static void Main(string[] args) { SqlFuns sf = new SqlFuns(); IList <Student> st = sf.SearchStudent(true); for (int i = 2; i < st.Count; i++) { StudentRank t = new StudentRank(); t.Stnum = st[i].Stnum; t.Rank = 1; t.Date = st[i].Joindate; sf.AddStudentRank(t); } }