How to manipulate and collate data in an associate array - php

Question

I have the following array of data
2889 1 1062
2889 8 John Smith
2889 6 0.29
2891 1 1117
2891 8 Jamie Dean
2891 6 2
2892 1 1062
2892 8 John Smith
2892 6 4
The First column is a list of entry IDs relating to form entries from a website, the second column is a list of meta_keys relating to fields in the form, and the final column is the data from those fields.
What I need to be able to do is collate the data in the array so that for each person I have:
ID Number(Meta_key 1)
Name(Meta_key 8)
Sum(Hours Owed(Meta_key 6))
I am lost on how to even start this task, any help would be very much appreciated.
This data has all been pulled from a database with the following query:
select
entry_id,
meta_key,
meta_value
from
staff_gf_entry_meta
where
form_id = 48
and
entry_id in (
select
entry_id
from
staff_gf_entry_meta
where
meta_key = 7
and
form_id = 48
and
meta_value <= '2018-12-18'
and
meta_value >= '2018-12-12'
)
and (
meta_key = 1
or
meta_key = 8
or
meta_key = 6)
If needed the query can be altered.

Answer 1

You might want a GROUP BY statement with the SUM aggregate function. To get all the key/value pairs in a row, you need to JOIN multiple queries.
SELECT
`mk1`.`meta_value` `Number`,
`mk8`.`meta_value` `Name`,
SUM(`mk6`.`meta_value`) `Hours Owed`
FROM
`staff_gf_entry_meta` `mk1`
INNER JOIN
`staff_gf_entry_meta` `mk6`
USING
(`entry_id`, `form_id`)
INNER JOIN
`staff_gf_entry_meta` `mk7`
USING
(`entry_id`, `form_id`)
INNER JOIN
`staff_gf_entry_meta` `mk8`
USING
(`entry_id`, `form_id`)
WHERE
`mk1`.`meta_key` = 1
AND
`mk6`.`meta_key` = 6
AND
`mk7`.`meta_key` = 7
AND
`mk8`.`meta_key` = 8
AND
`mk1`.`form_id` = 48
AND
`mk7`.`meta_value` BETWEEN '2018-12-12' AND '2018-12-18'
GROUP BY `mk1`.`meta_value`,`mk1`.`form_id`
;
I've assumed the following table structure and data:
CREATE TABLE `staff_gf_entry_meta`
(
`form_id` int(11) NOT NULL,
`entry_id` int(11) NOT NULL,
`meta_key` int(11) NOT NULL,
`meta_value` varchar(45) DEFAULT NULL,
PRIMARY KEY (`entry_id`,`form_id`,`meta_key`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4
;
INSERT INTO `staff_gf_entry_meta` (form_id, entry_id, meta_key, meta_value)
VALUES
(48, 2889, 1, 1062),
(48, 2889, 8, 'John Smith'),
(48, 2889, 6, 0.29),
(48, 2891, 1, 1117),
(48, 2891, 8, 'Jamie Dean'),
(48, 2891, 6, 2),
(48, 2892, 1, 1062),
(48, 2892, 8, 'John Smith'),
(48, 2892, 6, 4)
;
INSERT INTO `staff_gf_entry_meta`
SELECT DISTINCT form_id, entry_id, 7 meta_key, '2018-12-17' meta_value
FROM testdb.staff_gf_entry_meta
;
Result:
# Number, Name, Hours Owed
'1062', 'John Smith', '4.29'
'1117', 'Jamie Dean', '2'

Answer 2

Start with something like below, and build from there.
$meta_labels = [
1 => 'ID'
8 => 'name'
6 => 'hours'
];
$output = [];
foreach($results as result) {
$eid = $result['entry_id'];
$label = $meta_labels[$result['meta_key']];
$output[$eid][$label] = $result['meta_value'];
}
And ideally the mapping between metadata IDs and their labels should be stored in the database, not hard-coded in the application.