老师麻烦看看这个代码，有重复的还是会新增加呢？

Dim cmd As New SQLCommand
Dim dt As  DataTable
cmd.C
cmd.CommandText = "SELECT * F rom {常用账户表}"
dt = cmd.ExecuteReader(True)

Dim s As String = e.Form.Controls("TextBox9").text
s = s.Replace(" ", "")

Dim dv  As  DataRow \'否则在常用账户表查找同名的产品行,将找到的行赋值给变量dv
dv = dt.Find("[账号] = \'s \'")
If dv Is Nothing Then  \'如果找到了同名的产品行,也就是dv不是Nothing
    MessageBox.Show("该账户信息已经存在,请勿重复添加!","提示",MessageBoxButtons.OK,MessageBoxIcon.Information)
    e.Cancel=True
    Return
Else
    Dim dr As DataRow = dt.AddNew()
    dr("户名") = e.Form.Controls("TextBox10").text
    dr("账号") = s
    dr("开户银行") = e.Form.Controls("TextBox11").text
    dr.Save()
    MessageBox.Show("添加成功!","提示",MessageBoxButtons.OK,MessageBoxIcon.Information)
End If

dv = dt.Find("[账号] = \'s \'")

改成

dv = dt.Find("[账号] = \'" & s & "\'")