@arr = $sth >fetchrow_array;

The biggest difference is that in case of DBI, the statement first has to be 

prepared before it is executed. Two statements are needed for this functionality.

The MySQL code 

fetchrow

 and the respective DB2 code 

fetchrow_array

functions return the next row of data from the statement handle generated by the 

query

 or 

execute

 commands.

INSERT, UPDATE, and DELETE statements

Generally, the same functions can be used for the 

INSERT

, 

UPDATE

 and 

DELETE

statements as for the 

SELECT

 statement discussed above. For the non SELECT 

statement, DBI provides a faster substitute for 

DBI::prepare/DBI::execute

 pair 

with the 

DBI::do

 function:

$rows_affected = $dbh >do($sql_statement);

For further information, please refer to the DBI documentation previously.

Disconnecting database

The Mysql.pm interface does not provide a disconnect function, because MySQL 

does not support transactions yet. Whenever the database handle loses its 

value, Mysql.pm closes the database connection. However, databases that do 

support transactions need to be explicitly disconnected. The DBI interface 

supports the disconnect function for the database handle.

Example 7 21   Disconnecting DB2 database using DBI

use DBI;

use DBD::DB2::Constants;

use DBD::DB2;

my $user="itsosj";

my $password="itsosj";

$dbh = DBI >connect("dbi:DB2:itsodb2", $username, $password);

...

$dbh >disconnect;

7.2.2  Converting MySQL PHP applications to DB2 UDB

With PHP applications, different approaches can be used to access DB2:

iODBC with ODBC compliant drivers

iODBC is provided by OpenLink Software. iODBC is the acronym for 

Independent Open DataBase Connectivity, an Open Source platform 

 Chapter 7. Application porting 

177