Displaying all aggregated results from Elasticsearch query in PHP - php

Question

I have a field called "arrivalDate" and this field is a string. Each document has an arrivalDate in string format (ex: 20110128). I want my output to be something like this (date and the number of records that have that date):
Date : how many records have that date
20110105 : 5 records
20120501 : 2 records
20120602 : 15 records
I already have the query to get these results.
I am trying to display aggregated results in PHP from Elasticsearch. I want my output to be something like this:
Date : how many records have that date
20110105 : 5 records
20120501 : 2 records
20120602 : 15 records
This is what I have so far:
$json = '{"aggs": { "group_by_date": { "terms": { "field": "arrivalDate" } } } }';
$params = [
'index' => 'pickups',
'type' => 'external',
'body' => $json
];
$results = $es->search($params);
However, I don't know how to display the results in PHP. For example, if I wanted to display the total number of documents I would do echo $results['hits']['total'] How could I display all the dates with the number of records they have in PHP?

Answer 1

I'd suggest using aggregations in the same way you construct the query, from my experience it seems to work quicker. Please see the below code:
'aggs' => [
'group_by_date' => [
'terms' => [
'field' => 'arrivalDate',
'size' => 500
]
]
]
Following that, instead of using the typical results['hits']['hits'] you would switch out the hits parts to results['aggregations']. Then access the returning data by accessing the buckets in the response.
For accessing the data from the aggregation shown above, it would likely be something along the lines of:
foreach ($results as $result){
foreach($result['buckets'] as $record){
echo($record['key']);
}
}
There will be a better way of accessing the array within the array, however, the above loop system works well for me. If you have any issues with accessing the data, let me know.