如何在EF

Question

使用count只在專欄中，我想使用的查詢在EF：

select count(number) as CountOfNumber ,number, name from table_1 group by number, name order by CountOfNumber desc 

如何使用在列數和添加此列新名稱。

Answer 1

您需要使用GroupBy，OrderBy和Count組合：

var results = (from item in db.table_1 
       group item by new { item.name, item.number } into grouping 
       orderby grouping.Count() descending 
       select new 
       { 
        name = grouping.Key.name, 
        number = grouping.Key.number, 
        CountOfNumber = grouping.Count() 
       }).ToList(); 

Answer 2

https://msdn.microsoft.com/en-us/library/bb545971.aspx

您可以使用該組的Count方法。其中context是您的實體框架數據上下文或任何IEnumerable。

var results = from t in context.table_1 
       group t by new { t.number, t.name } into g 
       orderby g.Count() descending 
       select new { number = g.Key.number, name = g.Key.name, count = g.Count() };