SQL query JSON of MySQL 8.0 comes String instead of Array - php

Question

I create a table in MySQL 8.0 as follows:
CREATE TABLE `airline_table` (
`id` int unsigned NOT NULL AUTO_INCREMENT,
`info` json DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;
It contains JSON type data, and I insert some data as:
INSERT INTO airline_table VALUES ('1','{"data": [{"city": "Houston", "state": "TX"},
{"city": "Los Angles", "state": "CA"}], "airline": ["UA", "AA"]}');
And I use php to visit the database, I wish to get value of "airline" as an Array.
<?php
$mysqli = new mysqli("localhost", "root", "aproot2019", "test");
$sql = "SELECT id, info -> '$.airline' AS airline FROM airline_table";
$result = $mysqli->query($sql);
$row = $result->fetch_array();
//print_r($row);
$airline = $row['airline'];
echo $airline . "<br>"; // ["UA", "AA"] , this is a string but not an array, how can I have an Array?
echo is_array($airline) ? 'Array' : 'not an Array' . "<br>"; // not an Array
echo is_string($airline) ? 'String' : 'not a String' . "<br>" ; // String
$mysqli->close();
?>
But it comes out a String, NOT an Array!
This really annoys me, and JSON in MySQL is hard to understand.

Answer 1

Have you considered decoding JSON?
$json = json_decode('{"data": [{"city": "Houston", "state": "TX"}, {"city": "Los Angles", "state": "CA"}], "airline": ["UA", "AA"]}');
// for your case it will be :
// $json = json_decode($row['airline']);
echo var_dump($json->airline);
/**
* array(2) {
[0]=>
string(2) "UA"
[1]=>
string(2) "AA"
}

Answer 2

Querying a JSON from MySQL is not hard, but.... For this kind of tables I would not do it in JSON. 😉
SELECT
j.city,
j.state
FROM airline_table
CROSS JOIN JSON_TABLE(info, '$.data[*]' COLUMNS(
city VARCHAR(20) PATH '$.city',
state VARCHAR(20) PATH '$.state')) as j
output:
city
state
Houston
TX
Los Angles
CA