vb.net - LINQ 选择新建

Question

我的数据表包含重复的行。我需要采取这一行。我尝试做什么

 Dim dups1 = From row In objDataSet.Tables(0).AsEnumerable() _
                       Let UserId = row.Field(Of Integer)("UserId") _
                       Group row By UserId Into grp = Group _
                       Where (grp.Count() = 2) _
                       Select grp

但我如何才能从中选择“新建”。我需要

Select New UserName = row("UserName"), UserId = row("UserId")

我如何在第一个查询中做到这一点

Answer 1

您可以选择匿名类型

Select New With { .UserName = row.Field(Of String)("Username"), .UserId = row.Field(Of Integer)("UserId") }

集成在查询中，假设UserId和UserName的组合是唯一的:

Dim dups1 = From row In objDataSet.Tables(0).AsEnumerable()
            Group row By UserCols = New With {
                Key .UserId = row.Field(Of Integer)("UserId"),
                Key .UserName = row.Field(Of String)("Username")
            } Into Group
            Where Group.Count() > 1
            Select UserCols