ASP Lecture 4 Installable Components

1
ASP Lecture 4Installable Components

• Collaboration Data Objects CDONTS
• Supported messaging (email)
• ActiveX Data Objects ADODB
• A COM interface to databases and other sources.
• Others
• Ad Rotator, Content Linking, Content Rotator,
  Counters, File Access, Page Counter, Permission
  Checker

2
ADO Active Data Objects

• ADODB.Connection to a data provider (db)
• ADODB.Recordset the records returned from a
  query (or a whole table)
• ADODB.Field a component in a recordset
• ADODB.Command an SQL statement that returns a
  recordset
• ADODB.Parameter holds parameters in an SQL
  statement
• ADODB.Error, ADODB.Property

3
Connection object

• A connection to the database. Can be used for
  more than one query.
• Properties
• ConectionTimeout
• CommandTimeout
• ConnectionString
• Methods
• Open
• Close

4
Creating a connection object(http//www.asp101.co
m/samples/database.asp)

• Set DataConn Server.CreateObject("ADODB.Connecti
  on")
• DataConn.ConnectionTimeout 15 'property
• DataConn.CommandTimeout 30 property
• Note, this has no connection to any data yet.
• DataConn.Open "DBQ" Server.MapPath("database.md
  b") "DriverMicrosoft Access Driver (.mdb)
  DriverId25 MaxBufferSize8192 Threads20",
  "username", "password"
• An Access database, database.mdb on the default
• directory. Fill in correct username and
  password

5
Recordset object

• Records in a query or table from the connection
• It must be opened to have anything in it
• Properties
• ActiveConnection the current data source
• Fields in the table
• BOF, EOF of the recordset
• Methods
• AddNew
• Delete
• MoveFirst, MoveNext, MoveLast
• Open, Close

6
Command object

• Not necessary (one can just type in when a
  recordset is opened), but a neat way to define
  and reuse commands
• Properties
• CommandText
• CommandType (adcmdText SQL, adcmdTable table
  name,
• Methods
• Execute

7
Example (http//www.asp101.com/samples/database.as
p)

• Set cmdDC Server.CreateObject("ADODB.Command")
• cmdDC.ActiveConnection DataConn
• cmdDC.CommandText "SELECT FROM sample WHERE
  (Sales " strLTorGT " " iCriteria ") ORDER
  BY " strSortBy strOrder ""
• cmdDC.CommandType 1
• Set rsDC Server.CreateObject("ADODB.Recordset")
• rsDC.Open cmdDC, , 0, 1
• ' Open record set with a forward-only cursor ( 0)
  in read-only mode (1)
• Note, we could have typed in the command
• Review rest of the example

8
File Access

• Access to a file system via the FileSystemObject
• Server.CreateObject(Scripting.FileSystemObject)
  
• File system has folders, drives, files
• Methods CreateFolder, CreateTextFile,
  DriveExists, DeleteFile, GetFile, OpenTextFile,
  ...
• Text file methods Read, ReadLine, Write,
• Examples
• http//www.asp101.com/samples/counter.asp
• http//www.asp101.com/samples/modified.asp
• http//www.asp101.com/samples/textfile.asp