DBIx::Class : Resultset order_by based upon existence of a value in the list - sql

Question

I am using DBIx::Class and I have got a ResultSet. I like to re-order the ResultSet. I like to check a particular column "City" against a fix list of values ("London", "New York" "Tokyo") If city is found in the list of values I like to move that result to the top group. If city is not found, I like to move that result to the bottom group in the ResultSet.

Answer 1

ORDER BY expr might be what you're looking for.
For example, here a table:
mysql> select * from test;
+----+-----------+
| id | name |
+----+-----------+
| 1 | London |
| 2 | Paris |
| 3 | Tokio |
| 4 | Rome |
| 5 | Amsterdam |
+----+-----------+
Here the special ordering:
mysql> select * from test order by name = 'London' desc,
name = 'Paris' desc,
name = 'Amsterdam' desc;
+----+-----------+
| id | name |
+----+-----------+
| 1 | London |
| 2 | Paris |
| 5 | Amsterdam |
| 3 | Tokio |
| 4 | Rome |
+----+-----------+
Translating this into a ResultSet method:
$schema->resultset('Test')->search(
{},
{order_by => {-desc => q[name in ('London', 'New York', 'Tokyo')] }}
);

Answer 2

Something like:
#!/usr/bin/env perl
use strict;
use warnings;
my $what = shift or die;
my #ary = qw(alpha beta gamma);
unshift(#ary,$what) unless ( grep(/$what/,#ary) );
print "#ary\n";
1;
Run as:
./myscript omega