I export from MYSQL db different info that I put inside an array:
$info=array(
(ID,CALORIES,PROTEIN,CARBOS,FIBER),
...
);
ex: (1,270,24,12,5),(2,280,2,42,10),...
Then, further down the script, I need to get the IDs of the 3 products with the highest calories, of the 6 products with the highest result of 2xPROTEIN+3xCARBOS, etc for 5 charts.
How can I do such a sorting of the array to fill my different tables?
The function sort() only seems to work for a single-dimensioned array (if it works for my case, I don't know what would be the syntax). It also doesn't seem to work for my more advanced sortings (2*x+3*y)...
Even tho it is not exactly what you are asking, I would highly suggest you preparing your tables in mysql (using all formulas to sort, etc.). Mysql's main job is do various selections and sorting, I would leave the work for it. Moreover, advanced sorting in mysql is way easier than thinking of algorithms or functions in php :)
SELECT * FROM `products`
ORDER BY (2*PROTEIN+3*CARBOS) DESC
Easy as that and no headaches. Apply LIMIT 3 at the end to get the top 3. Update
SELECT * FROM `products`
to your more advanced query. If having difficulties in code you may try to wrap it up as a subquery as this:
SELECT * FROM (SELECT * FROM `products` WHERE `type`='fruit' LIMIT 6) a
ORDER BY (2*PROTEIN+3*CARBOS) DESC LIMIT 3
You can use array_multisort() to sort multidimensional arrays. The syntax allows for quite some flexibilty, see the reference.
You can use usort function:
function cmp( $a, $b )
{
if( $a["calories"] *3+ $a["protein"]*2 == $b["calories"] *3+ $b["protein"]*2){ //do another comparison etc.. ; }
return ($a["calories"] *3+ $a["protein"]*2< $b["calories"] *3+ $b["protein"]*2)) ? -1 : 1;
}
usort($myarray,'cmp');
usort is your friend here.
function sort2Protein3Carbo($a, $b)
{
// Assuming protein is the 2nd value in your array and carbo the 3rd.
$resA = 2 * $a[2] + 3 * $a[3];
$resB = 2 * $b[2] + 3 * $b[3];
if ($resA == $resB)
return 0;
return ($resA < $resB) ? -1 : 1;
}
usort($info, "sort2Protein3Carbo");
Related
I have the following SQL statement:
$query = "SELECT item, COUNT(*) as number FROM shop GROUP BY item";
This will give me the following result:
item number
item1 23
item2 15
item3 4
I want to use this to make menu items, so normally the menu would look:
item1
item2
item3
But I want to do a check if an item has less than 10 records, that I don't want to display this item.
So in this example, the menu would be like:
item1
item2
Any idea how to achieve this?
I would like to do this in PHP because I need all the items in the query but will only want to show them which are greater then 10 and need the other items later on.
If you want to do this in PHP then you can do like this
function filterArray($value){
return ($value.number > 10);
}
$filteredArray = array_filter($yourDBArray, 'filterArray');
foreach($filteredArray as $k => $v){
//your desired array
}
In terms of speed Mysql option is good as suggested above.
Just change your query from
SELECT item, COUNT(*) as number FROM shop GROUP BY item
to
SELECT item, COUNT(*) as number FROM shop GROUP BY item HAVING number>=10
As you really need to perform this in PHP you could use array_filter() which, using a closure, will remove items which number is less than 10:
$more_than_ten = array_filter($items, function ($i) { return $i['number'] >= 10; });
Doing it with SQL would be a better solution (about performances). In case you'd need it, you could use the HAVING clause (you can't perform a WHERE number >= 10):
SELECT
item,
COUNT(*) as number
FROM shop
GROUP BY item
HAVING number >= 10
I noticed php is tagged. For the sake of options, here's how I'd go about separating the unneeded data in php if you were to get it from the database as-is:
foreach ($data as $item) {
$num = (int) $item['number']; // force of habit
if ($num >= 10) {
// display it
}
}
I'd probably separate the data at the database step, but this works if it's the route you want to take.
There is two options to filter the data so only the rows with more then 10 will appear.
At the SQL query
__
SELECT item, COUNT(*) as number FROM shop GROUP BY item HAVING number > 9
This will cause you to recieve only the requested rows from the database
Filter with PHP - every time you want to print the menu or testing it out, just can the value of 'number' in the array reutrned from the query. You can also allocate new array and insert all the values that contains 'number' that bigger then 10.
Can't seem to get my head around of sorting laravel collection so empty / null data would end up being last. ( bit confused about usort )
Pretty much all I have is bunch of times / timestamps that need to be ordered. Some rows may not have for that column.
I would like data to appear ASC / ascending while empty/null data is shown last.
$collection->sortBy('timestamp') sorts nicely but doesn't know how to deal with empty fields.
Table looks like this.
$data = $data->sort(function($a, $b) use ($sortBy) {
if ($a->{$sortBy} and $b->{$sortBy}) return 0;
return ($a->{$sortBy} > $b->{$sortBy}) ? -1 : 1;
});
Random code I tried from the internet, which I can't get to work correctly.
$sortBy contains a field name to sort by ( since it may change )
Faulty code deals with empty / null data but its out of order.
Have to use sort() with a closure. Below will sort timestamp ASC with NULL at the end.
$sorted = $collection->sort(function ($a, $b) {
if (!$a->timestamp) {
return !$b->timestamp ? 0 : 1;
}
if (!$b->timestamp) {
return -1;
}
if ($a->timestamp == $b->timestamp) {
return 0;
}
return $a->timestamp < $b->timestamp ? -1 : 1;
});
Try:
$collection->sortBy('-timestamp')
Does it work?
I had a similar issue. In my case, the time attribute of a $result might be NULL. It acts as if NULL is 0 (as int) and that's expected behavior. But I also wanted to sort the collection by leaving NULL last.
$collection->sortBy(function ($result) {
if ($result['time'] === NULL) {
return PHP_INT_MAX;
}
return $result['time'];
});
You can achieve this simply by returning an value higher in the alphabetical order compared to all other values in the array. i.e. PHP_INT_MAX to be safe. This will make sure all the results where the time equals NULL are at the end of the array.
Similar to Mr. Speelman's solution, but as a shorter PHP 7.4+ version:
$collection->sortBy(fn($e) => $e->timestamp ?: PHP_INT_MAX)
I assume your timestamp is unix timestamp.
You can sort it like this :
$sorted = $collection->sortByDesc('timestamp');
This question already has answers here:
Preserve key order (stable sort) when sorting with PHP's uasort
(6 answers)
Closed 5 months ago.
I'm using usort to sort an array of objects, but really I want this to act as a kind of "group by" function without disturbing the original relative order of the rows.
Say I have this:
MASTER_CODE, CONFIG_ITEM
foo1, opt_ray
foo2, opt_ray
foo1, opt_fah
foo2, opt_doe
From that data, an array of objects is constructed with an anonymous key. That is, each row is parsed as an object. The objects are collected into an array.
What I want to do is sort the array by the MASTER_CODE value, but without disturbing the order.
That is, the final order should be:
MASTER_CODE, CONFIG_ITEM
foo1, opt_ray
foo1, opt_fah
foo2, opt_ray
foo2, opt_doe
We don't add a sort order, because the data comes from an external source.
I can use usort to order by the master code, but it messes up the original relative order.
Any suggestions?
This is one option - it's not the most elegant solution. It will take the unique values from the first column of your array (the one you want to filter by), sort that, then loop it and add entries from your original array with the same first value.
// Get an unique array of values to use for sorting
$sorting = array_unique(array_column($a, 0));
sort($sorting);
$sorted = [];
foreach ($sorting as $sortValue) {
$sorted = array_merge(
$sorted,
array_filter(
$a,
function($row) use ($sortValue) {
// Find values that have the same first value as each sort value
return ($sortValue === $row[0]);
}
)
);
}
Example
Note: This will work on PHP 5.5. Since you also tagged PHP 5.3, you may need to replace the array_column function. Try something like this:
$sorting = array_unique(array_map(function($row) { return $row[0]; }, $a));
I have a symfony problem: The functionally works good, but this does not work the way I want.
$res = array("4","2","1","3"); // LIST ID (a.id)
$paginas = new sfDoctrinePager('TbArticle', 2);
$paginas->setQuery(Doctrine::getTable('TbArticle')->createQuery('a')->where('a.ifactive = 1')->andWhere('a.dirimage=1')->andWhere('a.stock<>0')->whereIn("a.id", $res));
$paginas->setPage($page);
$paginas->init();
It works okay, but when I call getResults(), the array order is incorrect. For instance, this sort returns: 1,2,3,4. And I like to get: 4, 2, 1, 3 ($res)
Can you help me?
Unfortubately this cannot be done with the query.
The MySQL queries can be returned ordered using the ORDER BY clause in ascending or descending order. Elements in your array use none. When you pass the array as a parameter for the WHERE IN clause MySQL doesn't care about the order of the elements as you can see.
Fortunately there is a solution :)
First you will have to use Doctrine's ability to create a table of results indexed with what you want. Use this:
Doctrine::getTable('TbArticle')->createQuery('a INDEX BY id')->...;
This will return an array of results where the array keys are the id's of the rows. Then you can rearange the results array to match your $res (assuming that $rows has the rows returned by Doctrine):
foreach ($res as $i) {
$new_array[] = $rows[$i];
}
The tricky part is to make it work with the paginator. But I'm sure you can do that as well (try to retrieve the results from the paginator and rearange them before displaying).
Using Sphinx 2.0.6, is there a way to have sphinx return a specific order based on the document ID?
For example, say there are 1000 documents all having id 1-1000. But I want to return, in order, ID 999,1000,4,5,2,and so on.
This use case: The positioning is dynamic and needs to be done through Sphinx. The positioning value needs to be as an attribute that can change on-the-fly. This is also paged -- so I can't simply gather the ID Set and request a SQL. Sphinx itself needs to return the specific order I give it.
$cl->setSelect("*,FIND_IN_SET(id,".implode($id_array).") AS id_position");
$cl->SetSortMode(SPH_SORT_EXTENDED, 'id_position DESC');
$cl->setSelect("*,FIELD(id,".implode($id_array).") AS id_position");
$cl->SetSortMode(SPH_SORT_EXTENDED, 'id_position DESC');
Unfortunately, doesn't look like Sphinx supports FIELD() and FIELD_IN_SET().
Any ideas how to complete this task? I'm at a loss right now and could use the help!
Do you need to use that array structure?
With Sphinx you can use an "ORDER BY id" statement and then when getting results use:
$cl->SetSortMode( SPH_SORT_ATTR_DESC, "id" );
Figured it out thankfully! This is an excellent solution to being able to order by a dynamic id array. (real world use... user's favorites, recommended products, user's most visited)
Sphinx PHP Code:
$cl->SetOverride("id_position", SPH_ATTR_INTEGER, user_id_position());
$cl->SetSortMode(SPH_SORT_EXTENDED, "id_position ASC");
PHP Function to create the associative array:
function user_id_position() {
$id = $_original_id_list // This variable is the original id list that is in the correct order
$max = count($id);
$set = array();
for ($i=0;$i < $max;$i++)
$set[$id[$i]] = $i; // turns the array into array(document_id1 => position, document_id2 => position, ...)
return $set;
}
sphinx.conf
source index_name
{
sql_query = \
SELECT \
*, 0 as id_position \
FROM \
database_table;
sql_attr_uint = id_position
}
After adding the information to sphinx.conf you'll need to --rotate and it'll work