新手求指导帮助

[maojin1]

public partial class formMain : Form
{
public bool modifi = false;
public string myname;
SqlDataAdapter adapter, adapter1, adapter2;
DataSet ds, ds1, ds2;
public formMain()
{
InitializeComponent();
string str = @"Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Documents and Settings\Administrator\桌面\学生信息管理系统\WindowsApplication3\DATA\maojin.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True";
SqlConnection con = new SqlConnection(str);
string sqlstr = "select * from 学生表";
adapter = new SqlDataAdapter(sqlstr, con);
SqlCommandBuilder builder = new SqlCommandBuilder(adapter);
adapter.InsertCommand = builder.GetInsertCommand();
adapter.UpdateCommand = builder.GetUpdateCommand();
ds = new DataSet();
adapter.Fill(ds, "学生表");
this.dataGrid1.DataSource = ds.Tables["学生表"];
con.Close();
}


求怎么理解这些代码??

[nigerenz]

public partial class formMain : Form
{
public bool modifi = false;
public string myname;
SqlDataAdapter adapter, adapter1, adapter2; //定义数据库读取对象
DataSet ds, ds1, ds2; //定义数据集
public formMain()
{
InitializeComponent();

数据库连接字段
string str = @"Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Documents and Settings\Administrator\桌面\学生信息管理系统\WindowsApplication3\DATA\maojin.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True";

数据库连接对象
SqlConnection con = new SqlConnection(str);
string sqlstr = "select * from 学生表"; 查询语句
adapter = new SqlDataAdapter(sqlstr, con);执行查询语句，根据数据库连接读取数据库
SqlCommandBuilder builder = new SqlCommandBuilder(adapter);
adapter.InsertCommand = builder.GetInsertCommand();
adapter.UpdateCommand = builder.GetUpdateCommand();
ds = new DataSet();
adapter.Fill(ds, "学生表");把查询到的结果，填充到数据集中保存
this.dataGrid1.DataSource = ds.Tables["学生表"]; 数据绑定，
con.Close(); 关闭数据链接，每次数据查询完成后，都要关闭数据库链接
}

[冬雨在路上]

public partial class formMain : Form
  {
  public bool modifi = false;
  public string myname;
  SqlDataAdapter adapter, adapter1, adapter2; //定义数据库读取对象
  DataSet ds, ds1, ds2; //定义数据集
  public formMain()
  {
  InitializeComponent();

  //数据库连接字段，可以到www.connectionstrings.com查看更多的连接串
  string str = @"Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Documents and Settings\Administrator\桌面\学生信息管理系统\WindowsApplication3\DATA\maojin.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True";

  //数据库连接对象   
  SqlConnection con = new SqlConnection(str);
  string sqlstr = "select * from 学生表";//sql 查询语句
  adapter = new SqlDataAdapter(sqlstr, con);//执行查询语句，根据数据库连接读取数据库
  SqlCommandBuilder builder = new SqlCommandBuilder(adapter);
  adapter.InsertCommand = builder.GetInsertCommand();
  adapter.UpdateCommand = builder.GetUpdateCommand();
  ds = new DataSet();
  adapter.Fill(ds, "学生表");//把查询到的结果，填充到数据集中保存
  this.dataGrid1.DataSource = ds.Tables["学生表"]; //数据绑定，
  con.Close(); //关闭数据链接，每次数据查询完成后，都要关闭数据库链接
  }