Question

我们如何在linq子选择查询中添加where条件。

即

List<CallLog> callLog = CallLog.SampleData();
List<Contacts> contacts = Contacts.SampleData();


var q = from call in callLog
        where call.Incoming == true
        group call by call.Number into g
        select new contacts { 
                              contact.FirstName = g.FirstName, 
                              contact.LastName = g.LastName, 
                             Count = g.Count(), 
                             Avg = g.Average( c => c.Duration ) <--- WHERE c.Duration > 5, 
                             Total = g.Sum( c => c.Duration )   <--- WHERE c.Duration >= 60
                            };

如何在LINQ语句中添加“Where condition”，如上所示？

Answer 1

只需使用您描述的子句添加Where方法即可！

Avg   = g.Where(c => c.Duration > 5).Average(c => c.Duration), 
Total = g.Where(c => c.Duration >= 60).Sum(c => c.Duration)

Answer 2

你几乎拥有它：

var q = from call in callLog
        where call.Incoming == true
        group call by call.Number into g
        select new contacts { 
                contact.FirstName = g.FirstName, 
                contact.LastName = g.LastName, 
                            Count = g.Count(), 
                            Avg   = g.Where(c => c.Duration > 5).Average( c => c.Duration ),
                            Total = g.Where(c => c.Duration >= 60).Sum( c => c.Duration )
            };

linq where subselect的条件

2 个答案: