1. User Defined Procedures

21 – Web applications:
Databases & ASP
Mark Dixon, SoCCE
SOFT 131
Page 1
Session Aims & Objectives
• Aims
– To introduce the fundamental ideas involved in
using server-side code to read data from
databases
• Objectives,
by end of this week’s sessions, you should be able to:
– create an ASP web page that displays data read
from a database
Mark Dixon, SoCCE
SOFT 131
Page 2
People Database
ID
1
2
3
4
5
Surname
Dixon
Smith
Jones
Bloggs
Anderson
Mark Dixon, SoCCE
Forenames
Mark
John
Sally
Fred
Genny
Phone
01752 232556
01752 111111
01752 888888
01752 123123
01752 987987
SOFT 131
email
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
Page 3
Example 1: People (html)
People.asp
<html>
<head>
<title>Personal Address Book</title>
</head>
<body>
<center>
Personal Address Book
</center>
<%
' ASP code will go here (next slide)
%>
</body>
</html>
Mark Dixon, SoCCE
SOFT 131
Page 4
Example 1: People (ASP)
<html>
<head><title>Personal Address Book</title></head>
<body>
<center>
Personal Address Book</center>
rs
<%
Const cs = "Provider=…;Data Source=D:\People.mdb; "
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
%>
ID
1
2
3
4
5
Surname
Dixon
Smith
Jones
Bloggs
Anderson
Forenames
Mark
John
Sally
Fred
Genny
Phone
01752 232556
01752 111111
01752 888888
01752 123123
01752 987987
email
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
</body>
</html>
Mark Dixon, SoCCE
SOFT 131
Page 5
Example 1: People (recordset 1)
<html>
<head><title>Personal Address Book</title></head>
<body>
<center>
Personal Address Book</center>
rs
<%
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
%>
ID
1
2
3
4
5
Surname
Dixon
Smith
Jones
Bloggs
Anderson
Forenames
Mark
John
Sally
Fred
Genny
Phone
01752 232556
01752 111111
01752 888888
01752 123123
01752 987987
email
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
Dixon
</body>
</html>
Mark Dixon, SoCCE
SOFT 131
Page 6
Example 1: People (recordset 2)
<html>
<head><title>Personal Address Book</title></head>
<body>
<center>
Personal Address Book</center>
rs
<%
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
%>
ID
1
2
3
4
5
Surname
Dixon
Smith
Jones
Bloggs
Anderson
Forenames
Mark
John
Sally
Fred
Genny
Phone
01752 232556
01752 111111
01752 888888
01752 123123
01752 987987
email
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
Dixon
Smith
</body>
</html>
Mark Dixon, SoCCE
SOFT 131
Page 7
Example 1: People (recordset 3)
<html>
<head><title>Personal Address Book</title></head>
<body>
<center>
Personal Address Book</center>
rs
<%
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
%>
ID
1
2
3
4
5
Surname
Dixon
Smith
Jones
Bloggs
Anderson
Forenames
Mark
John
Sally
Fred
Genny
Phone
01752 232556
01752 111111
01752 888888
01752 123123
01752 987987
email
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
Dixon
Smith
Jones
</body>
</html>
Mark Dixon, SoCCE
SOFT 131
Page 8
Example 1: People (recordset 4)
<html>
<head><title>Personal Address Book</title></head>
<body>
<center>
Personal Address Book</center>
rs
<%
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
%>
ID
1
2
3
4
5
Surname
Dixon
Smith
Jones
Bloggs
Anderson
Forenames
Mark
John
Sally
Fred
Genny
Phone
01752 232556
01752 111111
01752 888888
01752 123123
01752 987987
email
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
Dixon
Smith
Jones
Bloggs
</body>
</html>
Mark Dixon, SoCCE
SOFT 131
Page 9
Example 1: People (recordset 5)
<html>
<head><title>Personal Address Book</title></head>
<body>
<center>
Personal Address Book</center>
People.asp
rs
<%
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
%>
ID
1
2
3
4
5
Surname
Dixon
Smith
Jones
Bloggs
Anderson
Forenames
Mark
John
Sally
Fred
Genny
Phone
01752 232556
01752 111111
01752 888888
01752 123123
01752 987987
email
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
Dixon
Smith
Jones
Bloggs
Anderson
</body>
</html>
Mark Dixon, SoCCE
SOFT 131
Page 10
Example 2: Person (html)
<html>
<head>
<title>Person's Details</title>
</head>
<body>
<center>Person's Details</center>
<%
' ASP code will go here (next slide).
%>
Person.asp
<form name="frmPerson" action="Person.asp" method=post>
<input name="btnPrev" type="submit" value="Previous">
<input name="btnNext" type="submit" value="Next">
</form>
</body>
</html>
Mark Dixon, SoCCE
SOFT 131
Page 11
Example 2: Person (ASP)
<%
Const adOpenDynamic = 3
Const cs = "…"
Dim rs
Set rs = CreateObject("ADODB.Recordset")
rs.Open "Person", cs, adOpenDynamic
If Session("curID") <> "" Then
rs.Find "[ID] = " & Session("curID")
If Request.Form("btnPrev") <> "" Then
rs.MovePrevious
ElseIf Request.Form("btnNext") <> "" Then
rs.MoveNext
End If
End If
Session("curID") = rs.Fields("ID").Value
Response.Write rs.Fields("Surname").Value & " "
Response.Write rs.Fields("Forenames").Value
rs.Close
Set rs = Nothing
%>
Mark Dixon, SoCCE
SOFT 131
Page 12
SQL
• Structured Query Language
• 4th Generation Language
– code describes what (not how)
– (VB 3rd Generation)
• SELECT statement
– used to get data
– can be embedded in VB, via rs.Open:
all fields
rs.Open "Person", cs
rs.Open "SELECT * FROM [Person]", cs
Mark Dixon, SoCCE
SOFT 131
Page 13
SQL
• WHERE clause
– used to restrict data
SELECT * FROM [People] WHERE [age]>=18;
• ORDER BY clause
– used to change order of data
SELECT * FROM [People] ORDER BY [Surname];
Mark Dixon, SoCCE
SOFT 131
Page 14

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