vb消息顯示

-2

當我點擊註冊按鈕時，即使我沒有在列上輸入任何東西，我也會得到測試"registration successful"。
如果成功插入數據庫，我需要顯示"registration successful"。
如果它是失敗的，我需要它相同的標籤（lblsuccessfail）vb消息顯示

Imports System.Data.SqlClient 
Imports System.IO 

Partial Class register 
    Inherits System.Web.UI.Page 


    Dim cn As New SqlConnection("Data Source=localhost\MSSQL2012;Initial Catalog=UserDetails;Integrated Security=True") 
    Dim cmd As New SqlCommand 
    Dim da As New SqlDataAdapter 


    Protected Sub Button1_Click(sender As Object, e As System.EventArgs) Handles btnnew.Click 
     cn.Open() 


     Try 


      Dim Query As String 

      Query = "INSERT INTO FirstProject (fullname,username,password,address,gender)VALUES('" & txtfullname.Text & "', '" & txtusername.Text & "','" & txtpassword.Text & "','" & txtaddress.Text & "','" & cbogender.Text & "')" 

      cmd = New SqlCommand(Query, cn) 


      If cmd.ExecuteNonQuery() Then 

       lblsuccessfail.Text = lblsuccessfail.Text & " Registertration successful " 

      End If 

     Catch ex As Exception 

      lblsuccessfail.Text = lblsuccessfail.Text & " Registertration unsuccessful " 


     End Try 

     cn.Close() 
    End Sub 

    Protected Sub Page_Load(sender As Object, e As System.EventArgs) Handles Me.Load 

    End Sub 

    Protected Sub btnback_Click(sender As Object, e As System.EventArgs) Handles btnback.Click 
     Response.Redirect("login.aspx") 
    End Sub 
End Class

來源

2016-06-07 dasran rajlui

的ExecuteNonQuery返回插入的行數的話，如果你的數據庫接受一個空的記錄上顯示"registration fail"，你的代碼總是成功的。您需要在代碼或數據庫本身中爲這種可能性添加檢查。順便說一下，如果啓用了Option Strict On，您的代碼將永遠不會編譯，從而警告您ExecuteNonQuery的問題並幫您自己一個忙。瞭解如何使用參數化查詢。 – Steve

如果您沒有向文本框添加任何內容，它仍然保存爲空。在插入代碼之前，您的代碼不檢查任何值。閱讀空值，並添加條件來檢查它們。 – jitendragarg

Imports System.Data.SqlClient 
Imports System.IO 

Partial Class register 
    Inherits System.Web.UI.Page 


    Dim cn As New SqlConnection("Data Source=localhost\MSSQL2012;Initial Catalog=UserDetails;Integrated Security=True") 
    Dim cmd As New SqlCommand 
    Dim da As New SqlDataAdapter 


    Protected Sub Button1_Click(sender As Object, e As System.EventArgs) Handles btnnew.Click 
     Try 

      cn.Open() 


      cmd = New SqlCommand("INSERT INTO FirstProject (fullname,username,password,address,gender)VALUES('" & txtfullname.Text & "', '" & txtusername.Text & "','" & txtpassword.Text & "','" & txtaddress.Text & "','" & cbogender.Text & "')", cn) 

      If txtfullname.Text = Nothing OrElse txtusername.Text IsNot Nothing Or txtpassword.Text.Equals(Nothing) OrElse txtaddress.Text = String.Empty Or cbogender.Text.Equals(String.Empty) Then Throw New Exception() 

      If cmd.ExecuteNonQuery() Then lblsuccessfail.Text = lblsuccessfail.Text & " Registertration successful " 

     Catch ex As Exception 

      lblsuccessfail.Text = lblsuccessfail.Text & " Registertration unsuccessful " 

     Finally 
      cn.Close() 
     End Try 

    End Sub 

    Protected Sub Page_Load(sender As Object, e As System.EventArgs) Handles Me.Load 

    End Sub 

    Protected Sub btnback_Click(sender As Object, e As System.EventArgs) Handles btnback.Click 
     Response.Redirect("login.aspx") 
    End Sub 
End Class

來源

2016-06-10 07:18:23 Happypig375

如果列是空白的，現在它將成爲不成功的註冊。 – Happypig375

另請注意對代碼的其他更改。 – Happypig375

回答

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