as Status,COUNT('x') AS Visits
   FROM visits
   WHERE visit_Date BETWEEN '2001-09-08' AND '2009-09-09'
   GROUP BY visit_Status";

如何将此sql转换为LINQ?我的实体名称是dbcontext.在此先感谢您的帮助.

解决方法

你需要使用 EntityFunctions
DateTime dateFrom = new DateTime(2001,9,8);
DateTime dateTo = new DateTime(2001,9);

var query = from v in dbcontext.Visits
            where v.visit_Date >= dateFrom && v.visit_Date <= dateTo
            group v by v.visit_Status into vg
            select new
            {
              Status = EntityFunctions.Concat(EntityFunctions.ToUpper(vg.Key[0]),EntityFunctions.SubString(1,EntityFunctions.Length(vg.Key) -1),Visits = vg.Count()
            }
原文链接:https://www.f2er.com/csharp/100553.html

猜你在找的C#相关文章