SQL groupBY with new columns creation - php

Question

I need help, just stucked here.
I have matches table.
id product_id property_id
1 1 1
2 1 2
3 1 3
4 1 4
5 2 1
6 2 2
7 2 3
8 3 1
9 3 2
10 3 3
11 3 4
12 3 5
What I need to have in result of sql query is:
product_id 1 2 3 4 5
1 1 2 3 4 null
2 1 2 3 null null
3 1 2 3 4 5
Thanks a lot in advance.
Additional. So far I tried another way, but it's too complicated. I cross joined filtered properties to obtain a result.
SELECT t1.id, t1.product_id, t1.property_id as pr_id1, t2.property_id as pr_id2
FROM
(SELECT * FROM matches WHERE (property_id = 25 OR property_id = 39)) t1
CROSS JOIN
(SELECT * FROM matches WHERE (property_id = 29)) t2
ON t1.product_id = t2.product_id

Answer 1

select
product_id,
case when sum(case when property_id = 1 then 1 else 0 end )>0 then 1 end '1',
case when sum(case when property_id = 2 then 1 else 0 end )>0 then 2 end '2',
case when sum(case when property_id = 3 then 1 else 0 end )>0 then 3 end '3',
case when sum(case when property_id = 4 then 1 else 0 end )>0 then 4 end '4',
case when sum(case when property_id = 5 then 1 else 0 end )>0 then 5 end '5'
from
t
group by product_id
http://sqlfiddle.com/#!9/ce02aa/3/0

Answer 2

Thank you all for help, it gave me couple hints.
I found alternative way to do this with crossjoins.
Basically I crossjoin as much tables as I have attributes / properties pairs.
SELECT t1.id,
t1.subproduct_id,
t1.property_id as pr_id1,
t2.property_id as pr_id2,
t3.property_id as pr_id3,
FROM
(SELECT * FROM subproduct_attributes WHERE (property_id = 25 OR property_id = 30)) t1
CROSS JOIN
(SELECT * FROM subproduct_attributes WHERE (property_id = 28)) t2
ON t1.subproduct_id = t2.subproduct_id
CROSS JOIN
(SELECT * FROM subproduct_attributes WHERE (property_id = 27)) t3
ON t1.subproduct_id = t3.subproduct_id
Here is the code of laravel implementation.
$query = $this->builder->Join('subproduct_attributes AS first', 'first.subproduct_id', '=', 'subproducts.id')
->select('subproducts.*',
DB::raw('first.subproduct_id AS sub_id'),
DB::raw('first.property_id AS prop_id'));
$previous_table = 'first';
$i = 1;
foreach ($array as $slug => $attribute) {
$keys = [];
foreach ($attribute as $property_key => $value) {
// Quick check for property existence
if (AttributeProperty::find($property_key)) {
$keys[] = $property_key;
}
}
// if it is first iteration do not crossjoin
if ($i == 1) {
$query->whereIn('first.property_id', $keys);
} else {
$query->crossJoin("subproduct_attributes AS $slug", function ($join) use ($keys, $slug, $previous_table) {
$join->on("$slug.subproduct_id", '=', "$previous_table.subproduct_id")
->whereIn("$slug.property_id", $keys);
});;
$previous_table = $slug;
}
$i++;
}