新手求解答怎么防止两个人同一时间同时注册一个账号
protected void Button1_Click(object sender, EventArgs e)
{
string strconn = "server=pc1234;database=WangDian;uid=sa;pwd=123456";//连接数据库
SqlConnection conn = new SqlConnection(strconn);
conn.Open();
SqlCommand cmd = conn.CreateCommand();
cmd.CommandText = "SELECT COUNT(*) FROM 管理员 WHERE 账号=@username and 密码=@passwd";
cmd.Parameters.Add(new SqlParameter("username", txtUserName.Text));
cmd.Parameters.Add(new SqlParameter("passwd", txtPwd.Text));
int i = Convert.ToInt32(cmd.ExecuteScalar());
if (i > 0)
{
Response.Write("<script> alert('添加数据失败!')</script>");
txtUserName.Text = "";
txtPwd.Text = "";
}
else
{
cmd.CommandText = "INSERT INTO 管理员(账号,密码)VALUES(@username,@passwd)";
int var = cmd.ExecuteNonQuery();
if (var > 0)
{
Response.Write("<script> alert('添加数据成功!')</script>");
txtUserName.Text = "";
txtPwd.Text = "";
}
conn.Close();
}
}
}
这是注册的那个按钮,怎么解决防止两个人 同一时间同时注册一个账号