Question

当我执行下面的代码时，收到错误消息：

LINQ to Entities无法识别方法'System.Object CompareObjectEqual（System.Object，System.Object，Boolean）'方法，并且此方法无法转换为商店表达式。

似乎发生在PCstudent的每行2的行上。

    Protected Sub btnPushSemester_Click(sender As Object, e As EventArgs) Handles btnPushSemester.Click
    Dim dbPC As New Campus6Entities
    Dim dbContext As New pbu_housingEntities
    Dim getOccupants
    Dim thisYear As String
    Dim thisTerm As String
    Using dbContext
        Dim get_Year = From p In dbContext.Configs _
                           Where p.Description = "year" _
                           Select p

        Dim get_Term = From p In dbContext.Configs _
                       Where p.Description = "term" _
                       Select p

        thisYear = get_Year.First.textValue
        thisTerm = get_Term.First.textValue
        getOccupants = From p In dbContext.Residents _
                 Where p.semester = thisTerm _
                 Where p.year = thisYear _
                 Select p

        Using dbPC
            For Each row In getOccupants
                Dim student_info = row
                Dim people_id = student_info.people_code_id
                Dim building_code = student_info.Building1.building_code
                Dim room = student_info.Room1.room1
                Dim PCstudent = From r In dbPC.RESIDENCies _
                                Where r.PEOPLE_ID = people_id _
                                Where r.ACADEMIC_YEAR = thisYear _
                                Where r.ACADEMIC_TERM = thisTerm _
                                Select r

                For Each row2 In PCstudent
                    Dim student_info2 = row2
                    student_info2.DORM_BUILDING = building_code
                    student_info2.DORM_ROOM = room
                    student_info2.RESIDENT_COMMUTER = "R"
                    student_info2.DORM_CAMPUS = "O000000001"
                    dbPC.SaveChanges()
                Next
            Next
        End Using
    End Using

End Sub

Answer 1

首先，您正在以最困难的方式（在代码中逐行更新）而不是对数据库进行单一更新;也就是说，事情表面上任何看起来都不正确。您可以检查'dbPC.Residencies'的定义以确保它被正确定义，并且您可能需要在“For Each”之前设置“if（PCStudent.Any（））”，但它应该按照书面形式工作

LINQ to Entities不支持该方法... System.Object CompareObjectEqual

1 个答案: