各种各样的连接数据库....（持续更新）

第一次接触到的数据库访问方法

string connectionstring="";
string sqlstring="";
SqlConnection sqlConnection=new SqlConnection(connectionstring);
SqlCommand cmd=new SqlCommand(sqlstring,sqlConnection);
sqlConnection.Open();
SqlDataReader reader=new cmd.ExcuteReader();
reader.Read();

第一次接触到的不连接的数据库访问

string connectionstring="";
string sqlstring="";
SqlConnection sqlConnection=new SqlConnection(connectionstring);
SqlCommand cmd=new SqlCommand (sqlstring,sqlConnection);
DataSet ds=new DataSet ();
SqlDataAdapter adapter=new SqlDataAdapter (cmd);
sqlConnection.Open();
adapter.Fill(ds,"表名");
sqlConnection.Close();
ds.Tables[0].Rows[0]["ID"]

后来接触到的更加神奇的数据库访问方法

public SqlConnection GetConnection()
    {
        string myStr = ConfigurationManager.AppSettings["ConnectionString"].ToString();
        SqlConnection myConn = new SqlConnection(myStr);
        return myConn;
    }




public System.Data.DataSet GetDataSet(string sqlStr, string TableName)
    {
        SqlConnection myConn =GetConnection();
        myConn.Open();
        SqlDataAdapter adapt = new SqlDataAdapter(sqlStr, myConn);
        DataSet ds = new DataSet();
        adapt.Fill(ds, TableName);
        myConn.Close();
        return ds;
    }