Very Complex SQL Data Result Merge via PHP (Multi Dimentional Arrays) - php

Question

Sorry, I have a hard time to write proper thread title for this problem.
Here's my question:
In short: How to merge array item and calculate.
Here's the full explanation
1) I have a (WP custom) database to track statistics: visits, unique visits, etc, and it's stored per post per date.
To make it easier to understand. Here's the screenshot of the table:
2) This is the example data when I queried it:
https://gist.github.com/turtlepod/8e7dc93bae7f0b665fd5aea8a9694998
So in this example we have multiple post ID: "90", "121", & "231"
We have multiple date in db: "2017-03-20", "2017-03-21", "2017-03-22"
We have multiple stats: "visits", and "unique_visits"
We also have a "stat_value" for each item.
Each item have unique ID.
All data is dynamically created when an event happen. so not all post_id have 2 stats or the above date.
Note: keep in mind that in real code, we have a lot more data and variations than the example above.
3) I need to merge the data:
The post_id "121" is the same as post "231", so we need to merge and add the "stat_value" into one data and remove "231" entry.
What is the best way to do this (dynamically) via PHP ?
I have this data:
$raw_data = array( ... ); // the one in github gist
$post_groups = array(
'121' => array( '121', '231' ), // main post_id => array of alias.
);
It need to return the same data format as $raw_data, but remove the data of "231" and include/sum the "stat_value" of "231" to "121".
Thank you.

Answer 1

Try it with this:
function david_transform_data($data, $groups) {
if (empty($groups) === true) {
return $data;
}
// Transform groups into a more useful format
$transformed_groups = array();
foreach ($groups as $post_id => $aliases) {
foreach ($aliases as $alias) {
if (absint($post_id) === absint($alias)) {
continue;
}
$transformed_groups[absint($alias)] = $post_id;
}
}
// Replace aliases with the real post id
foreach ($data as $index => $stat) {
if (isset($transformed_groups[absint($stat->post_id)]) === false) {
continue;
}
$data[$index]->post_id = $transformed_groups[absint($stat->post_id)];
}
// Go through stats and merge those with the same post_id, stat_id
// and stat_date
$merged_stats = array();
$index_tracker = 0;
$stats_hash = array();
foreach ($data as $index => $stat) {
$hash_key = sprintf(
'%s-%s-%s',
$stat->post_id,
$stat->stat_id,
$stat->stat_date
);
if (isset($stats_hash[$hash_key]) === true) {
$merged_stats[$stats_hash[$hash_key]]->stat_value += absint($stat->stat_value);
continue;
}
$merged_stats[] = $stat;
$stats_hash[$hash_key] = $index_tracker;
$index_tracker++;
}
return $merged_stats;
}
var_dump(david_transform_data($raw_data, $post_groups));
There might be a faster solution but this is the first thing that came to my mind.