ASP.NET入门数据篇

数据添加篇

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('对不起，该产品编号已经存在！')");
            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:表示要对SQL Server数据库执行的一个Transact-SQL语句或存储过程
        cmd_add.ExecuteNonQuery();//对连接执行Transact-SQL语句并返回受影响的行数。对于 UPDATE、INSERT 和 DELETE 语句，返回值为该命令所影响的行数。对于所有其他类型的语句，返回值为 -1。如果发生回滚，返回值也为 -1。
        myconn.Dispose();
        myconn.Close();
    }

数据显示篇

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对象读取并返回一个记录集
                shows.DataSource = rd_show;//指向数据源
                shows.DataBind();//绑定数据
                rd_show.Close();//关闭SqlDataReader
             }
         }
    }

数据修改篇

    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);
    }

数据删除篇

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");
        }
    }