使用 DataAdapter 和 DataSet 更新数据库

DataAdapter 的 Update 方法：将 DataSet 中的更改解析回数据源。DataSet保存的数据是位于服务器内存里面的原数据库的“副本”。所以用DataSet更新数据的过程就是先对“副本”进行更新，然后在将“原本”更新。

Update 方法会将更改解析回数据源，但是自上次填充 DataSet 以来，其他客户端可能已修改了数据源中的数据。若要使用当前数据刷新 DataSet，请再次使用 DataAdapter 填充 (Fill) DataSet。

EntityAA.cs

 1using System;
 2using System.Data;
 3using System.Data.SqlClient;
 4
 5namespace DataSetAdapter
 6{
 7    /**//// <summary>
 8    /// Summary description for EntityAA.
 9    /// </summary>
10    public class EntityAA
11    {
12        private string connstr = System.Configuration.ConfigurationSettings.AppSettings["connString"];
13        private SqlConnection conn;
14
15        private string sql;
16
17        private SqlDataAdapter adp;
18        private SqlCommandBuilder cb;
19
20        private DataSet ds;
21        private DataTable dt;
22
23        public EntityAA()
24        {
25            conn = new SqlConnection(connstr);
26            sql = "select * from aa";
27
28            adp = new SqlDataAdapter(sql,conn);
29            cb = new SqlCommandBuilder(adp);
30
31            ds = new DataSet();
32
33            FillDataSet();
34
35            dt = ds.Tables["table_aa"];
36
37            dt.PrimaryKey = new DataColumn[]{dt.Columns["a"]};
38        }
39        
40        private void FillDataSet()
41        {
42            conn.Open();
43            adp.Fill(ds,"table_aa");
44            conn.Close();
45        }
46
47        public DataSet List
48        {
49            get {return ds;}
50        }
51
52        public void insert(string c)
53        {
54            dt.Columns["a"].AutoIncrement = true;                        
55
56            DataRow dr = dt.NewRow();
57            dr["c"] = c;
58            dt.Rows.Add(dr);                //添加新行
59
60            adp.Update(ds,"table_aa");
61
62        }
63
64        public void up_date(int ids,string name)
65        {
66            DataRow dr = dt.Rows.Find(ids);        //获取由主键值指定的行
67            dr["c"] = name;                        //更新
68
69            adp.Update(ds,"table_aa");
70        }
71
72        public void del(int ids)
73        {
74            DataRow dr = dt.Rows.Find(ids);        //获取由主键值指定的行
75            dr.Delete();
76
77            adp.Update(ds,"table_aa");
78
79        }
80
81
82    }
83}
84

WebForm1.aspx.cs

using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;

namespace DataSetAdapter
{
    /**//// <summary>
    /// Summary description for WebForm1.
    /// </summary>
    public class WebForm1 : System.Web.UI.Page
    {
        protected System.Web.UI.WebControls.Label Label1;
        protected System.Web.UI.WebControls.Label Label2;
        protected System.Web.UI.WebControls.TextBox txt_a;
        protected System.Web.UI.WebControls.TextBox txt_c;
        protected System.Web.UI.WebControls.Button delete;
        protected System.Web.UI.WebControls.Button Button2;
        protected System.Web.UI.WebControls.DataGrid DataGrid1;
        protected System.Web.UI.WebControls.Button Button1;
    
        private void Page_Load(object sender, System.EventArgs e)
        {
            if(!this.Page.IsPostBack)
                BindGrid();
        }

        Web Form Designer generated code#region Web Form Designer generated code
        override protected void OnInit(EventArgs e)
        {
            //
            // CODEGEN: This call is required by the ASP.NET Web Form Designer.
            //
            InitializeComponent();
            base.OnInit(e);
        }
        
        /**//// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {    
            this.Button1.Click += new System.EventHandler(this.Button1_Click);
            this.delete.Click += new System.EventHandler(this.delete_Click);
            this.Button2.Click += new System.EventHandler(this.Button2_Click);
            this.Load += new System.EventHandler(this.Page_Load);

        }
        #endregion

        private void BindGrid()
        {
            EntityAA entityaa = new EntityAA();
            DataSet ds = entityaa.List;

            this.DataGrid1.DataSource = ds;
            this.DataGrid1.DataBind();
        }



        private void Button1_Click(object sender, System.EventArgs e)
        {
            int ids = Int32.Parse(this.txt_a.Text);
            string name = this.txt_c.Text;

            EntityAA entityaa = new EntityAA();
            entityaa.up_date(ids,name);

            BindGrid();
        }


        private void delete_Click(object sender, System.EventArgs e)
        {
            int ids = Int32.Parse(this.txt_a.Text);

            EntityAA entityaa = new EntityAA();
            entityaa.del(ids);

            BindGrid();
        }

        

        private void Button2_Click(object sender, System.EventArgs e)
        {
            string c = this.txt_c.Text;
            
            EntityAA entityaa = new EntityAA();
            entityaa.insert(c);

            BindGrid();
        }

        



    }
}