Table of Contents for

MySQL in a Nutshell, 2nd Edition

This statement handle method returns one row, the next from the results of an SQL statement in the form of an array, each of whose element is a field of data. Null values retrieved are returned as undefined. An empty value is returned when there is an error or when there are no more rows remaining in the results set. Therefore, if used in a flow control statement such as while, the empty value returned will end the loop statement. Here is an example:

...
my $sql_stmnt = "SELECT title, author FROM books";
my $sth = $dbh->prepare($sql_stmnt);
$sth->execute();

while (my ($title, $author) = $sth->fetchrow_array(){
   print "$title by $author \n";
}

$sth->finish();

If you know that the SQL statement will return only one row, you won’t need the while statement. Instead, you can save the values directly into a tight list of variables:

...
my $sql_stmnt = "SELECT title, author 
                 FROM books LIMIT 1";
my $sth = $dbh->prepare($sql_stmnt);
$sth->execute();

my ($title, $author) = $sth->fetchrow_array();

print "$title by $author \n";
...