How to fetch PHP database values in Json? - php

Question

I have to create Matrix tree view in my project. So am plan to use json. My question is how to fetch PHP values in Json ?. I did static matrix tree but i want dynamic. Thank you for advance.
My code is following:
<?php
include('db.php');
$select = mysql_query("select * from table1");
while($row = mysql_fetch_array($select))
{
?>
{
"name": "A", // Here database values come $row['name'];
"children": [
{
"name": "B",
"children": [
{"name": "B-1"}
]
},
{
"name": "C",
"children": [
{"name": "C-1", "size": 1082},
{"name": "C-2", "size": 1681}
]
},
{
"name": "D",
"children": [
{
"name": "D-1",
"children": [
{"name": "D-1 1", "size": 1302},
{"name": "D-1 2", "size": 6703}
]
},
{"name": "D-2", "size": 16540}
]
}
]
}
<?php
}
?>

Answer 1

In this example Im using the mysqli driver. Do not use the mysql driver.
you just need to convert your output data into a json object.
Its possible to extract all the rows at once which is going to give you a marginally less overhead.
$data = mysqli_fetch_all($select); // returns everything in an associative array
$json_data = json_encode($data); // converts that array to json.
if you need specific keys, then manipulate your query to rename columns as necessary eg.
$query = "select name as firstname from ....";

Answer 2

You can just retrieve data from your database and store it in arrays like you normally would. Then call PHP's built in function json_encode() to transform your PHP array into json (assuming your PHP array is well formed (which should be the case if you get it out of a database)).
You could argue that this is slower because you're iterating over the data twice instead of once, but it shouldn't matter, the complexity remains the same.