ASP.net怎么操作数据库

添加命名空间：using System.Data.SqlClient;
//增删查改
//string sql = "";
//SqlConnection cn=new SqlConnection("连接字符串");
//sql = "insert into table (字段1，字段2) values ('xx','aa')";//增
//sql = "delete from table where table_id ='" + ID + "'";//删
//sql = "select 字段1,字段2 from table where 条件";//查
//sql = "update table set 字段1='',字段2='' where table_id='" + ID + "' ";//改
//SqlDataAdapter da = new SqlDataAdapter(sql, cn);
//DataSet ds = new DataSet();
//da.Fill(ds);// 这样就执行了