Question

有没有办法实现＆＃39; LIKE＆＃39;在使用LINQ / .NET的日期？我尝试使用自动完成框，允许用户查找时间。

        Function GetTimesAvailable(term As String) As ActionResult
        Using db As New Context
            Dim vals = db.CalendarSlots.Where(Function(c) c.TimeStart.ToString.Contains(term)).Select(Function(c) c.TimeStart).ToList
            Return Json(vals, JsonRequestBehavior.AllowGet)
        End Using

    End Function

此代码不起作用： LINQ to Entities无法识别方法＆＃39; System.String ToString（）＆＃39;方法，并且此方法无法转换为商店表达式。

Answer 1

<Extension>
Private Function ContainsSplit(source As String, toCheck As String, comp As StringComparison)
    Dim sp = toCheck.Split(" ")

    For Each s In sp
        If source.IndexOf(s, comp) < 0 Then
            Return False
        End If
    Next

    Return True
End Function

<Extension>
Public Function GetTimesAvailable(ByVal Context As Context, term As String) As IEnumerable(Of String)
    Using db As New Context
        Dim query1 = From c In db.CalendarSlots
                     Group c By c.TimeStart Into TimeStartGroup = Count()
                    Select TimeStart

        Dim times = query1.ToList

        Dim timesAsString = From t In times
                            Select TimeStart = t.ToLongDateString & " " & t.ToLongTimeString

        Dim times2 = timesAsString.ToList

        Dim query2 = From t In times2
                Where t.ContainsSplit(term, StringComparison.OrdinalIgnoreCase)
                Select t
        Return query2.ToList
    End Using
End Function

我希望在服务器端有一种方式包含。我能想到的唯一方法是使用.toList实现查询，然后执行contains。

实体框架/ LINQ / .NET - 在日期执行'LIKE'

1 个答案: