A Little Trouble Understanding About Primary Keys

Mar 24, 2006

Hi,

I have a couple of questions regarding primary keys, and whether I really need one or not.

Right now, I am using a GridView control to display all the data in my Access database, but am using a SqlDataSource control to do it. Everything works fine, and I am also using the GridView to Edit/Delete records, and I am using a DetailsView control to insert new records into the database.

The questions I have are these:

1) What I have right now in the database is a value called ID, which is just an autonumber, which has the order of the database, but I would like to change it so that the database sorts by the date awarded, which is a field in the database called "mdate", and make it so that when an admin enters a new date, it sorts automatically by date. Because of that, I am not really sure if I need to have the ID value at all.

I dont understand if it will be of any use, if I want all the values to show up by date, starting from 2006 back. If anyone can explain, or tell me if I am thinking correctly?

2) Also, right now in the database, the clients who started the database inserted the values in the "mdate" field as "Awarded mm/dd/year" instead of just "mm/dd/year".

How could I write a function to go through each record in the "mdate" column, delete the word "Awarded " and then convert it into a datetime object, so I could sort it by date? Is it possible, or would I have to do it manually?

Here is the code I have now:

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >

<head runat="server">

<title>Untitled Page</title>

</head>

<body>

<form id="form1" runat="server">

<div>

<asp:DetailsView ID="DetailsView1" runat="server" AllowPaging="True" DataSourceID="myDataSource1"

Height="50px" Width="300px" OnPageIndexChanging="DetailsView1_PageIndexChanging" Font-Names="Arial" Font-Size="Smaller">

<Fields>

<asp:CommandField ShowDeleteButton="True" ShowEditButton="True" ShowInsertButton="True" />

</Fields>

</asp:DetailsView>

<br />

&nbsp;</div>

<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="false" Font-Names="Verdana" AutoGenerateEditButton="True" AutoGenerateDeleteButton="true" DataSourceID="myDataSource1" DataKeyNames="ID">

<Columns>

<asp:BoundField HeaderText = "ID" DataField="ID" ReadOnly="true" Visible="false" />

<asp:BoundField HeaderText = "Name" DataField="name" />

<asp:BoundField HeaderText = "Department Retired From" DataField="dept" />

<asp:BoundField HeaderText = "Current State Of Residence" DataField="state" />

<asp:BoundField HeaderText = "Purpose Of Award" DataField="award" />

<asp:BoundField HeaderText = "Date Awarded" DataField="mdate" />

</Columns>

<RowStyle Font-Size="Smaller" Height="50px" HorizontalAlign="Center" />

</asp:GridView>

<asp:SqlDataSource ID="myDataSource1" runat="server" SelectCommand = "SELECT * from [finawards]" ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0; Data Source=|DataDirectory|finawards_new.mdb" ProviderName="System.Data.OleDb" UpdateCommand = "UPDATE [finawards] SET [name] = @name, [dept] = @dept, [state] = @state, [award] = @award, [mdate] = @mdate WHERE [ID] = @ID" DeleteCommand = "DELETE FROM finawards WHERE [ID] = @ID" InsertCommand = "INSERT INTO finawards (name, dept, state, award, mdate) VALUES (@name, @dept, @state, @award, @mdate)"></asp:SqlDataSource>

&nbsp;

</form>

</body>

</html>

Thanks,

 

 

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Hi,

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