vb.net - LINQ 集合中的 Where 语句

Question

我有一个包含 ContactNumbers 集合的 Customer 对象。
LINQ 是否可以获取其中一个联系号码 = '123' 的客户列表？

Public Class Customer
    Public Overridable Property ContactNumbers As List(Of ContactNumber)

End Class

Public Class ContactNumber

    <Required()>
    Public Property ID As Integer

    <Required()>
    <StringLength(20)>
    Public Property Number As String

    Public Overridable Property Type As ContactNumberType

    Public Property Primary As Boolean

End Class


Dim findnumber as String = '123'
Dim customers = db.customers.tolist

customers = customers.Where..... ?

Answer 1

尝试以下

customers = customers.Where(Function (x) x.ContactNumbers.Any(Function (y) y.Number = "123"))

这里的诀窍是 Any功能。这将返回 True如果集合中的任何项目与谓词匹配。在这种情况下 y.Number = 123