c# - 如何按左（列）和左（列）编写linq组

Question

我在 SQL 中有这个查询

SELECT   DISTINCT '20' + Left(charWeekNo ,2) AS title, COUNT('') AS colspan
FROM Table1 PWeek  
GROUP BY Left(charWeekNo ,2)

如何使用上述查询在 linq 中编写？

Answer 1

var PWeek = Table1
    .GroupBy(x=>x.charWeekNo.Substring(0,2))
    .Select(x=>new{title = "20" + x.Key, colspan = x.Count()})

Answer 2

var result  =Table1.GroupBy(x=>x.charWeekNo.Substring(0,2))
               .Select(g=>new {title = "20" +g.Key, colspan =g.Count()}).ToList()