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C# SQL的等效C LINQ代码_C#_Sql_Linq_Join_Group By - Fatal编程技术网

C# SQL的等效C LINQ代码

C# SQL的等效C LINQ代码,c#,sql,linq,join,group-by,C#,Sql,Linq,Join,Group By,c、 我是LINQ新手,有下面的SQL代码,我想要一个等价的c LINQ SELECT COUNT(c.sId) ,a.Activity FROM FillStat c INNER JOIN Activity a ON a.Id = c.ActivityID WHERE c.pId= 300 GROUP BY a.Activity 使用查询语法,它将如下所示: var result = from c in db.FillStat join a

c、 我是LINQ新手,有下面的SQL代码,我想要一个等价的c LINQ

SELECT
    COUNT(c.sId)
    ,a.Activity
FROM FillStat c
INNER JOIN Activity a
    ON a.Id = c.ActivityID
WHERE c.pId= 300
GROUP BY a.Activity

使用查询语法,它将如下所示:

var result = from c in db.FillStat
             join a in db.Activity on c.ActivityID equals a.Id
             where c.pId = 300
             group 1 by a.Activity into g
             select new {
                 Activity = g.Key,
                 Count = g.Count()
             };

使用查询语法,它将如下所示:

var result = from c in db.FillStat
             join a in db.Activity on c.ActivityID equals a.Id
             where c.pId = 300
             group 1 by a.Activity into g
             select new {
                 Activity = g.Key,
                 Count = g.Count()
             };

pId也属于哪个表?@juharr它属于FillStatvar results=from c in db.FillStat from a in c.Activities其中c.pId=300组c.sId by a.Activity in grp select new{Activity=grp.Key,Count=grp.Count}最大的区别是select是Linq中的最后一件事,而不是第一件事,这对我来说更有意义。我建议查找列表理解和map/reduce的一般概念,特别是如果你想将所学知识应用于其他语言。pId也属于哪个表?@juharr它属于FillStatvar results=from c in db.FillStat from a in c.Activities其中c.pId=300 group c.sId by a.Activity in grp选择new{Activity=grp.Key,Count=grp.Count}最大的区别是,select是Linq中的最后一项,而不是第一项,这对我来说更有意义。我建议查找列表理解和映射/减少的一般概念,特别是如果您想将所学应用于其他语言。