Question

我知道这是基本的，但是如何实现返回最常出现的字段的linq查询？

这是我到目前为止所得到的：

var commonAge = from c in customers.GroupBy(s=>s.age)
                                   .OrderByDescending(sg=>sg.Count())
                                   .Take(1)
                select s.Key;

Answer 1

根据您的评论，您正在寻找具有所述属性的客户数据类型上最常见的Age。

// Start with the customers collection
var mostCommonAge = customers
// then group by their age, 
    .GroupBy(c => c.Age,
// and project into a new anonymous type
        (key, g) => new {Age = key, Count = g.Count()})
// order by count of each age
    .OrderByDescending(g => g.Count)
// and take the first
    .First();

这是一个完整的工作示例。使用数据模型类Customer：

class Customer {
    public string Name { get; set; }
    public int Age { get;set; }
}

然后您可以按

输出最常见的年龄

static void Main(string[] args) {
    var customers = new List<Customer> { 
        new Customer { Age = 23 }, 
        new Customer { Age = 23 }, 
        new Customer { Age = 23 }, 
        new Customer { Age = 24 }, 
        new Customer { Age = 25 } 
        };

    var mostCommonAge = customers
        .GroupBy(c => c.Age,
            (key, g) => new {Age = key, Count = g.Count()})
        .OrderByDescending(g => g.Count)
        .First();

    Console.WriteLine(mostCommonAge);

}

Linq查询类的大多数属性

1 个答案: