1. Mark Dixon, SoCCE SOFT 131Page 1 24 – Web applications: Writing data to Databases using ASP

2. Mark Dixon, SoCCE SOFT 131Page 2 Admin Module Feedback Questionnaire in general feedback should be: –specific & detailed enough to take action –timely enough to take action Most effective feedback: –informal comments from students during/after tutorials/lectures

3. Mark Dixon, SoCCE SOFT 131Page 3 Session Aims & Objectives Aims –To introduce the fundamental ideas involved in using server-side code to write data to databases Objectives, by end of this week’s sessions, you should be able to: –create an ASP web page that allows the user to store data in database

4. Mark Dixon, SoCCE SOFT 131Page 4 Database Permissions 1 In order for ASP to write to a database –Need to give write access to Internet Guest Account for database file (People.mdb) Right-click on file in Windows Explorer (the following screens are for Windows 2000)

5. Mark Dixon, SoCCE SOFT 131Page 5 Database Permissions 2 Click Security tab Click Add button

6. Mark Dixon, SoCCE SOFT 131Page 6 Database Permissions 3 Select Internet Guest Account IUSR_ … Click Add button Click OK button

7. Mark Dixon, SoCCE SOFT 131Page 7 Database Permissions 4 Select Internet Guest Account Ensure write access is on

8. Mark Dixon, SoCCE SOFT 131Page 8 Writing data to a database create recordset open recordset –dynamic cursor, pessimistic locking to add a record –use to AddNew method rs.AddNew to delete a record –use the Delete method rs.Delete to change existing data –assign a new value to fields rs.Fields("Surname").Value = "Fred"

9. Mark Dixon, SoCCE SOFT 131Page 9 Example: Person Edit (html) Person's Details Person's Details <% ' ASP code will go here (next slide). %> Surname: " > PersonEdit.asp

10. Mark Dixon, SoCCE SOFT 131Page 10 Example: Person Edit (ASP) <% Const cs = "…" Dim rs Dim Surname Set rs = CreateObject("ADODB.Recordset") rs.Open "Person", cs, 3, 3 If Session("curID") <> "" Then rs.Find "[ID] = " & Session("curID") If Request.Form("btnPrev") <> "" Then rs.MovePrevious ElseIf Request.Form("btnNext") <> "" Then rs.MoveNext ElseIf Request.Form("btnSave") <> "" Then rs. Fields("Surname") = Request.Form("txtSurname") rs. Update End If Session("curID") = rs.Fields("ID").Value Surname = rs.Fields("Surname").Value rs.Close Set rs = Nothing %>

11. Mark Dixon, SoCCE SOFT 131Page 11 Include files web pages –mix HTML, VB Script, and SQL can become messy use include files to –modularise (break up) code

12. Mark Dixon, SoCCE SOFT 131Page 12 Example: People.asp Personal Address Book Personal Address Book <% Const cs = " … … " Dim rs Set rs = CreateObject("ADODB.Recordset") rs.Open "Person", cs Do Until rs.EOF Response.Write rs.Fields("Surname").Value Response.Write " " rs.MoveNext Loop rs.Close Set rs = Nothing %>

13. Mark Dixon, SoCCE SOFT 131Page 13 Example: People2.asp People2.asp Personal Address Book Personal Address Book <% Const cs = " … … " Dim rs Set rs = CreateObject("ADODB.Recordset") rs.Open "Person", cs Do Until rs.EOF Response.Write rs.Fields("Surname").Value Response.Write " " rs.MoveNext Loop rs.Close Set rs = Nothing %> People.inc

14. Mark Dixon, SoCCE SOFT 131Page 14 Example: Procedures People3.asp Personal Address Book <!-- #include file ="People.inc" --> Personal Address Book <% ShowPeople %> People.inc <% Const cs = " … … " Sub ShowPeople () Dim rs Set rs = CreateObject("ADODB.Recordset") rs.Open "Person", cs Do Until rs.EOF Response.Write rs.Fields("Surname").Value Response.Write " " rs.MoveNext Loop rs.Close Set rs = Nothing End Sub %>

15. Mark Dixon, SoCCE SOFT 131Page 15 Example: Parameters People4.asp Personal Address Book <!-- #include file ="People2.inc" --> Personal Address Book <% if Request.Form("btnOrder") <> "" Then ShowPeople "SELECT * FROM Person ORDER BY Surname ASC" Else ShowPeople "Person" End If %> People.inc <% Const cs = “… …" Sub ShowPeople(strQuery) Dim rs Set rs = CreateObject("ADODB.Recordset") rs.Open strQuery, cs Do Until rs.EOF Response.Write rs.Fields("Surname").Value Response.Write " " rs.MoveNext Loop rs.Close Set rs = Nothing End Sub %> People4.asp