求数据库查询代码,该如何解决_ASP.NET

求数据库查询代码
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查询
C#的，应该连接数据库再写查询语句吧，就是不会写连接数据库的代码，没头绪，大家帮忙，好吧
namespace MASTER_ANCN
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

private void btnsearch_Click(object sender, EventArgs e)
{
using System. date.SQLClient;
SQLConnection SQLConn = new Connection();
string sql=Select *From ;
SQLConn. ConnectionString="myconnectionstring";
SQLConn. open();

}
}
}
应该缺了很多东西，不知道该怎么写了，不会

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C# code

   public DataTable GetDataTable(string sql)        {                      SQLConnection conn = new OleDbConnection(@"连接字符串");            SQLDbDataAdapter SQLda = new OleDbDataAdapter(sql, conn);            DataTable dt = new DataTable();            SQLda.Fill(dt);            return dt;                }
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探讨
给我也不知道怎么改啊
怎么加啊
哎，基础太差啊

------解决方案--------------------------------------------------------
private static DataSet SelectRows(DataSet dataset,
   string connectionString,string queryString)  
{
   using (SqlConnection connection =  
       new SqlConnection(connectionString))
   {
       SqlDataAdapter adapter = new SqlDataAdapter();
       adapter.SelectCommand = new SqlCommand(
           queryString, connection);
       adapter.Fill(dataset);
       return dataset;
   }
}
楼主买本书，好好看看吧
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C# code        string ConStr = "Persist Security Info=False;Initial Catalog=FilmManger;";        ConStr += "Data Source=.;Integrated Security=SSPI;";//连接串不懂自己去看。        SqlConnection myCon = new SqlConnection(ConStr);        string ComStr = "select EmployeeID,Name,Sex,Age,Address,Tile from  employee";        SqlCommand myCom = new SqlCommand(ComStr, myCon);        SqlDataAdapter myDA = new SqlDataAdapter();        myDA.SelectCommand = myCom;        myCon.Open();        DataSet myDS = new DataSet();        myDA.Fill(myDS, "employee");        DataView myDV = myDS.Tables["employee"].DefaultView;        myDV.Sort = "age";        this.GridView1.DataSource = myDV;        this.GridView1.DataBind();        myCon.Close();
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去下载dbhelper数据操作类！都写好的
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C# codeprivate static SqlConnection GetConnection()        {            string myStr = ConfigurationManager.ConnectionStrings["ConnectionString"].ToString();            SqlConnection myConn = new SqlConnection(myStr);            return myConn;        }try            {                SqlConnection myConn = GetConnection();                myConn.Open();                SqlCommand myComm_1 = new SqlCommand(sqlstr_1, myConn);                SqlCommand myComm_2 = new SqlCommand(sqlstr_2, myConn);                myComm_1.ExecuteNonQuery();                myComm_2.ExecuteNonQuery();                myConn.Close();                flag = true;            }            catch (Exception ex)            {                logger.Error(ex);                throw;            }