PHP - how to use array in function? - php

Question

I get an array of values returned from the following function:
function get_subscribitions($user)
{
$user = mysql_real_escape_string ($user);
$sql = "SELECT 'user_id' FROM `subscribe` WHERE subscriber = '$user'";
$result = mysql_query($sql);
$rows = array();
while ($row = mysql_fetch_assoc($result)) {
$rows[] = $row;
}
mysql_free_result($result);
return $rows;
I now want to use these values in a new function, where each "user_id" is used to collect text from the database through this function:
function get_text($writer) {
$writer = mysql_real_escape_string ($writer);
$sql = "SELECT * FROM `text` WHERE user_id='$writer' ORDER BY timestamp desc";
$result = mysql_query($sql);
$rows = array();
while ($row = mysql_fetch_assoc($result)) {
$rows[] = $row;
}
mysql_free_result($result);
return $rows;
However the returned value from the first function is an array, and as I've learnt the hard way, arrays cannot be treated by "mysql_real_escape_string".
How can I make the second function handle the values that I got from the first function?
Any responses appreciated.
Thank you in advance.

Answer 1

Your first mistake is to use mysql_fetch_assoc when only selecting one column. You should use mysql_fetch_row for this. This is likely going to fix your primary problem.
Could look like this:
$subs = get_subscribitions($whateverId);
$texts = get_text($subs);
function get_subscribitions($user)
{
$user = mysql_real_escape_string ($user);
$sql = "SELECT 'user_id' FROM `subscribe` WHERE subscriber = '$user'";
$result = mysql_query($sql);
$rows = array();
while ($row = mysql_fetch_row($result)) {
$user_id = $row['user_id'];
$rows[$user_id] = $user_id;
}
mysql_free_result($result);
return $rows;
}
function get_text($writer) {
$writers = implode(",", $writer);
$sql = "SELECT * FROM `text` WHERE user_id IN ({$writers}) ORDER BY timestamp DESC";
$result = mysql_query($sql);
$rows = array();
while ($row = mysql_fetch_array($result)) {
$rows[] = $row;
}
mysql_free_result($result);
return $rows;
}
This will save you a lot of time, because you can get all data from 'text' in one statement.

Answer 2

The solution is to avoid placing arrays in your $rows array in the first function. Instead of:
while ($row = mysql_fetch_assoc($result)) {
$rows[] = $row;
}
try:
while ($row = mysql_fetch_assoc($result)) {
$rows[] = $row['user_id'];
}
This will place only the value from column 'user_id' in the $rows array.

Answer 3

In order to use the second function you must iterate over the array returned from the first one. Something like this could work for you:
$user_subscriptions = get_subscribitions($user);
foreach($user_subscriptions as $subscription) {
$texts = get_text($subscription['user_id']);
foreach($texts as $text) {
// do something with the fetched text
}
}

Answer 4

As George Cummins says,
while ($row = mysql_fetch_assoc($result)) {
$rows[] = $row['user_id'];
}
and, to speed up the second function:
function get_text($writer)
{
$sql = "SELECT * FROM `text` WHERE user_id in (".implode(',',$writer).") ORDER BY timestamp desc";
$rows = array();
if ($result = mysql_query($sql))
{
while ($row = mysql_fetch_assoc($result))
{
$rows[] = $row;
}
mysql_free_result($result);
}
return $rows;
}
The change to the query means that you only do one in total rather than one for each ID thus removing the time taken to send the query to the server and get a response multiple times. Also, if the query fails, the function returns an empty array

Answer 5

Use :
string implode ( string $glue , array $pieces )
// example, elements separated by a comma :
$arrayasstring = impode(",", $myarray);

Answer 6

function get_subscribitions($user)
{
$user = mysql_real_escape_string ($user);
$sql = "SELECT 'user_id' FROM `subscribe` WHERE subscriber = '$user'";
$result = mysql_query($sql);
$row = mysql_fetch_row($results);
mysql_free_result($result);
return intval($row['user_id']);
}
it return only the user id you can used it in the 2nd function