ASP.NET与数据库相关技巧

//建立并打开数据库连接 

OleDbConnection conn=new OleDbConnection(); 

conn.ConnectionString=strConnectionString;//strConnectionString为数据库连接字符串 

conn.Open(); 



string sql="select * from NewsClass order by ClassId desc"; 

string x; 

DataSet ds=new DataSet(); 

OleDbDataAdapter da=new OleDbDataAdapter(sql,conn); 

da.Fill(ds,"NewsTable"); 

DataTable dt=ds.Tables["NewsTable"]; 

x=dt.Rows[i][1].ToString()//数据表i行j列的值 

conn.close(); 

//建立并打开数据库连接 

OleDbConnection conn=new OleDbConnection(); 

conn.ConnectionString=strConnectionString;//strConnectionString为数据库连接字符串 

conn.Open(); 



string sql="select * from NewsClass order by ClassId desc"; 

//建立数据集 

DataSet ds=new DataSet(); 

OleDbDataAdapter da=new OleDbDataAdapter(sql,conn); 

da.Fill(ds,"NewsTable"); 

this.DropDownList1.DataSource=ds; 

this.DropDownList1.DataTextField = "ClassName";//Text值 

this.DropDownList1.DataValueField = "ClassID";//Value值 

this.DropDownList1.DataBind(); 



conn.Close(); 

this.DropDownList1.Items.FindByValue(dr["ClassID"].ToString().Trim()).Selected=true;
//dr为DataRow 

<asp:TemplateColumn HeaderText="类 别"> 

<ItemTemplate> 

<asp:Label id=lblClass runat="server" 
Text='<%# GetClassName(Convert.ToInt32(DataBinder.Eval(Container, 
"DataItem.ClassID"))) %>'> 

</asp:Label> 

</ItemTemplate> 

</asp:TemplateColumn> 

/// 
 

/// "分类"列根据数字返回文字 

/// 
 

///  

///  

public string GetClassName(int ClassID) 

{ 

OleDbConnection conn=new OleDbConnection(); 

conn.ConnectionString=strConnectionString; 

conn.Open(); 



string sql="select * from NewsClass where ClassID="+ClassID; 

DataSet ds=new DataSet(); 

OleDbDataAdapter da=new OleDbDataAdapter(sql,conn); 

da.Fill(ds,"ClassTable"); 

DataTable dt=ds.Tables["ClassTable"]; 

string strClassName=dt.Rows[0]["ClassName"].ToString(); 

conn.Close(); 



return strClassName;//返回 ClassID对应的ClassName 

}