對行陣列的參考進行排序，其中每一行都存盤為散列

我正在嘗試通過 location_id 對 Perl 中的以下資料結構進行排序。

my $employees = $dbh->selectall_arrayref(qq[
    SELECT name, type, code, emp_cat_id,
           percentage, location_id
    FROM table_1
],{ Slice => {} });
 
for my $row (@$employees) {
   push @{
      $args->{employees}{ $row->{emp_cat_id} }
   }, $row;
}

例子：

123 => [
   {
      percentage  => 0.25,
      code        => "XYZ",
      name        => "John Doe",
      type        => "pt",
      location_id => 001,
      emp_cat_id  => 123

   }
],
555 => [
   {
      percentage  => 0.50,
      code        => "ZZZ"
      name        => "Chris Cringle",
      type        => "ft",
      location_id => 007,
      emp_cat_id  => 555

   },
   {
      percentage  => 0.25,
      code        => "XXX"
      name        => "Tom Thompson",
      type        => "pt",
      location_id => 002,
      emp_cat_id  => 555

   }
]

對于每個 emp_cat_id，我需要結構以 asc 順序包含 location_ids。

我已經嘗試了以下操作，但是我得到了“在第 # 行的無效背景關系中無用使用排序”或“在 # 行在標量背景關系中無用使用排序”錯誤。

$args->{employees} = sort {
   $a->{location_id} <=> $b->{location_id}
} $args->{employees};

任何幫助理解排序表示贊賞！

uj5u.com熱心網友回復：

問題是您在emp_cat_idof和555of處對陣列（ref）123進行排序，因此需要取消參考以對這些陣列參考進行排序。所以

foreach my $id (keys $args->{employees}) { 
    @{ $args->{employees}{$id} } = sort { 
            $a->{location_id} <=> $b->{location_id} 
        }
        @{ $args->{employees}{$id} } 
}

（使用問題中顯示的結構進行測驗，此處省略）^?

做這樣的事失去007進入7。這當然可以解決，如果這很重要，請告訴我。

如果您真的只有密鑰，請employees考慮提取$args->{employees}hashref 并使用它。會容易很多

use Storable qw(dclone);

my $employees = dclone $args->{employees};  # need deep copy

^?哦，這就是整件事

use warnings;
use strict;
use feature 'say';
use Data::Dump qw(dd);

my $args = {
    employees => {
        123 => [
            {
                percentage  => 0.25,
                code        => "XYZ",
                name        => "John Doe",
                type        => "pt",
                location_id => 001,
                emp_cat_id  => 123
            }
        ],
        555 => [
            {
                percentage  => 0.50,
                code        => "ZZZ",
                name        => "Chris Cringle",
                type        => "ft",
                location_id => 007,
                emp_cat_id  => 555

            },
            {
                percentage  => 0.25,
                code        => "XXX",
                name        => "Tom Thompson",
                type        => "pt",
                location_id => 002,
                emp_cat_id  => 555

            }
        ]
    }
};

foreach my $id (keys $args->{employees}) {
    @{ $args->{employees}{$id} } = sort {
            $a->{location_id} <=> $b->{location_id}
        }
        @{ $args->{employees}{$id} }
}

dd $args;

uj5u.com熱心網友回復：

那么，您有一個 hashref，其中每個元素都是一個 hashref 的 arrayref，應該根據 hashref 內部的鍵進行排序？

#!/usr/bin/env perl
use strict;
use warnings;
use Data::Dumper;

my $hashref = {
    123 => [
        {
            percentage  => 0.25,
            code        => "XYZ",
            name        => "John Doe",
            type        => "pt",
            location_id => 001,
            emp_cat_id  => 123
        }
        ],
    555 => [
        {
            percentage  => 0.50,
            code        => "ZZZ",
            name        => "Chris Cringle",
            type        => "ft",
            location_id => 007,
            emp_cat_id  => 555
        },
        {
            percentage  => 0.25,
            code        => "XXX",
            name        => "Tom Thompson",
            type        => "pt",
            location_id => 002,
            emp_cat_id  => 555
        }
        ]
};

foreach my $arrayref (values %$hashref) {
    @$arrayref = sort { $a->{location_id} <=> $b->{location_id} } @$arrayref;
}

print Dumper($hashref);

您缺少的重要部分是取消參考陣列參考。@$arrayref而不僅僅是$arrayref.

標籤：排序 perl 哈希引用 数组引用

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