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         Under  Windows

       Perl  as an interpreted language,  was originally developed
        to be   used  under   the  Unix  platform.  Its  ease of use 
        and    suitability    to    most   of   the   cgi   programming
        applications   has  made  it a viable alternative   under all 
        the platforms.   Hence  ports of Perl  has been written for 
        and documented under different platforms.
 

        The  Windows  Port  of  Perl  is  available  in  two different 
        flavours,  the native or the  standard  Perl and  the Active 
        Perl .   Both  of  them are commonly referred to as Perl for 
        Win32. (Note:  In this tutorial when i refer  to  Windows it 
        refers to Windows 95 as well as Windows NT).  The Active
        Perl  is a snap to install and has more  GUI   like  interface. 
        While in this  tutorial i discuss about the Active  Perl  as a 
        reference, i do not have any preferential choice  between 
        the Active or the Native flavours.

 
Downloading and installing  Perl

The   Active  version  of   Perl   is  well documented   and 
the    latest   build   as   of  this writing   is available as a
freeware   download    from http://www.activestate.com
The    installation   is  the  simplest process of all and any
Windows   aware    user  should  be able  to do that quite 
easily.
 

Enabling CGI access

No ..No..  i am  not explaining that. This is a slightly tricky
issue  and  explaining that  would extend the length   and 
make  me    to   divert  from  the  topic.  This  heading  is 
included   to    make     the  reader   aware that  it is one 
essential   part  to  make  an  interactive   communication 
possible with the web  server,   which  is the basis for  all
the   database   programming   over   the  web. Complete
documentation   is  available, which comes along with the 
Perl  download  and  it  could be referred for enabling  CGI
access with various Web Servers. Following this link would
also   help  you   access  the reference available from the
activestate site.    You can in addition use   this link,   in 
case you are using Microsoft Internet Information  Server
or Microsoft Personal Web Server.
 
 

The Database connectivity

To  establish  database    connectivity   you need to have
an  ODBC  compliant    database,   and a  Perl   extension 
that     provides    access     to   the   ODBC  Application 
Programming  Interface  (API) . Win32::ODBC is a   Perl 5 
extension   written   by Dave Roth and is   available  from
ftp.roth.net .   The  installation instructions   alone   are 
repeated  below  from  the  official page to Win32::ODBC
the  other     details   such  as   the      Sql  statements 
supported, Features,troubleshooting etc., can be had by 
clicking the link.
 
 

Installing  Win32::ODBC
 

1. Copy the ODBC.PM file into the \PERL\SITE\LIB\WIN32 
    directory. 

2. Copy     the    ODBC10x.PLL     file   into       the 
    \PERL\SITE\LIB\AUTO\WIN32\ODBC   directory.     This  is
    either ODBC105.PLL (for versions of Perl 105 or before) 
    or ODBC106.PLL    (for  versions  of Perl 106 or later), 
    renaming the correct file to ODBC.PLL (run "perl -v" to
    check which version of perl you have). 

After  successfully  installing  Win32::ODBC you need to
create a System  DSN.   Follow  these steps carefully to 
do it.
 

Creating a System DSN

1. Double-click the MyComputer Icon and then open the
    Control-Panel on your system.

2. Locate the ODBC Manger icon and double-click on it.
    The icon looks like this 32 bit ODBC Manager icon

3. Click the   System DSN tab and click  Add. You will 
    be prompted to select the ODBC driver, that you will
    be using, from the list of available drivers. If your 
    database is MS-Access then choose the Microsoft 
    Access Driver(*.mdb)  or choose the suitable driver 
    according to your database. This is followed by a dialog 
    box asking you to enter the DataSource Name (DSN). 
    Type in any applicable name. This is the name you will 
    be  using in your programs to talk with your database. 
    This should be unique. Then select the database to 
    associate with this Datasource.

4. If  you   require  you can also  give  a username and 
    password to connect to the Datasource by choosing the 
    Advanced tab.

5. This completes the successful creation of a System DSN.
 
 

Now moving on to some real programming.  I'll  explain an example
code that should be enough to keep you get going. 

Consider a situation where you would like to query a database 
for the Author's name  and price of the book titled "CGI Programming 
with Perl". 

1. use Win32::ODBC;
2. $db=new WIN32::ODBC('simple');
3. $varname="CGI Programming with Perl";
4. $db->Sql("select aname,price from  mytable where 
                   book='$varname' ");
5. $db->FetchRow();
6. ($Author,$cost)=$db->Data("aname","price");
7. print  "The Book titled $varname is written by $Author 
   and costs  $cost";
 

Line 1:  Instruction to the Perl Interpreter to include the package 
            Win32::ODBC.

Line 2:  Creates a database handle to the Datasource  'simple'.

Line 3:  Assigns the title of the book to the variable '$varname'.

Line 4:  Passes a SQL Query to the table 'mytable' through the 
            handle '$db'.

Line 5:  Fetches the First row of record that matches the Query.

Line 6:  Assigns the value of the fields 'aname' (Author name) 
            and 'price' to the variables  $Author and $cost respectively. 

Line 7:  Prints the Result successfully.
 
 

Hope that was easy enough.  Let us proceed to see , how the same is implemented under the unix platform.
 

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