Question

标量变量问题存在问题。输出说代码需要声明fname标量变量。代码如下所示。任何帮助将不胜感激。

Dim conn As SqlConnection
Dim cmd As SqlCommand

Dim fname As String = firstname.Text
Dim strSurname As String = surname.Text
Dim strAddress As String = address.Text
Dim strGraveType As String

Dim GraveNo1 As String
Dim GraveNo2 As String
Dim GraveNo3 As String

Dim filename As String
Dim photoFilePath As String

If Not radSingle.Checked Or radDouble.Checked Or radTreble.Checked Then
    MsgBox("Please Select a Grave Type")
ElseIf radSingle.Checked Then
    strGraveType = "Single"
ElseIf radDouble.Checked Then
    strGraveType = "Double"
ElseIf radTreble.Checked Then
    strGraveType = "Treble"
End If

GraveNo1 = txtGraveNo1.Text
GraveNo2 = txtGraveNo2.Text
GraveNo3 = txtGraveNo3.Text


If GravePhotoUpload.HasFile Then
    If GravePhotoUpload.PostedFile.ContentType = "image/jpeg" Then

       Try
           filename = Path.GetFileName(GravePhotoUpload.FileName)
           GravePhotoUpload.SaveAs(Server.MapPath("../Images/") + filename)
           photoFilePath = "Images/" + filename
       Catch ex As Exception
           MsgBox("ERROR - The file could not be uploaded. The following error occured: " + ex.Message)

       End Try
    Else
       MsgBox("Please upload a JPG File Format")
    End If
End If

Dim cmdstring As String = "INSERT INTO DeathRecords(FirstName, Surname, Address, GraveType, GraveNo1, GraveNo2, GraveNo3, GravePhoto) Values (@Fname, @strSurname, @strAddress, @strGraveType, @GraveNo1, @GraveNo1, @GraveNo3, @photoFilePath)"

conn = New SqlConnection("Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\DrumcreeCemetery.mdf;Integrated Security=True")
cmd = New SqlCommand(cmdstring, conn)

cmd.Parameters.AddWithValue("@FirstName", fname)
cmd.Parameters.AddWithValue("@Surname", strSurname)
cmd.Parameters.AddWithValue("@Address", strAddress)
cmd.Parameters.AddWithValue("@GraveType", strGraveType)
cmd.Parameters.AddWithValue("@GraveNo1", GraveNo1)
cmd.Parameters.AddWithValue("@GraveNo2", GraveNo2)
cmd.Parameters.AddWithValue("@GraveNo3", GraveNo3)
cmd.Parameters.AddWithValue("@GravePhoto", photoFilePath)

Try
    conn.Open()
    cmd.ExecuteNonQuery()
    conn.Close()
Catch ex As Exception
    MsgBox(ex.Message)
End Try

Answer 1

查询中定义的参数：

Dim cmdstring As String = "INSERT INTO DeathRecords(FirstName, Surname, Address, GraveType, GraveNo1, GraveNo2, GraveNo3, GravePhoto) Values (@Fname, @strSurname, @strAddress, @strGraveType, @GraveNo1, @GraveNo1, @GraveNo3, @photoFilePath)"

与您在命令中设置的参数不匹配：

cmd.Parameters.AddWithValue("@FirstName", fname)
cmd.Parameters.AddWithValue("@Surname", strSurname)
cmd.Parameters.AddWithValue("@Address", strAddress)
cmd.Parameters.AddWithValue("@GraveType", strGraveType)
cmd.Parameters.AddWithValue("@GraveNo1", GraveNo1)
cmd.Parameters.AddWithValue("@GraveNo2", GraveNo2)
cmd.Parameters.AddWithValue("@GraveNo3", GraveNo3)
cmd.Parameters.AddWithValue("@GravePhoto", photoFilePath)

例如，您的查询对于FirstName有@Fname，但您要为FirstName参数指定@FirstName。大多数其他变量也是如此。如果Command中给定的参数名称与查询中的参数名称不匹配，则Command无法将您指定的参数链接到查询所期望的内容，从而导致您获得的错误。

标量变量的问题

1 个答案: