count

besides  $DBI::rows, $DBI::err, $DBI::errstr, any other useful functions of DBI?
where can I get more information of these useful functions?

In case you mean MetaData, well here are some methods used to obtain Meta Data:

$dbh->tables()
fetch a list of all accessible table names

$DBI::rows
The number of rows affected or returned

After executing the statement, use the statement handle to get:

$sth->{NUM_FIELDS}
The number of fields returned by a select

$sth->{NUM_PARAMS}
The number of parameters returned by any query

After a select query, the following attributes contain references to arrays of field-specific information:

$sth->{NAME}
Column names returned by the query

$sth->{NULLABLE}
Booleans indicating whether fields are nullable or not

$sth->{TYPE}
Field types

$sth->{PRECISION}
Floating-point precision of field

$sth->{SCALE}
Field lengths

thanks yovavm,

i would like to learn more about DBI?

do u know any good resources of DBI?

Check: "Advanced Perl Programming", By Sriram Srinivasan, published by O'Reilly & Associates.