Laravel 6 query same table with different where clause - php

Question

I have campaign_report table like this
Schema::create('campaign_report', function (Blueprint $table) {
$table->bigIncrements('id');
$table->date('report_date');
$table->bigInteger('user_id');
$table->bigInteger('campaignId');
$table->double('cost',12,2);
$table->timestamps();
});
I am trying to get all yesterday's campaign reports.
$campaignReports = CampaignReport::where(['report_date' => "$yesterday", 'user_id' => Auth::user()->id])->orderBy('report_date', 'desc')->paginate(25);
Above query is returning all campaigns where report_date is equal to $yesterday.
Along with this query I also want to get the cost value of each campaign where report_date is day before yesterday matching the campaignId column. I want to show the difference of cost between yesterday's campaigns and day before yesterday's campaigns.
like
foreach($campaignReports as $campaignReport)
{
$difference = $campaignReport->cost - $campaignReport->dayBeforeYesterdayCost;
}
Can anyone help me in building this query using Query Builder or Eloquent?

Answer 1

You can write a relation in your CampaignReport model that calculate difference between yesterday's cost and the day before that
public function dayBeforeYesterdayCost() {
$dayBeforeYesterday = Carbon::parse($this->report_date)->subDays(1); //return date of day before yesterday
$dayBeforeYesterdayCost = CampaignReport::where('campaignId', $this->campaignId)
->where('report_date', $dayBeforeYesterday)
->first();
return $dayBeforeYesterdayCost ? $dayBeforeYesterdayCost->cost : 0;
}
public function lastDayDifference() {
$difference = $this->cost - $this->dayBeforeYesterdayCost;
return $difference;
}
Now you can return $campaignReports with lastDayDifference relation like this:
$campaignReports = CampaignReport::where(['report_date' => "$yesterday", 'user_id' => Auth::user()->id])
->with('lastDayDifference')
->orderBy('report_date', 'desc')
->paginate(25);
At the end you have one object attached to your every single $campaignReport

Answer 2

Group by date(report_date) which will just give you the date part, order by the same descending, then just take the values for yesterday and the day before. Something like:
CampaignReport::select(DB::raw('date(report_date) report_date', DB::raw('count(*) as count'))
->where('report_date','>=',$twoDaysAgo)
->where('user_id', Auth::user()->id])
->groupBy('report_date')
->orderBy('report_date', 'desc');