ผมอยากทราบว่า โค้ดเขียน autoID ที่เป็น ตัวอักษรผมสมกับตัวเลข เช่น B0001จะเขียนยังไงครับ ในโปรแกรม C#

      Select  Top(1)  CONVERT(varchar,(CompCode+1)) From Cust_Company  Order by CompCode desc

public void maxKey()
{
	string s = null;
	int n = 0;
	Sql = "SELECT MAX(RIGHT(p_id,4)) AS maxKey " + "FROM tbBudgets " + "WHERE p_year='" + ddlp_year.Text + "'";
	db.connectdb();
	cm = new SqlCommand(Sql, db.cn);
	rs = cm.ExecuteReader;
	rs.Read();
	if (object.ReferenceEquals(rs("maxKey"), DBNull.Value)) {
		s = "0001";
	} else {
		n = rs("maxKey");
		n += 1;
		s = n.ToString("0000");
	}
	db.closedb();

	lblp_id.Text = "pb" + ddlp_year.Text.Substring(2, 2) + s;

	Sql = null;

}

public void maxKey()
{
	string s = null;
	int n = 0;
	Sql = "SELECT MAX(RIGHT(p_id,4)) AS maxKey " + "FROM tbBudgets " + "WHERE p_year='" + ddlp_year.Text + "'";
	db.connectdb();
	cm = new SqlCommand(Sql, db.cn);
	rs = cm.ExecuteReader;
	rs.Read();
	if (object.ReferenceEquals(rs("maxKey"), DBNull.Value)) {
		s = "0001";
	} else {
		n = rs("maxKey");
		n += 1;
		s = n.ToString("0000");
	}
	db.closedb();

	lblp_id.Text = "pb" + ddlp_year.Text.Substring(2, 2) + s;

	Sql = null;

}