vb.net仅返回来自linq.IQueryable的选定列/字段

Question

对不起我的英语。

我一直在网上寻找“动态Linq查询”，我发现了一个对我有用的工具。 Guide to Creating Dynamic LINQ Queries。我在线转换器将其转换为VB。其结果是

Public Shared Function GetFilteredDataWithPage(Customer As String, Itemdesc As String, JoNumber As String) 
    Dim DB As New JoDataClassesDataContext 
    Dim DataQuery As IQueryable(Of JoMainTbl) = DB.JoMainTbls 

    If Customer.Trim().Length > 0 Then 
     DataQuery = DataQuery.Where(Function(a) a.Customer.StartsWith(Customer)) 
    End If 
    If Itemdesc.Trim().Length > 0 Then 
     DataQuery = DataQuery.Where(Function(a) a.ItemDescription.StartsWith(Itemdesc)) 
    End If 
    If JobNumber.Trim().Length > 0 Then 
     DataQuery = DataQuery.Where(Function(a) a.JoNumber = JoNumber) 
    End If 
    Return DataQuery 
    End Function 

我有5个字段

“JONumber，样品，dateCreated会，顾客，ItemDesc”

，并显示它

DataGridView.DataSource = GetFilteredData(TxtCustomer.Text, TxtItemDesk.Text, TxtJobNumber.Text) 

的问题的表是否我希望它仅以此顺序显示文件“JONumber，Customer，ItemDesc”。所有的帮助都非常感谢。先谢谢你。

Answer 1

由于@MarcinJuraszek在评论所说，你应该使用一个Select这样的：

Public Shared Function GetFilteredDataWithPage(Customer As String, Itemdesc As String, JoNumber As String) 
    Dim DB As New JoDataClassesDataContext 
    Dim DataQuery As IQueryable(Of JoMainTbl) = DB.JoMainTbls 

    If Customer.Trim().Length > 0 Then 
     DataQuery = DataQuery.Where(Function(a) a.Customer.StartsWith(Customer)) 
    End If 
    If Itemdesc.Trim().Length > 0 Then 
     DataQuery = DataQuery.Where(Function(a) a.ItemDescription.StartsWith(Itemdesc)) 
    End If 
    If JobNumber.Trim().Length > 0 Then 
     DataQuery = DataQuery.Where(Function(a) a.JoNumber = JoNumber) 
    End If 
    Return DataQuery.Select(Function(x) New With {.JONumber=x.JONumber, .Customer=x.Customer, .ItemDesc=x.ItemDesc}) 
    End Function