Example 7 16   MySQL database connection with the Mysql.pm interface

use Mysql;

my $host="localhost";

my $database="itsodb";

my $user="itsosj";

my $password="itsosj";

$dbh = Mysql >connect($host,$database,$password,$user);

The corresponding DBI connection to a DB2 database is quite similar. Instead of 

the 

use Mysql

, the DBI interface and the DBD::DB2 driver have to be defined. If 

DB2 constants are used (e.g. SQL_MODE_READ_ONLY in the connection 

attributes, etc.) this has to be announced to the Perl interpreter by including 

 use 

DBD::DB2::Constants 

 in the Perl program (see Example 7 17).

Example 7 17   DB2 database connection with DBI interface

use DBI;

use DBD::DB2::Constants;

use DBD::DB2;

my $user="itsosj";

my $password="itsosj";

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

As DB2 is more powerful than MySQL, the connect statement may require a 

fourth argument 

\%attr

 which contains the connection attributes as shown in 

Example 7 18.

$dbh=DBI >connect($data_source, $user,$password, \%attr)

;

Example 7 18   DB2 specific connection attributes

db2_access_mode      SQL_MODE_READ_ONLY or SQL_MODE_READ_WRITE

db2_clischema        Character string

db2_close_behavior   SQL_CC_NO_RELEASE or SQL_CC_RELEASE

db2_connect_node     Integer (must be set in DBI >connect method; it cannot be 

 modified afterwards)

db2_current_schema   Character string

db2_db2estimate      Integer

db2_db2explain       One of:

                         SQL_DB2EXPLAIN_OFF

                         SQL_DB2EXPLAIN_SNAPSHOT_ON

                         SQL_DB2EXPLAIN_MODE_ON

                         SQL_DB2EXPLAIN_SNAPSHOT_MODE_ON

db2_info_acctstr     Character string

db2_info_applname    Character string

db2_info_userid      Character string

 Chapter 7. Application porting 

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