我想問一下自動增量ID。像us001到us002註冊文本框。如何自動增量ID
這是我的代碼到目前爲止。
namespace login
{
public partial class SignUp : Form
{
public SignUp()
{
InitializeComponent();
}
private void SignUp_Load(object sender, EventArgs e){
autogenerateid();
}
SqlConnection con = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Users\Azis\documents\visual studio 2010\Projects\1801405462(OOD)\1801405462(OOD)\cake.mdf;Integrated Security=True;User Instance=True");
string userid = "UserID";
private void autogenerateid() {
SqlConnection con = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Users\Azis\documents\visual studio 2010\Projects\1801405462(OOD)\1801405462(OOD)\cake.mdf;Integrated Security=True;User Instance=True");
con.Open();
SqlCommand cmd = new SqlCommand("select Count(UserID) from User", con);
int i = Convert.ToInt32(cmd.ExecuteScalar());
con.Close();
i++;
useridnumber.Text = userid + i.ToString();
}
如何'autogenerateid()'應該叫什麼名字? –
'i ++'有什麼問題? –
這是一個數據庫,爲什麼不直接將該屬性添加到列? – Eris