DataAccess

This is a  Simple  article which uses the DataGrid and Explains the DataAccess Mechanisms.

 

Simple DataAccessing startegies like

1. Data Insertion.
2. Data Searching and Data Modification .

This  uses the Reference Concepts in modifying the Data which matches the Search Criteria.

 

Application Logic and Presentation logic has been given separately.

 

3 DataGrids are given in  Presentation Logic.

• DataGrid1 BindGrids to the Default Contents of the table Data.
• DataGrid2 Inserted Data.
• Data Grid3 shows the searched and the modified Data.

Each Functionality is written under the Event of the Corresponding click Events  of the Button.

Application Logic

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.Data.OleDb;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
namespace DataGridUpdate {
    /// <summary>
    /// Summary description for WebForm1.
    /// </summary>
    public class WebForm1: System.Web.UI.Page {
        protected System.Web.UI.WebControls.Button Button1;
        protected System.Web.UI.WebControls.Button Button2;
        protected System.Web.UI.WebControls.Button Button3;
        protected System.Web.UI.WebControls.DataGrid DataGrid1;
        protected System.Web.UI.WebControls.DataGrid DataGrid2;
        protected System.Web.UI.WebControls.DataGrid DataGrid3;
        protected System.Web.UI.WebControls.Label Label1;
        protected System.Web.UI.WebControls.Label Label2;
        protected System.Web.UI.WebControls.Label Label3;
        protected System.Web.UI.WebControls.Label Label4;
        public OleDbDataAdapter odap;
        public OleDbConnection Con;
        protected System.Web.UI.WebControls.TextBox TextBox1;
        protected System.Web.UI.WebControls.Label Label5;
        public DataSet data;
        private void Page_Load(object sender, System.EventArgs e) {
            // Put user code to initialize the page here
            BindGrid();
        }
        #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.Button2.Click += new System.EventHandler(this.Button2_Click);
            this.Load += new System.EventHandler(this.Page_Load);
        }
        #endregion
        public void BindGrid() {
            Con = new OleDbConnection(@ "Provider=Microsoft.Jet.OleDb.4.0;Data Source =c:\robert\Emp.mdb");
            odap = new OleDbDataAdapter("select * from emp", Con);
            data = new DataSet();
            odap.Fill(data, "emp");
            DataGrid1.DataSource = data.Tables[0];
            DataGrid1.DataBind();
        }
        private void Button1_Click(object sender, System.EventArgs e) {
            DataTable table = data.Tables[0];
            DataRow row = null;
            row = table.NewRow();
            row[0] = 65;
            row[1] = "Kumar";
            row[2] = 125655;
            table.Rows.Add(row);
            DataGrid2.DataSource = table;
            DataGrid2.DataBind();
        }
        private void Button2_Click(object sender, System.EventArgs e) {
            DataTable table = data.Tables[0];
            string Qstr = "empid ='" + TextBox1.Text.Trim() + "'";
            DataRow[] row = table.Select(Qstr);
            foreach(DataRow r in row) {
                // Iam Modifying only the retrieved Content this is automatically reflected in the DataSource table;
                r[1] = "Ajith";
                r[2] = 787879;
            }
            DataGrid3.DataSource = table;
            DataGrid3.DataBind();
        }
    }
}

Presentation Logic 

<%@ Page language="c#" Codebehind="WebForm1.aspx.cs" AutoEventWireup="false" Inherits="DataGridUpdate.WebForm1" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
    <HEAD>
        <title>WebForm1</title>
        <meta name="GENERATOR" Content="Microsoft Visual Studio .NET 7.1">
            <meta name="CODE_LANGUAGE" Content="C#">
                <meta name="vs_defaultClientScript" content="JavaScript">
                    <meta name="vs_targetSchema" content="http://schemas.microsoft.com/intellisense/ie5">
                    </HEAD>
                    <body MS_POSITIONING="GridLayout">
                        <form id="Form1" method="post" runat="server">
                            <asp:Button id="Button1" style="Z-INDEX: 101; LEFT: 96px; POSITION: absolute; TOP: 600px" runat="server"

    Text="AddNewRow" Width="128px"></asp:Button>
                            <asp:Button id="Button2" style="Z-INDEX: 102; LEFT: 296px; POSITION: absolute; TOP: 600px"

     runat="server"

    Text="Edit Row" Width="136px"></asp:Button>
                            <asp:Button id="Button3" style="Z-INDEX: 103; LEFT: 504px; POSITION: absolute; TOP: 600px"

     runat="server"

    Text="Refresh" Width="144px"></asp:Button>
                            <asp:DataGrid id="DataGrid1" style="Z-INDEX: 104; LEFT: 96px; POSITION: absolute; TOP: 192px"

    runat="server"></asp:DataGrid>
                            <asp:DataGrid id="DataGrid2" style="Z-INDEX: 105; LEFT: 408px; POSITION: absolute; TOP: 192px"

    runat="server"></asp:DataGrid>
                            <asp:DataGrid id="DataGrid3" style="Z-INDEX: 106; LEFT: 704px; POSITION: absolute; TOP: 200px"

    runat="server"></asp:DataGrid>
                            <asp:Label id="Label1" style="Z-INDEX: 107; LEFT: 368px; POSITION: absolute; TOP: 16px" runat="server"

    Width="408px" Height="32px" Font-Size="Medium">Implementing DataGrid Action From Application

     Logic</asp:Label>
                            <asp:Label id="Label2" style="Z-INDEX: 108; LEFT: 112px; POSITION: absolute; TOP: 136px" runat="server"

    Width="147px">Existing Data</asp:Label>
                            <asp:Label id="Label3" style="Z-INDEX: 109; LEFT: 416px; POSITION: absolute; TOP: 144px" runat="server"

    Width="136px">Added Row Data</asp:Label>
                            <asp:Label id="Label4" style="Z-INDEX: 110; LEFT: 712px; POSITION: absolute; TOP: 144px" runat="server"

    Width="136px">Edited Row Data</asp:Label>
                            <asp:TextBox id="TextBox1" style="Z-INDEX: 111; LEFT: 656px; POSITION: absolute; TOP: 512px"

    runat="server" Width="104px" Height="24px"></asp:TextBox>
                            <asp:Label id="Label5" style="Z-INDEX: 112; LEFT: 272px; POSITION: absolute; TOP: 528px" runat="server"

    Width="225px" Height="16px">Enter Employee ID For Search</asp:Label>
                        </form>
                    </body>
                </HTML>

Application Logic

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.Data.OleDb;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
namespace DataGridUpdate {
    /// <summary>
    /// Summary description for WebForm1.
    /// </summary>
    public class WebForm1: System.Web.UI.Page {
        protected System.Web.UI.WebControls.Button Button1;
        protected System.Web.UI.WebControls.Button Button2;
        protected System.Web.UI.WebControls.Button Button3;
        protected System.Web.UI.WebControls.DataGrid DataGrid1;
        protected System.Web.UI.WebControls.DataGrid DataGrid2;
        protected System.Web.UI.WebControls.DataGrid DataGrid3;
        protected System.Web.UI.WebControls.Label Label1;
        protected System.Web.UI.WebControls.Label Label2;
        protected System.Web.UI.WebControls.Label Label3;
        protected System.Web.UI.WebControls.Label Label4;
        public OleDbDataAdapter odap;
        public OleDbConnection Con;
        protected System.Web.UI.WebControls.TextBox TextBox1;
        protected System.Web.UI.WebControls.Label Label5;
        public DataSet data;
        private void Page_Load(object sender, System.EventArgs e) {
            // Put user code to initialize the page here
            BindGrid();
        }
        #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.Button2.Click += new System.EventHandler(this.Button2_Click);
            this.Load += new System.EventHandler(this.Page_Load);
        }
        #endregion
        public void BindGrid() {
            Con = new OleDbConnection(@ "Provider=Microsoft.Jet.OleDb.4.0;Data Source =c:\robert\Emp.mdb");
            odap = new OleDbDataAdapter("select * from emp", Con);
            data = new DataSet();
            odap.Fill(data, "emp");
            DataGrid1.DataSource = data.Tables[0];
            DataGrid1.DataBind();
        }
        private void Button1_Click(object sender, System.EventArgs e) {
            DataTable table = data.Tables[0];
            DataRow row = null;
            row = table.NewRow();
            row[0] = 65;
            row[1] = "Kumar";
            row[2] = 125655;
            table.Rows.Add(row);
            DataGrid2.DataSource = table;
            DataGrid2.DataBind();
        }
        private void Button2_Click(object sender, System.EventArgs e) {
            DataTable table = data.Tables[0];
            string Qstr = "empid ='" + TextBox1.Text.Trim() + "'";
            DataRow[] row = table.Select(Qstr);
            foreach(DataRow r in row) {
                // Iam Modifying only the retrieved Content this is automatically reflected in the DataSource table;
                r[1] = "Ajith";
                r[2] = 787879;
            }
            DataGrid3.DataSource = table;
            DataGrid3.DataBind();
        }
    }
}

Presentation Logic

<%@ Page language="c#" Codebehind="WebForm1.aspx.cs" AutoEventWireup="false" Inherits="DataGridUpdate.WebForm1" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
    <HEAD>
        <title>WebForm1</title>
        <meta name="GENERATOR" Content="Microsoft Visual Studio .NET 7.1">
            <meta name="CODE_LANGUAGE" Content="C#">
                <meta name="vs_defaultClientScript" content="JavaScript">
                    <meta name="vs_targetSchema" content="http://schemas.microsoft.com/intellisense/ie5">
                    </HEAD>
                    <body MS_POSITIONING="GridLayout">
                        <form id="Form1" method="post" runat="server">
                            <asp:Button id="Button1" style="Z-INDEX: 101; LEFT: 96px; POSITION: absolute; TOP: 600px" runat="server"

    Text="AddNewRow" Width="128px"></asp:Button>
                            <asp:Button id="Button2" style="Z-INDEX: 102; LEFT: 296px; POSITION: absolute; TOP: 600px"

     runat="server" Text="Edit Row" Width="136px"></asp:Button>
                            <asp:Button id="Button3" style="Z-INDEX: 103; LEFT: 504px; POSITION: absolute; TOP: 600px"

     runat="server"  Text="Refresh" Width="144px"></asp:Button>
                            <asp:DataGrid id="DataGrid1" style="Z-INDEX: 104; LEFT: 96px; POSITION: absolute; TOP: 192px"

    runat="server"></asp:DataGrid>
                            <asp:DataGrid id="DataGrid2" style="Z-INDEX: 105; LEFT: 408px; POSITION: absolute; TOP: 192px"

    runat="server"></asp:DataGrid>
                            <asp:DataGrid id="DataGrid3" style="Z-INDEX: 106; LEFT: 704px; POSITION: absolute; TOP: 200px"

    runat="server"></asp:DataGrid>
                            <asp:Label id="Label1" style="Z-INDEX: 107; LEFT: 368px; POSITION: absolute; TOP: 16px" runat="server"

    Width="408px" Height="32px" Font-Size="Medium">Implementing DataGrid Action From Application

     Logic</asp:Label>
                            <asp:Label id="Label2" style="Z-INDEX: 108; LEFT: 112px; POSITION: absolute; TOP: 136px" runat="server"

    Width="147px">Existing Data</asp:Label>
                            <asp:Label id="Label3" style="Z-INDEX: 109; LEFT: 416px; POSITION: absolute; TOP: 144px" runat="server"

    Width="136px">Added Row Data</asp:Label>
                            <asp:Label id="Label4" style="Z-INDEX: 110; LEFT: 712px; POSITION: absolute; TOP: 144px" runat="server"

    Width="136px">Edited Row Data</asp:Label>
                            <asp:TextBox id="TextBox1" style="Z-INDEX: 111; LEFT: 656px; POSITION: absolute; TOP: 512px"

    runat="server" Width="104px" Height="24px"></asp:TextBox>
                            <asp:Label id="Label5" style="Z-INDEX: 112; LEFT: 272px; POSITION: absolute; TOP: 528px" runat="server"

    Width="225px" Height="16px">Enter Employee ID For Search</asp:Label>
                        </form>
                    </body>
                </HTML>