How do I make a Multidimension-Array of MYSQL data via PHP - php

Question

I want to create a Array with multidimension arrays from a database. The Database has 3 tables, one for vehicle, one for damages and one for damagesPhotos.
Table vehicle has two columns id and name
Table damages has four columns damagesID, vehicleID, damagesType and damagesDescription.
Table damagesPhotos has three columns damagesPhotoID and damagesID and damagesPhotoUrl
I need to combine thoose three columns into an array, that looks like this:
$vehicle = array(
"id" => "somestring",
"name" => "somestring",
"damages" => array(
"damagesType" => "somestring",
"damagesDescription" => "somestring",
"photoOfDamages" => array(
"damagesPhotoUrl" => "somestring"
)
)
);
My code looks like this, but is not working the right way.
$result = mysql_query( "SELECT * from vehicle v LEFT JOIN damages d ON v.id = d.vehicleID LEFT JOIN damagesPhotos p ON d.damagesID = p.damagesID WHERE d.damagesID = p.damagesID AND v.id = 1") or die(mysql_error());
$rowsResult = array();
while ($r = mysql_fetch_assoc($result))
{
$rowsResult [] = $r;
}
mysql_free_result($result);
echo json_encode($rowsResult);
...
/Morten

Answer 1

As its not possible in mysql, so we can write a script which gives all information about specific vehicle and with that data, we can create an array.
Refer following code.
$query = "SELECT * from vehicle v LEFT JOIN damages d ON v.id = d.vehicleID LEFT JOIN damagesPhotos p ON d.damagesID = p.damagesID WHERE d.damagesID = p.damagesID AND v.id = 1";
$result = mysql_query($query);
$i = 0;
$vehicle = array();
while($row = mysql_fetch_array($result)){
$vehicle[$i] = array(
"id" => $row[id],
"name" => $row[name],
"damages" => array(
"damagesType" => $row[damagesType],
"damagesDescription" => $row[damagesDescription],
"photoOfDamages" => array(
"damagesPhotoUrl" => $row[damagesPhotoUrl]
)
)
);
$i++;
}

Answer 2

You can't get a multidimensional array from mysql, it just gives you a two dimensional resultset. A number of column values for each row is all you can get. If you want it nested like that, you'll have to process the array after retrieving the results.
Something like this:
$vehicles = array();
while ($r = mysql_fetch_assoc($result))
{
$vehicle['id'] = $r['id'];
...
$damage = array();
$damage['damagesType'] = $r['damagesType'];
...
$vehicle['damages'] = $damage;
...
array_push($vehicles, $vehicle);
}
echo json_encode($vehicles);

Answer 3

It is not possible to have MySQL do all the work for you here (well, it is possible to have it do most of the work, but don't) because a result set from MySQL - or any SQL driven database - can have exactly two dimensions. The first dimension is a collection of rows, and the second is a collection of columns for each row.
Based on the example target data structure, you have two choices:
Get the initial result set (vehicle LEFT JOIN damages) and iterate over it, running queries to get the photos
Join all tables together as you are currently doing and post-process it into the desired multidimensional structure.
It's a trade off - option 1 results in a lot more database traffic but retrieves no more than the required data, whereas option 2 reduces it to a single query with less database traffic, but retrieves more data than required because each photo row carries the entire vehicle's data with it.
Option 1 would be a prime candidate for using prepared statements, which is something you are unable to take advantage of using the mysql_* functions. You should switch to using PDO or MySQLi instead. I personally recommend PDO. There are numerous other reasons for doing this as well, including the fact that the MySQL extension will one day be removed from PHP, and the proper use of prepared statements can completely removed any risk of security problems resulting from SQL injection via user input.
I would probably recommend option 2.

Answer 4

Thanks to Vinay, my array looks like this. Thats nice :)
[{"vehilceId":"1",
"name":"AW55005",
"damages":{
"damagesType":"Exterior",
"damagesDescription":"Rust",
"photoOfDamages":{
"damagesPhotoUrl":"link to damagesPhoto 01"
}
}
},
{"vehilceId":"1",
"name":"AW55005",
"damages":{
"damagesType":"Exterior",
"damagesDescription":"Rust",
"photoOfDamages":{
"damagesPhotoUrl":"link to damagesPhoto 02"
}
}
},
{"vehilceId":"1",
"name":"AW55005",
"damages":{
"damagesType":"Interior",
"damagesDescription":"Scratch",
"photoOfDamages":{
"damagesPhotoUrl":"link to damagesPhoto 03"
}
}
}
But as you can see the first two objects are the same only the damagesPhotoUrl is different.
How do I merge thoose two array so it will look like this:
{"vehilceId":"1",
"name":"AW55005",
"damages":{
"damagesType":"Exterior",
"damagesDescription":"Rust",
"photoOfDamages":{
{"damagesPhotoUrl":"link to damagesPhoto 01"},
{"damagesPhotoUrl":"link to damagesPhoto 02"}
}
}
}, ...
/Morten

Answer 5

After solving you main problem. I am writing this for new problem. As I know, you cant assign values to same key in your array means you cant allow to have duplicate keys. Because How would you access the value you want if more than one can have the same key. That's why you can choose another way to do merge your value. Re-arrange your array in following way.
$key = "damagesPhotoUrl";
$value = "link to damagesPhoto 01";
$array[$key][] = $value;
you can then access it as:
echo $array[$key][0];
echo $array[$key][1];

Answer 6

Its very late.... but if you using PDO then PDO::FETCH_COLUMN with PDO::FETCH_GROUP can make result in 3 dimensional array.
I think its limited, I'm not very SQL guy, but saying "You can't get a multidimensional array from mysql...or any SQL driven database - can have exactly two dimensions" can be not quite true.
Sorry for my English and off topic (this question is about mysql, not pdo)
http://php.net/manual/en/pdostatement.fetchall.php
(pseudo array):
array(
array(//group 1
array(
0=>item1,
0=>item2...
)
array(
0=>item1,
0=>item2...
)
array(
0=>item1,
0=>item2...
)
array(
0=>item1,
0=>item2...
)
)...
array(//group 2
array(
0=>item1,
0=>item2...
)
array(
0=>item1,
0=>item2...
)
)...
)