Question

问候男人和女孩，

我最近才刚刚开始在ASP.NET和VB.NET中进行编程，因此我一直在研究语法和逻辑。无论如何，我有一个SQL查询，该查询根据输入的用户名获取用户的详细信息。我的问题是：由于我从数据库表中进行了SELECT *，我该如何将这些值放入变量中？我想保存到变量的值是ID，Firstname和Lastname。我的计划是保存登录的当前用户ID，这样它将在我的应用程序中全部显示。

这就是我所拥有的：

Protected Sub btnSubmit_Click(sender As Object, e As EventArgs) Handles btnSubmit.Click
    Dim strconn As New SqlConnection

    If strconn.State = ConnectionState.Closed Then
        strconn.ConnectionString = ("Server=0.0.0.0;Database=Test;Uid=test;Pwd=test;")
    End If


    '//prompt user for blank user credentials
    If txtUsername.Text.Length = 0 Then
        Response.Write("<SCRIPT LANGUAGE=""JavaScript"">  alert('You must enter your Access Credentials.');</script>")

        'If MsgBox("You must enter your Access Credentials.", vbInformation, vbOKCancel) Then
        'End If
        txtUsername.Focus()
        Exit Sub
    End If

    Try
        strconn.Open()
        Dim sQuery As String = "SELECT * from tblUsers WHERE username = '" & txtUsername.Text & "'" &
                               " AND password = '" & txtPassword.Text & "'" &
                               " AND status ='" & "1" & "'"

        Dim datareader As SqlDataReader
        Dim adapter As New SqlDataAdapter
        Dim parameter As New SqlParameter
        Dim command As SqlCommand = New SqlCommand(sQuery, strconn)
        command.Connection = strconn
        adapter.SelectCommand = command
        datareader = command.ExecuteReader()

        If datareader.HasRows Then
            datareader.Read()
            'MsgBox("Login Successfull!     ", vbInformation, vbOKOnly)
            'Response.Redirect("http://localhost:0000/SecurityStaffDataEntry.aspx")
            Response.Redirect("http://localhost:0000/index.aspx")
            datareader.Close()
            LoginOk = True

        Else
            Response.Write("<SCRIPT LANGUAGE=""JavaScript"">  alert('Invalid Username or Password!');</script>")
            ' MsgBox("Invalid Username or Password!    ", vbInformation, vbOKOnly)
            txtUsername.Text = ""
            txtPassword.Text = ""
            txtUsername.Focus()
        End If
        datareader.Close()

    Catch ex As Exception
        'MsgBox(ex.Message)
    End Try


End Sub

Answer 1

将其放在reader.Read（）之后，并用变量替换文本框

while (reader.Read())
{
    TextBox1.Text = reader[0].ToString();
}

您也可以使用

reader["columnname"].ToString()

如何将查询中的SQL值保存到变量中？

1 个答案: