变量名＆＃39; @ userid2＆＃39;已经宣布。变量名在查询批处理或存储过程中必须是唯一的

Question

这是我第一次在这里提问。我正在开发一个项目，我必须更新一个表，并使用事务插入到另一个表中。

事务块的插入部分将来自所选gridview行的内容。

我得到的错误是：

  

变量名称＆＃39; @ userid2＆＃39;已经宣布。变量名在查询批处理或存储过程中必须是唯一的。

如何解决此错误？

这是我的代码：

  Protected Sub btnmodifyaccessdepot_Click(sender As Object, e As EventArgs) Handles btnmodifyaccessdepot.Click
        Using con As New SqlConnection(ConString)
            con.Open()
            Dim sqlTran As SqlTransaction = con.BeginTransaction()
            Dim command As SqlCommand = con.CreateCommand()
            command.Transaction = sqlTran

        Try

            command.CommandText = "UPDATE Rhema_TechnicalAccess set Active=@Active,Requester= @Requester,Approver=@Approver,Issuer=@Issuer where userid=@userid"
            command.Parameters.AddWithValue("@Active", lblactiveadd.Text)
            command.Parameters.AddWithValue("@Requester", lblrequesterAdd.Text)
            command.Parameters.AddWithValue("@Approver", lblapproveradd.Text)
            command.Parameters.AddWithValue("@Issuer", lblisssueradd.Text)
            command.Parameters.AddWithValue("@Userid", lblselecteduserid.Text)
            command.ExecuteNonQuery()



            For Each row As GridViewRow In gridadddepot.Rows
                If row.RowType = DataControlRowType.DataRow Then
                    Dim chkdepots As CheckBox = DirectCast(row.FindControl("chkdepots"), CheckBox)
                    If chkdepots.Checked Then
                        Dim lbldepot As TextBox = DirectCast(row.FindControl("lbldepot"), TextBox)



                        command.CommandText = "INSERT INTO Rhema_TechnicalAccessDepot VALUES(@userid2,@Depot,@Access,@TechnicalAccessID)"
                        command.Parameters.AddWithValue("@userid2", lblselecteduserid.Text)
                        command.Parameters.AddWithValue("@Depot", lbldepot.text)
                        command.Parameters.AddWithValue("@Access", lbluseraccessAdd.Text)
                        command.Parameters.AddWithValue("@technicalaccessid", lbltechnicalaccessid.Text)
                    End If
                End If
            Next

            command.ExecuteNonQuery()

            sqlTran.Commit()


            lblmessage2.Text = "Both records were written to database."
        Catch ex As Exception
            lblmessage2.Text = ex.Message

            Try
                sqlTran.Rollback()
            Catch exRollback As Exception
                lblmessage2.Text = exRollback.Message
            End Try
        End Try
    End Using
         End Sub