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ADO

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Accessing a Database from an ASP Page

y The common way to access a database from inside an ASP page is

to:

y Create an ADO connection to a database

y Open the database connection

y Create an ADO recordset

y Open the recordset

y Extract the data you need from the recordset

y

Close the recordsety Close the connection

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What is ADO?y ADO can be used to access databases from your web pages.

y ADO is a Microsoft technology

y ADO stands for ActiveXDataObjects

y ADO is a Microsoft Active-X componenty ADO is automatically installed with Microsoft IIS

y ADO is a programming interface to access data in a database

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ADO Database Connectiony Before a database can be accessed from a web page, a database

connection has to be established.

y Create an ODBCDatabase Connection

y If you have an ODBC database called "northwind" you can

connect to the database with the following ASP code:y

y With an ODBC connection, you can connect to any database, on

any computer in your network, as long as an ODBC connection is

available.

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ADO Recordset

y Create an ADO Table Recordset

y After an ADO Database Connection has been created, it is possible

to create an ADO Recordset.

y

Suppose we have a database named "Northwind", we can getaccess to the "Customers" table inside the database with the

following lines:

y

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ADO Recordset

y Create an ADO SQL Recordset

y We can also get access to the data in the "Customers" table

using SQL:

y

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ADO Recordset

y Extract Data from the Recordset

y After a recordset is opened, we can extract data from recordset.y Suppose we have a database named "Northwind", we can get

access to the "Customers" table inside the database with the

following lines:

y

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Cont

ydo until rs.EOFfor each x in rs.Fields

Response.Write(x.name)

Response.Write(" = ")

Response.Write(x.value & "
")next

Response.Write("
")

rs.MoveNext

looprs.close

conn.close

%>

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Output Result

y CustomerID = 12345

CompanyName = ABC DEF

ContactName = MNO

Address = Obere Str. 57City = DELHI

PostalCode = 122365

Country = INDIA

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Demo_add.asp

y

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Demo_add.asp

y sql="INSERT INTO customers

(customerID,companyname,"

sql=sql & "contactname,address,city,postalcode,country)"

sql=sql & " VALUES "

sql=sql & "('" & Request.Form("custid") & "',"

sql=sql & "'" & Request.Form("compname") & "',"

sql=sql & "'" & Request.Form("contname") & "',"

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Demo_add.asp

y on error resume next

conn.Execute sql,recaffected

if err0 then

Response.Write("No update permissions!")

else

Response.Write("" & recaffected & " record

added")

end if

conn.close%>

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Updating Recordy sql="UPDATE customers SET "

y sql=sql & "companyname='"

&Request.Form("companyname") & "',

y sql=sql & "contactname='"

&Request.Form("contactname") & "',"

y sql=sql & "address='" & Request.Form("address") & "',"

y sql=sql & "city='" & Request.Form("city") & "',"

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Cont

y sql=sql & "postalcode='" & Request.Form("postalcode") &

"',"

sql=sql & "country='" & Request.Form("country") & "'"

sql=sql & " WHERE customerID='" & cid & "'"

on error resume next

conn.Execute sql

if err0 then

response.write("No update permissions!")

elseresponse.write("Record " & cid & " was updated!")

end if

end if

conn.close

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Deleting record

y

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Cont

y if err0 then

response.write("No update permissions!")

else

response.write("Record " & cid & " was deleted!")

end if

end if

conn.close

%>

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Recordset Object

y The ADO Recordset object is used to hold a set of records

from a database table. A Recordset object consist of records

and columns.

y

Syntax:y set

objRecordset=Server.CreateObject("ADODB.recordset")

y It supports 2 types of updation:

y Immediate updatingy Batch updating

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Properties

y Absolute Page:Sets or returns a value that specifies the page

number in the Recordset object.

y AbsolutePosition:Sets or returns a value that specifies the

ordinal position of the current record in the Recordset objecty Bookmark:Sets or returns a bookmark. The bookmark saves

the position of the current record.

y CacheSize:Sets or returns the number of records that can be

cached.y CursorLocation:Sets or returns the location of the cursor

service

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Cont

y EOF:Returns true if the current record position is after the

last record, otherwise false

y Filter

y

Indexy MaxRecords:Sets or returns the maximum number of

records to return to a Recordset object from a query.

y PageCount

y RecordCount

y PageSize

y Sort

y Status

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Methodsy AddNew

y Cancel

y CancelUpdate

y Close:Closes a Recordset

yMove

y MoveFirst

y MoveLast

y MoveNext

y MovePrevious

y Open

y Save

y

Seek,Update,UpdateB

atch

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Thanx!