Question

c#中SqlCommandBuilder更新数据库的问题

下面的程序有哪里错了吗？我的userlogin表里设了username是主键，我运行的时候它不显示任何错误，但是数据库里面的数据没有更新，为什么呢？要怎么改啊？？谢谢了
SqlConnection conn = new SqlConnection("server=(local);uid=sa;pwd=123456;database=auction");
string str = "select * from userlogin where username='"+Session["username"]+"'";

SqlDataAdapter adapter = new SqlDataAdapter(str,conn);
SqlCommandBuilder cb = new SqlCommandBuilder(adapter);

DataTable table = new DataTable();

adapter.Fill(table);

DataRow newrow =table.Rows[0];
newrow["username"] = TextBox1.Text.Trim();
newrow["userpwd"] = TextBox2.Text.Trim();
newrow["sex"] = RadioButtonList1.SelectedItem.Text.Trim();
newrow["address"] = TextBox3.Text.Trim();

adapter.Update(table);

Answer 1

DataTable table = new DataTable();

adapter.Fill(table);

DataRow newrow =table.Rows[0];
newrow["username"] = TextBox1.Text.Trim();
newrow["userpwd"] = TextBox2.Text.Trim();
newrow["sex"] = RadioButtonList1.SelectedItem.Text.Trim();
newrow["address"] = TextBox3.Text.Trim();
改
DataSet myds= new DataSet ();

adapter.Fill(myds);

DataRow newrow =myds.Tables[0].NewRow();
newrow["username"] = TextBox1.Text.Trim();
newrow["userpwd"] = TextBox2.Text.Trim();
newrow["sex"] = RadioButtonList1.SelectedItem.Text.Trim();
newrow["address"] = TextBox3.Text.Trim();
myds.Tables[0].Rows.Add(newrow);
adapter.Update(myds);