sql - 如何将带有计数的sql转换为linq

Question

我如何将其转换为 linq？

select i.CatName,COUNT(*) as n_items
from ixcxs i
group by i.CatName

或者 lambda 表达式会有帮助

Answer 1

您不需要从组中选择第一个项目来获取 CatName - 请改用分组键:

var query = from i in ixcxs
            group i by i.CatName into g
            select new {
               CatName = g.Key,
               n_items = g.Count()
            };

与方法语法相同:

var query = ixcxs.GroupBy(i => i.CatName)
                 .Select(g => new { CatName = g.Key, n_items = g.Count() });