How to perform GroupBy of a GroupBy in laravel? - mysql

Question

I have a reports table which looks like something as follows:
Reports is monthly reports of users putting their efforts. It's many to many relationship table.
id
user_id
project_id
total_effort
created_at
1
5
232
40
2023-01-23
I want to get all users with their contributions projects-wise so that I can create an excel something like this.
I am able to group users by group and get their collective data, but unable to group by project id as well.
So far here is my query
$data = Report::select('user_id')
->selectRaw("SUM(total_effort) as total, DATE_FORMAT(report_for_date, '%b,%Y') new_date")
->groupBy('user_id')->with('userDetail:id,first_name,last_name')->get();
And this query return
[0] => Array
(
[user_id] => 2
[total] => 500
[new_date] => Dec,2022
[user_detail] => Array
(
[id] => 2
[first_name] => Hermione
[last_name] => Granger
)
)
But what I am actually looking for is something like this:
[0] => Array
(
[user_id] => 2
[total] => 500
[new_date] => Dec,2022
[projects]=>Array(
[0]=>Array(
[project_id]=>1,
[total]=>30,
[project_detail]=>Array(
[id]=>1
[name]=>Project 1
)
)
[1]=>Array(
[project_id]=>41,
[total]=>30,
[project_detail]=>Array(
[id]=>41
[name]=>Project 41
)
)
[2]=>Array(
[project_id]=>32,
[total]=>30,
[project_detail]=>Array(
[id]=>32
[name]=>Project 32
)
)
)
[user_detail] => Array
(
[id] => 2
[first_name] => Hermione
[last_name] => Granger
)
)
So that I can loop the data and plot them in excel.
How can this be done? Even if it is just a Raw MySQL query how to do Groupby inside a groupBy?
Some reference that I checked but without any help
sql group by sub group
Mysql Nested query and GROUP BY
using group function inside group function

Answer 1

You can use with() method to load the relation with groupby clause
$data = Report::select('user_id', 'project_id')
->selectRaw("SUM(total_effort) as total, DATE_FORMAT(report_for_date, '%b,%Y') new_date")
->groupBy('user_id')
->groupBy('project_id')
->with('userDetail:id,first_name,last_name')
->with('projectDetail:id,name')
->get();

Answer 2

I would query the active projects within the reporting period and then use that to build up the main query with conditional aggregation (pivot) -
// get list of projects within reporting period
$projects = DB::table('projects p')
->join('reports r', 'p.id', '=', 'r.project_id')
->select('p.id', 'p.name')
->whereBetween('r.created_at', ['2023-01-01', '2023-01-31'])
->groupBy('p.id')
->get();
// build conditional aggregates
$columns = ['CONCAT(u.first_name, \' \', u.last_name) AS username'];
foreach ($projects as $project) {
$columns[] = "SUM(IF(r.project_id = {$project->id}, total_effort, 0)) AS project_{$project->id}";
}
// Add total column
$columns[] = 'SUM(total_effort) AS total';
$report = DB::table('reports r')
->join('users u', 'r.user_id', '=', 'u.id')
->selectRaw(implode(',', $columns))
->whereBetween('r.created_at', ['2023-01-01', '2023-01-31'])
->groupBy('r.user_id')
->get();
The idea is to build and execute a query which looks something like this -
SELECT
CONCAT(u.first_name, ' ', u.last_name) AS username,
SUM(IF(r.project_id = 232, total_effort, 0)) AS project_232,
SUM(IF(r.project_id = 233, total_effort, 0)) AS project_233,
SUM(IF(r.project_id = 234, total_effort, 0)) AS project_234,
SUM(total_effort) AS total
FROM reports r
JOIN users u ON r.user_id = u.id
WHERE r.created_at BETWEEN '2023-01-01' AND '2023-01-31'
GROUP BY r.user_id