How to get last items first by using foreach - php

I use foreach to show items from mysql table, but it lists first items first.
I want to list last items first.
The code:
foreach ( $result as $print ) {
$print->sender_user;
$print->reciever_user;
$print->content;
}
I mean that if I add a new item to mysql table this code should show
it above the other items. But it shows first added item last.

Simple, use array_reverse
http://php.net/manual/en/function.array-reverse.php
array_reverse — Return an array with elements in reverse order
$result = array_reverse($result);
foreach ( $result as $print ) {
$print->sender_user;
$print->reciever_user;
$print->content;
}
Otherwise if it's numerically indexed you can always use for
$len = count($result)-1;
for($i=$len; $i>=0; --$i){
$row = $result[$i];
}
And my favorite
$result = [1,2,3,4];
$row = end($result);
do{
echo $row."\n";
}while($row = prev($result));
Try it here
https://3v4l.org/NINss
And with just while, you cant do prev in the while condition because you lose the last element of the array, so it's a bit lamer.
$result = [1,2,3,4];
$row = end($result);
while($row = current($result)){
echo $row."\n";
prev($result);
}
https://3v4l.org/No1Rb
I think that is about it, I could probably do one with goto but that would be showing off.

Related

When I try to access to array items I only get the 1. one

Here's my Query
$rows = $mydb->get_results("SELECT title, description
FROM site_info
WHERE site_id='$id';");
I get something like:
Title1 Desc1
Title2 Desc2
etc.
I want to put that data in array so I do:
$data = array();
foreach ($rows as $obj) {
$data['title'] = $obj->title;
$data['description'] = $obj->description;
}
When I do:
print_r($data);
I only get title and description of first item... Please help :/ I checked and my query returns all what i want to be in array not only the first row.
You are over-writing array indexes each time in iteration.You need to create new indexes each time when you are assigning the values to array.
So either do:-
$data = array();
foreach ($rows as $key=>$obj) { // either use coming rows index
$data[$key]['title'] = $obj->title;
$data[$key]['description'] = $obj->description;
}
Or
$data = array();
$i=0; //create your own counter for indexing
foreach ($rows as $key=>$obj) {
$data[$i]['title'] = $obj->title;
$data[$i]['description'] = $obj->description;
$i++;// increase the counter each time after assignment to create new index
}
For display again use foreach()
foreach ($data as $dat) {
echo $dat['title'];
echo $dat['description'];
}
If the eventual goal is simply to display these values, then you shouldn't bother with re-storing the data as a new multi-dimensional array.
$rows = $mydb->get_results("SELECT title, description FROM site_info WHERE site_id='$id';");
If $id is user-supplied data or from an otherwise untrusted source, you should implement some form of sanitizing/checking as a matter of security. At a minimum, if the $id is expected to be an integer, cast it as an integer (an integer doesn't need to be quote-wrapped).
$rows = $mydb->get_results("SELECT title, description FROM site_info WHERE site_id = " . (int)$id);
When you want to display the object-type data, just loop through $rows and using -> syntax to echo the values.
echo "<ul>";
foreach ($rows as $obj) {
echo '<li>' , $obj->title , ' & ' , $obj->description , '</li>';
}
}
echo "</ul>";
If you have a compelling reason to keep a redundant / restructured copy of the resultset, then you can more simply command php to generate indexes for you.
foreach ($rows as $obj) {
$data[] = ['title' => $obj->title, 'id' => $obj->id];
}
The [] is just like calling array_push(). PHP will automatically assign numeric keys while pushing the associative array as a new subarray of $data.

adding items to array during foreach on the array

I wish to run a foreach on a load of ID's.
However each of the items in the foreach is a select query and if it finds more ID's they need to be added to the array that is being run in the foreach.
E.g
$ids = array();
foreach($ids as $id)
{
SELECT id FROM table WHERE otherid = $id;
foreach ($query2->result_array() as $row)
{
array_push($array, $row['id']);
}
}
This is obviously pseudocode so no need to correct my SQL etc. I just need for the foreach to continue if it finds more ID's.
Possible?
I have tried adding an & here -> foreach($ids as &$id) as somebody else on here has suggested in a similar question. This doesn't seem to work.
foreach actually makes a copy of your array to loop though, you will need to use while.
while(list($id_key, $id) = each($ids)){
//your code
$ids[] = $row[id];
}
You should simply be able to just reference the original array ie
foreach ($query2->result_array() as $row)
{
$id[] = $row;
}
This will automatically assign an auto incremented key to the the new array element and add it to the $id array. I assume this is what you are after.
Try to iterate with a variable:
$ids = array();
$i = 0;
while ($i < count($ids)) {
$query2->query(SELECT id FROM table WHERE otherid = $ids[$i]);
foreach ($query2->result_array() as $row)
$ids []= $row['id'];
$i++;
}
For similar problems, I have always used two different arrays. Such code can run a query for every id only one time. I don't think it would be possible with only one array+foreach;
The following code is pretty simple. It keeps finding new ids until there are no new ids.
$ids = array();
$new = array();
$new = $ids;
do {
foreach($new as $n) {
$new = array();
//// HERE PUT YOUR CODE TO RUN A QUERY AND MAYBE PUSH A NEW ID TO $new \\\\
}
$ids = array_merge($ids,$new);
} while (count($new)!==0);

PHP Nested Loop. How on the second loop print items according to the id of the first loop?

I need to print a wine list from a database.
I need to print at first a categorie and after all the items that are inside. Thats the order. And i have multiple categorie. So at the end the result will be categorie1, many items, categorie2 many items...
This is the code that i write from now: I think that my problem is to print items according to the id of the alcool_categorie !!
$q_vine = "SELECT * FROM alcool_categorie ";
$r_vine = mysql_query($q_vine,$connection);
$n_vine = mysql_num_rows($r_vine);
$q_bouteille = "SELECT * FROM alcool_item where ALCNID = '$alid'";
$r_bouteille = mysql_query($q_bouteille,$connection);
$n_bouteille = mysql_num_rows($r_bouteille);
for($i = 0; $i < $n_vine; $i++){
echo mysql_result($r_vine,$i,'named').'<br/><br/>';
for($z = 0; $k < $n_bouteille; $k++){
echo mysql_result($r_bouteille,$k,'name').'<br/>';
}
}
I think it's best to use a "JOIN" in your query and then order the rows in the way you want them to be ordered, then you'll only need one loop. While running the loop you compare the category name with the previous category name and if it changes display the category name.
Example
$sql = "SELECT categoryName, bottleName FROM category INNER JOIN bottle ON category.categoryId = bottle.categoryId ORDER BY category.categoryId";
$result = mysql_query($sql,$connection);
$categoryName = ''; //just to make sure the first time the Category is named
while ($row = mysql_fetch_assoc($result)) {
if($categoryName != row['categoryName']){
$categoryName = row['categoryName'];
echo '<h1>'.$categoryName.'</h1>';
}
echo row['bottleName'].'<br/>';
}
Try this after correctly giving the category id field name in the query and inside the first while loop.
$q_vine = "SELECT id, named FROM alcool_categorie ";
$r_vine = mysql_query($q_vine,$connection);
$n_vine = mysql_num_rows($r_vine);
while ($row = mysql_fetch_assoc($r_vine)) {
$categories[$row['id']] = $row;
}
$q_bouteille = "SELECT name, ALCNID FROM alcool_item ";
$r_bouteille = mysql_query($q_bouteille,$connection);
$n_bouteille = mysql_num_rows($r_bouteille);
while ($row = mysql_fetch_assoc($r_bouteille)) {
$items[$row['ALCNID']] = $row;
}
foreach ($categories as $category_id=>$category) {
echo "<ul><li>{$category['named']}<ul>";
foreach ($items[$category_id] as $item) {
echo "<li>{$item['name']}</li>";
}
echo "</ul></li></ul>";
}
You will want to look into PHP's foreach construct. Foreach loops through an entire array of results, for each element inside the array, it extracts its value and optionally also its key. This will not require the use of mysql_num_rows.
Instead of calling mysql_result, you could use mysql_fetch_assoc to get a row's value from your mysql_query. The row's To get all values, you can incorporate this into a loop even. If you do the latter, you can create your own array of key/value pairs and use this inside a foreach construct.
Also note that the use of mysql is outdated, you will want to use mysqli now, which is very similar to mysql.

PHP For Loop Printing An Array

This might seem like a really easy question but it has got me stumped lol. I am trying to print the rows received from the database. I want to store the rows inside an array and then print them using a for loop. I know that the query works however when I try to print the array elements it only prints the word array. I have tired doing it with a foreach loop and a simple for loop. If anyone can point me in the right direction would be a life saver.
Printing Php Code
<?php
$type = "FREE";
$free = getTerms($type);
echo "<p>";
for($j = 0; $j < count($free); $j++)
{
echo "start".$free[$j]."end";
}
echo "</p>";
?>
geting the rows from the database
function getTerms($type)
{
$terms = array();
$connection = mysql_open();
$query = "select terms from terms_and_con where accountType='$type' && currentTerms='YES'";
$results = mysql_query($query, $connection) or show_error("signUp.php", "", "");
while($row = mysql_fetch_array($results))
{
$terms[] = $row;
}
mysql_close($connection) or show_error("signUp.php", "", "");
return $terms;
}
Each entry in the $free array is itself an array (from $row).
Try
echo 'start', $free[$j]['terms'], 'end';
Alternatively, you may find a foreach loop more semantically appropriate
foreach ($free as $row) {
echo 'start', $row['terms'], 'end';
}
Edit: I'd advise using mysql_fetch_assoc() instead of mysql_fetch_array() if you're only going to use associative entries from $row.
the thing is function mysql_fetch_array ( as the name suggests) returns an ( in your case both associative and number) array. so $row is actually array(0 => VALUE, 'terms' => 'VALUE')
So what you are trying to echo is actually an array.
Simple fix:
replace:
$terms[] = $row;
with:
$terms[] = $row[0];

How do you save rows to an array and print out in PHP using ODBC?

I have the following:
while($myRow = odbc_fetch_array( $result )){ <--lots of rows
$thisResult['name'] = $myRow["name"] ;
$thisResult['race'] = $myRow["race"] ;
$thisResult['sex'] = $myRow["sex"];
$thisResult['dob'] = $myRow["dob"];
}
I can't figure out how to print this back out.
I want to get each row and iterate through each row in the array like a datareader. I'm not sure what to do. I do not want to do the echo in the while. I need to be able to print it out elsewhere. But I don't think I've done it right here to be able to print it later.
I also tried, this, however:
while($myRow = odbc_fetch_array( $result )){ <--lots of rows
print($thisResult[$myRow["name"]] = $myRow);
}
I then tried:
while($myRow = odbc_fetch_array( $result )){ <--lots of rows
print (odbc_result($myRow,"name"));
}
but got an error.
Thank you for any help.
EDIT: when I do this:
while($myRow = odbc_fetch_array( $result )){
print ($myRow["name"]);
}
I get undefined index name. I am mainly concerned with saving to an array but I have to be able to do it in the loop first.
Declare an array before and assign the values to it:
$rows = array();
while($myRow = odbc_fetch_array( $result )){ <--lots of rows
$rows[] = $myRow;
}
Then you can print it e.g. this way:
foreach($rows as $row) {
foreach($row as $key => $value) {
echo $key . ': '. $value;
}
}
or however you want to.
You don't have to access and assign $thisResult['name'] = $myRow["name"] in your while loop as $myRow already is an array. You just copy the values which is unnecessary.
You say you have a lot of rows. Depending of what you really want to do with data, it might be better to put all this functionality into the while loop to avoid creating an array.
How about something like:
$output = '';
while($myRow = odbc_fetch_array( $result )) {
$output = $output."Your name is {$myRow["name"]} and your race is {$myRow["race"]}\n";
}
// print output later...

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