问一个ASP.NET的问题，看不懂循环的代码……

我看过这样一段代码：

//大类带文章部分循环开始
OleDbConnection constring = DB.Getconn();

DataSet ds = new DataSet();
string sql2 = "select top 8 * from Category order by cate_Order";
OleDbDataAdapter sda1 = new OleDbDataAdapter(sql2, constring);
sda1.Fill(ds, "big");

string sql3 = "select a.* from Content a where a.log_ID in (select top 10 log_ID from Content where log_CateID = a.log_CateID order by log_ID desc) order by log_ID desc";
OleDbDataAdapter sda2 = new OleDbDataAdapter(sql3, constring);
sda2.Fill(ds, "small");

ds.Relations.Add("myrelation", ds.Tables["big"].Columns["cate_ID"], ds.Tables["small"].Columns["log_CateID"]);
dlCategories.DataSource = ds.Tables["big"].DefaultView;
dlCategories.DataBind();
//大类带文章循环部分结束