ASP.NET与数据库相关技巧
ASP.NET与数据库相关技巧 一、取得数据表 i 行 j 列的值
//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();
二、将数据读入DropDownList
(1) DropDownList中添加数据
//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();
(2)选中DropDownList的某项
this.DropDownList1.Items.FindByValue(dr['ClassID'].ToString().Trim()).Selected=true;//dr为DataRow
三、分类编码检索出相应的分类名称并在DataGrid中显示
(1).ASPX中的代码(ClassID为分类编码):
<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>
(2)C#代码:
/// <summary>
/// '分类'列根据数字返回文字
/// </summary>
/// <param name='IsPassed'></param>
/// <returns></returns>
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
}
作者Blog:http://blog.csdn.net/hiyavip/