Add new elements to the result from MySQL query via php - php

Question

I have the following question, let's say I'm querying MySQL database to get the following array:
Array ( [0] => Array ( [topicid] => 4 ) [1] => Array ( [topicid] => 5 ) [2] => Array ( [topicid] => 6 ) )
These are the results from that I get from the following SQL request
$sql=$db->query("SELECT topicid from opentopics WHERE userid=?","$userid")->fetchAll();
This query gives me the list of topics that are opened to certain user ids. Now there are several topics with IDs up to 3 that are open to everyone, so I want to use them also on my webpage. These topics are not opened in the opentopics table, but are made available to everyone based on their ID (less than 3).
So the question is following, how do I modify the multidimensional (i assume) array I get from MySQL request, how to add 3 new entries to the beghinning of the above mentioned array so it looks like:
Array ( [0] => Array ( [topicid] => 1 ) [1] => Array ( [topicid] => 2 ) [2] => Array ( [topicid] => 3 ) [3] => Array ( [topicid] => 4 ) [4] => Array ( [topicid] => 5 ) [5] => Array ( [topicid] => 6 ) )
As you may have notices in my text editory I have manually edited the text of the array, by adding this
[0] => Array ( [topicid] => 1 ) [1] => Array ( [topicid] => 2 ) [2] => Array ( [topicid] => 3 )

Answer 1

you can fetch your result like this example then use array_merge
$mysqli = new mysqli('localhost', 'root', '', 'test');
$manual = array(
[ 'id' => 9 , 'first_name' => 'John9' , 'last_name' => 'Doe9'] ,
[ 'id' => 19 , 'first_name' => 'John19' , 'last_name' => 'Doe19']
);
$sql = " SELECT * from users ";
$result = $mysqli -> query($sql);
$rows = $result -> fetch_all(MYSQLI_ASSOC);
$results = array_merge($manual , $rows);
the results will be like this
Array
(
[id] => 9
[first_name] => John9
[last_name] => Doe9
)
Array
(
[id] => 19
[first_name] => John19
[last_name] => Doe19
)
Array
(
[id] => 1
[first_name] => John
[last_name] => Doe
)
Array
(
[id] => 2
[first_name] => John3
[last_name] => Doe
)
Array
(
[id] => 4
[first_name] => John4
[last_name] => Doe
)