Question

使用Perl和DBI从SQL数据库中获取数据。我使用下面的代码从表中获取数据。而不是定义3个不同的数组，有没有办法定义一个包含多个字段的数组？

$sql = "select * from tblPeople where PersonID=?";
$sth = $dbh->prepare($sql);
$sth->execute($PID);

while ($DRow = $sth->fetchrow_hashref) {
    push @KnownPIDs,  $DRow->{PersonID};
    push @Knownoss,   $DRow->{currentpos};
    push @Knownnotes, $DRow->{personnotes};
}

Answer 1

我会做的是使用DRow哈希的键作为新HoA哈希的键，并动态地使HoA的每个值成为一个数组。

#!/usr/bin/perl

use Data::Dumper;

my %HoA; # hash of arrays
my $DRow = {};

# set up some example data

$DRow->{PersonID} = 'steve';
$DRow->{currentpos} = 'one';
$DRow->{personnotes} = 'This is not my suicide note';

# by using a Hash of Arrays (HoA), we can dynamically build
# the entire structure without having to manually type everything 
# out for each row item

for my $key (keys(%{ $DRow })){
    push @{ $HoA{$key} }, $DRow->{$key};
}

# to access the 'PersonID' of say the third row that was processed:
# my $pid = $HoA{PersonID}->[2];

print Dumper \%HoA;

输出：

$VAR1 = {
          'personnotes' => [
                             'This is not my suicide note'
                           ],
          'PersonID' => [
                             'steve'
                        ],
          'currentpos' => [
                            'one'
                          ]
        };

Perl中的多字段数组

1 个答案: