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ASP.NET入門(mén)數(shù)據(jù)篇

2020-01-18 01:55:51
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供稿:網(wǎng)友

對(duì)于網(wǎng)站編程的初學(xué)者來(lái)說(shuō),總是會(huì)上網(wǎng)找些源碼來(lái)看,但久而久之還是停留在改代碼的階段,并不明白怎樣去寫(xiě)一個(gè)完整的網(wǎng)站程序.有見(jiàn)如此我就開(kāi)始寫(xiě)這樣的文章(c#版),不足之處請(qǐng)批評(píng)指正.

數(shù)據(jù)庫(kù)連接篇

在WEB項(xiàng)目里看到Web.config配置文件,在configuration這行加入下面代碼用于和SQL服務(wù)器進(jìn)行連接

<appSettings>
<!-- 數(shù)據(jù)庫(kù)連接字符串 -->
<add key="ConnStr" value="Data Source=localhost;database=company;UID=sa;Password=;Persist Security Info=True;" />
</appSettings>

數(shù)據(jù)列表顯示篇,如圖:

using System;
using System.Data;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

//引用命名空間:SQL托管,配置文件
using System.Data.SqlClient;
using System.Configuration;


public partial class _Default : System.Web.UI.Page
{
    protected SqlConnection myconn = new SqlConnection(ConfigurationSettings.AppSettings["ConnectionString"]);
    //讀取web.config配置文件中的數(shù)據(jù)庫(kù)連接字符串,并連接到指定的數(shù)據(jù)庫(kù)

    protected void Page_Load(object sender, EventArgs e)
    {
        if(!IsPostBack)//判斷頁(yè)面是否第一次運(yùn)行
     {

          string strsql="select * from Product";//定義一個(gè)數(shù)據(jù)庫(kù)的查詢(xún)字符串
                DataSet ds = new DataSet();
                myconn.Open();//打開(kāi)數(shù)據(jù)庫(kù)連接
                SqlDataAdapter command = new SqlDataAdapter(strsql,myconn);//表示用于填充DataSet 和更新SQL Server 數(shù)據(jù)庫(kù)的一組數(shù)據(jù)命令和一個(gè)數(shù)據(jù)庫(kù)連接
                command.Fill(ds, "Product");
                productList.DataSource = ds.Tables[0].DefaultView;
                productList.DataBind();
                ds.Clear();
          myconn.Close();//關(guān)閉數(shù)據(jù)庫(kù)連接
            }
 }

    protected void grid_ItemDataBound(object sender, DataGridItemEventArgs e)
    {
        foreach (System.Web.UI.WebControls.HyperLink link in e.Item.Cells[7].Controls)
        {
            link.Attributes.Add("onClick", "if (!window.confirm('您真的要?jiǎng)h除這條記錄嗎?')){return false;}");
        }
    }

}

數(shù)據(jù)添加篇

protected void btnAdd_Click(object sender, EventArgs e)
    {
        string ProductId = this.txtProductId.Text;
        string CategoryId = this.txtCategoryId.Text;
        string Name = this.txtName.Text;
        string Description = this.txtDescription.Text;
        string Price =this.txtPrice.Text;

        string sql_Exeits = "select * from Product where ProductId='" + ProductId + "'";
        SqlCommand cmd_Exeits = new SqlCommand(sql_Exeits, myconn);
        myconn.Open();
        SqlDataReader rdr = cmd_Exeits.ExecuteReader();
        while (rdr.Read())
        {
            Response.Write("<script language='JavaScript'>");
            Response.Write("alert('對(duì)不起,該產(chǎn)品編號(hào)已經(jīng)存在!')");
            Response.Write("</script>");
            this.txtCategoryId.Text = "";
            this.txtDescription.Text = "";
            this.txtName.Text = "";
            this.txtPrice.Text = "";
            this.txtProductId.Text = "";
            return;
        }
        rdr.Close();


        string sql_add = "insert into Product(ProductId,CategoryId,Name,Description,Price)values('" + ProductId + "','" + CategoryId + "','" + Name + "','" + Description + "','" + Price + "')";
        SqlCommand cmd_add = new SqlCommand(sql_add, myconn);//SqlCommand:表示要對(duì)SQL Server數(shù)據(jù)庫(kù)執(zhí)行的一個(gè)Transact-SQL語(yǔ)句或存儲(chǔ)過(guò)程
        cmd_add.ExecuteNonQuery();//對(duì)連接執(zhí)行Transact-SQL語(yǔ)句并返回受影響的行數(shù)。對(duì)于 UPDATE、INSERT 和 DELETE 語(yǔ)句,返回值為該命令所影響的行數(shù)。對(duì)于所有其他類(lèi)型的語(yǔ)句,返回值為 -1。如果發(fā)生回滾,返回值也為 -1。
        myconn.Dispose();
        myconn.Close();
    }
[/CODE


[COLOR=Red]數(shù)據(jù)顯示篇[/COLOR]
[CODE]
protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            string id = Request.Params["id"];
            if (id == null || id.Trim() == "")
            {
                Response.Redirect("default.aspx");
                Response.End();
            }
            else
            {
                string sql_show = "select * from Product Where ProductId=" + id;
                SqlCommand cmd_show = new SqlCommand(sql_show, conn);
                conn.Open();
                SqlDataReader rd_show = cmd_show.ExecuteReader();//使用SqlDataReader對(duì)象讀取并返回一個(gè)記錄集
                shows.DataSource = rd_show;//指向數(shù)據(jù)源
                shows.DataBind();//綁定數(shù)據(jù)
                rd_show.Close();//關(guān)閉SqlDataReader
             }
         }
    }

數(shù)據(jù)修改篇

    protected void btnAdd_Click(object sender, EventArgs e)
    {
        string ProductId = this.lblProductId.Text;
        string CategoryId = this.txtCategoryId.Text;
        string Name = this.txtName.Text;
        string Description = this.txtDescription.Text;
        decimal Price = decimal.Parse(this.txtPrice.Text);

        string sql_edit = "update Product set CategoryId='" + CategoryId + "',Name='" + Name + "',Description='" + Description + "',Price='" + Price + "' where ProductId =" + ProductId;
        SqlCommand cmd_edit = new SqlCommand(sql_edit, conn);

        conn.Open();
        cmd_edit.ExecuteNonQuery();
        conn.Close();
        Response.Write("<script language=javascript>window.alert('保存成功!')</script>");
        Response.Redirect("show.aspx?id=" + ProductId);
    }

數(shù)據(jù)刪除篇

protected void Page_Load(object sender, EventArgs e)
    {
        if (!Page.IsPostBack)
        {
            string ProductId = Request.Params["id"];
            string sql_del = "delete from Product where ProductId=" + ProductId;
            SqlCommand cmd_del = new SqlCommand(sql_del, conn);
            conn.Open();
            cmd_del.ExecuteNonQuery();
            conn.Close();
            Response.Redirect("default.aspx");
        }
    }

 

例子下載

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