string sql = " select T_ID,T_RealName,T_Sex ,T_Telephone,C_Name from Teacher inner join Class on Teacher.C_ID =Class.C_ID where Teacher.T_RealName like'%" + tname + "%'";
com = new SqlCommand(sql, con);
dr = com.ExecuteReader();
con.Open(); string sql = " select T_ID,T_RealName,T_Sex ,T_Telephone,C_Name from Teacher inner join Class on Teacher.C_ID =Class.C_ID where Teacher.T_RealName like'%" + tname + "%'"; com = new SqlCommand(sql, con); dr = com.ExecuteReader(); dr.Read(