Create a Multidimensional Array with PHP and MySQL - php

Question

I am new to PHP and am looking at efficient ways to return data from the database. Lets say I have a UserProfile table that has a one to many relationship with UserInterest and UserContact:
Select p.Id, p.FirstName, p.LastName, i.Name as Interests, c.Email, c.Phone
from UserProfile p
left join UserInterest i on p.Id = i.UserProfileId
left join UserContact c on p.Id = c.UserProfileId
where p.Id = 1
An efficient way to retrieve data would be to create a multidimensional array such as:
$user = array( "FirstName" => "John",
"LastName" => "Doe",
"Gender" => "Male",
"Interests" => array(
"Hiking",
"Cooking"),
"Contact" => array(
"Email" => "john.doe#gmail.com",
"Phone" => "[phone]"));
I can't seem to get my head around how this would be constructed in PHP. For simple data like interests I could use group_concat(i.Name) as Interests in the query to return interests back as a comma separated list in a single row, however, for an associative array such as Contact, I'd like to be able to get a handle on each key in the array using $user['Contact']['Email'].
From a "Best Practices" standpoint, I would assume that constructing an array like this in one query is a lot better than hitting the database multiple times to retrieve this data.
Thanks!
Neil

Answer 1

You can construct this array in one pass through the data returned by your query. In pseudo-code:
for each row
$user["FirstName"] = row->FirstName;
$user["LastName"] = row->LastName;
$user["Interests"][] = row->Interests;
$user["Contact"]["Email"] = row->Email;
$user["Contact"]["Phone"] = row->Phone;
next
The syntax $user["Interests"][] = $data is valid PHP code. It is equivalent to array_push($user["Interests"], $data).

Answer 2

My guess is that you would have to run separate queries and manually construct the array yourself. I don't personally know of any MySQL database resources in PHP that return rowsets like that in a multidimensional array the way you described.

Answer 3

A better way of doing this could be:
$query = "SELECT p.Id, p.FirstName, p.LastName, i.Name as Interests,
c.Email, c.Phone
FROM UserProfile p
LEFT JOIN UserInterest i ON p.Id = i.UserProfileId
LEFT JOIN UserContact c ON p.Id = c.UserProfileId
WHERE p.Id = 1";
$res = GIDb::pg_query($query);
if(pg_num_rows($res) > 0)
{
while($data = pg_fetch_assoc($res))
{
$id = $data['Id'];
$f_name = $data['FirstName'];
$l_name = $data['LastName'];
$interests = $data['Interests'];
$email = $data['Email'];
$phone = $data['Phone'];
}
}
//You can also directly use $data['Id'] etc.
Also don't forget to include in the beginning of the php code : include_once(dirname(__FILE__)."/../../class.GIDb.php");
EDIT :
This is for Postgres.
For MySQL use: mysql_query(), mysql_fetch_assoc(), mysql_num_rows()