Filtering large array from SQL result

Filtering large array from SQL result - php

Some important notes:
Validate any user input
NEVER execute SQL in a loop
Use one query that fetches everything you need (you're using the same table)
Fetch an associative array, this will help you a lot
Specify exactly what you need in your projection (not * after SELECT, exactly state each field to fetch like SELECT foo, bar, …)
Here is some code to help you get started with the above tips:
<?php
// Validate input, please note that prepared statements would be best.
// Also note that we don't need mysql escape calls because we validate
// that this is an actual integer value which can't contain anything
// dangerous. If we'd be working with any kind of string, date, ... the
// world would look different.
if (!is_array($userID)) {
if (!is_int($userID)) {
throw new \RuntimeException;
}
$userIds = "= {$userID}";
}
else {
$userIds = null;
$c = count($userID);
for ($i = 0; $i < $c; ++$i) {
if (!is_int($userID[$i])) {
throw new \RuntimeException;
}
$userIds .= $userIds ? "," : "IN(";
$userIds .= $userID[$i];
}
$userIds .= ")";
}
// One query to rule them all and nice formatting for readability.
$result = $link->query(
"SELECT *
FROM `wp_usermeta`
WHERE `meta_key` = 'purchased_instances'
AND `user_id` {$userIds}"
);
// Now we fetch everything within a single loop.
while ($row = mysqli_fetch_assoc($result)) {
print_r($row);
}
// That's it!
mysqli_free_result($result);
?>

Related

Get Data from database using array values with for loop in PHP

Array:
$ecodesAr = Array (
[0] => 1Z0-060
[1] => 98-375
[2] => 98-368
[3] => 98-367 )
for($k=0; $k<count($ecodesAr); $k++){
$arrayTB[$k] = $this->Functions->exam('title', $ecodesAr[$k]); }
Modal code:
public function exam($q, $d) {
$q = $this->db->where($q, $d)
->get('exams');
return $q->row();
}
Result:
Array (
[0] =>
[1] =>
[2] =>
[3] => stdClass Object ( [id] => 1091 [hot_exam] => 0 [top_exam] => 0 [category] => 114 [subcats] => 288 [slug] => 98-367 [sku] => OI5Ao [title] => 98-367 [name] => MTA Security Fundamentals [update] => 2021-09-16 [regular_price] => 130 [sale_price] => 59 [on_homepage] => 0 [on_request] => 0 [expired] => 0 [path_slug] => 98-367.pdf [questions] => 123 [demo_slug] => 98-367-demo.pdf [prc_price] => 65 [prc_demo] => 98-367-demo [prc_exam] => 98-367 [is_active] => 1 )
)
The First 3 values are skiped in the output and just the last value got, I want to all array data against values please help anyone!

$productsarry = Array (
[0] => Milk
[1] => Cream
[2] => Sugar
[3] => Yougert
);
for($k = 0; $k < count($productsarry); $k++) {
$arrayTB[$k] = query("select slug, qty, name, price from exams where title ='$ecode'")->row();
}

Array and Mysql insert using PDO

connect arrays into one

How i can transform this first array [ONE}: Into second array [TWO} where i can call meta_key and than i get var: i get this array by calling specified sql rows and i am using this query: $user_data = $wpdb->get_results("SELECT * FROM $wpdb->usermeta WHERE user_id = $fivesdraft->user_id "); maybe its another better way to connect it in query? not in PHP
Array ONE
(
[0] => stdClass Object
(
[umeta_id] => 16
[user_id] => 2
[meta_key] => nickname
[meta_value] => user1
)
[1] => stdClass Object
(
[umeta_id] => 17
[user_id] => 2
[meta_key] => first_name
[meta_value] => testname
)
[2] => stdClass Object
(
[umeta_id] => 18
[user_id] => 2
[meta_key] => last_name
[meta_value] => testlastname
)
[3] => stdClass Object
(
[umeta_id] => 19
[user_id] => 2
[meta_key] => description
[meta_value] => user desc
)
)
Array TWO
(
[nickname] => 'user1'
[first_name] => 'user desc'
[last_name] => 'user desc'
[description] => 'user desc'
...
)

You can use array_reduce:
$myArray = array_reduce($arrayOne, function ($result, $item) {
$result[$item->meta_key] = $item->meta_value;
return $result;
}, array());

Just loop over the array and write the values in a new array
$two = array();
foreach ($one as $item) {
$two[$item->meta_key] = $item->meta_value;
}

Creating a multidimensional array using an array and loop through mysql table

I have a table with the following structure. There are currently 9 students enrolled in 3 classes (classes 01, 16 and 52), with 3 enrollments in each class.
studentcode | classcode
-------------------------
D3kcIvyp | 01
DdIhBc | 01
2vx0KV | 01
9p1PxWCV | 52
RnmfH1WE | 52
MSTBEv | 52
Yp4J3o | 16
fWQ5Oo | 16
6sxw3u | 16
This is the array with all current classes:
$classes_array = array ( [0] => 01 [1] => 52 [2] => 16 )
Using this array I would like to go through the mysql table and create a multidimensional array with the classcodes used as first level keys:
Array
(
[01] => Array
(
[0] => D3kcIvyp
[1] => DdIhBc
[2] => 2vx0KV
)
[52] => Array
(
[0] => 9p1PxWCV
[1] => RnmfH1WE
[2] => MSTBEv
)
[16] => Array
(
[0] => Yp4J3o
[1] => fWQ5Oo
[2] => 6sxw3u
)
)
foreach ($classes_array as $key => $value)
{
$sql = "SELECT studentcode FROM table WHERE classcode = '$classes_array[$key]'";
$result = mysql_query($sql) or die();
while($data = mysql_fetch_array($result))
{
$studentcodes_array[] = $data['studentcode'];
}
foreach ($studentcodes_array as $studentcodeskey => $studentcodesvalue)
{
$multid_array[$value][] = $studentcodesvalue;
}
}
Using the code above, unfortunately I don't get the array I would like to get. I get this instead:
Array
(
[01] => Array
(
[0] => D3kcIvyp
[1] => DdIhBc
[2] => 2vx0KV
)
[52] => Array
(
[0] => D3kcIvyp
[1] => DdIhBc
[2] => 2vx0KV
[3] => 9p1PxWCV
[4] => RnmfH1WE
[5] => MSTBEv
)
[16] => Array
(
[0] => D3kcIvyp
[1] => DdIhBc
[2] => 2vx0KV
[3] => 9p1PxWCV
[4] => RnmfH1WE
[5] => MSTBEv
[6] => Yp4J3o
[7] => fWQ5Oo
[8] => 6sxw3u
)
)
What is wrong with my code? Can anybody help me with this?

You never initialise $studentcodes_array so it is remembering all the values from your previous loops.
Try adding $studentcodes_array = array(); before your while.

How to group elements of array using Primary and secondary key?

I've got this array:
Array
(
[0] => Array
(
[id]=>1
[account_id] => 1
[object_id] => 43
[object_type] => PHOTO
[action_type] => UPLOAD_PHOTO
)
[1] => Array
(
[id] => 1
[account_id] => 1
[object_id] => 42
[object_type] => PHOTO
[action_type] => UPLOAD_PHOTO
)
[2] => Array
(
[id] => 1
[account_id] => 1
[object_id] => 41
[object_type] => PHOTO
[action_type] => UPLOAD_PHOTO
)
[3] => Array
(
[id] => 2
[account_id] => 2
[object_id] => 1
[object_type] => USER
[action_type] => FOLLOW_USER
)
[4] => Array
(
[id] => 1
[account_id] => 1
[object_id] => 2
[object_type] => USER
[action_type] => FOLLOW_USER
)
[5] => Array
(
[id] => 1
[account_id] => 1
[object_id] => 1
[object_type] => PHOTO
[action_type] => UPLOAD_PHOTO
)
)
Now I want to group elements have same value (for example UPLOAD_PHOTO) by id as Primary Key and action_type as Secondary Key, like:
Array
(
[0] => Array(
[id] => 1
[account_id] => 1
[actions] => array(
[1] => array(
[object_id] => 42
[object_type] => PHOTO
[action_type] => UPLOAD_PHOTO
)
[2] => array(
[object_id] => 43
[object_type] => PHOTO
[action_type] => UPLOAD_PHOTO
)
)
)
[2] => Array
(
[id] => 1
[account_id] => 1
[actions] = array(
[0] => Array
(
[object_id] => 3
[object_type] => USER
[action_type] => FOLLOW_USER
)
[1] => Array
(
[object_id] => 4
[object_type] => USER
[action_type] => FOLLOW_USER
)
)
)
)
I tried some solutions but didn't succeed.

When constructing your output array, you'll want to use meaningful array keys. That way you can find the out element that the in element needs to be added to:
$in = (...your array...);
$out = array();
foreach($in as $element) {
$id = $element['id'];
//If that id hasn't been seen yet, create the out element.
if (!isset($out[$id])) {
$out[$id] = array(
'id'=>$element['id'],
'account_id' => $element['account_id'],
'actions' => array()
);
}
//Add that action to the out element
$out[$id]['actions'][] = array(
'object_id' => $element['object_id'],
'object_type' => $element['object_type'],
'action_type' => $element['action_type']
);
}
I'm not sure why your input elements have different fields... If this is a desired feature, where one set of possible fields belongs to the id group and another set belongs to the action, you can do this instead (slightly less readable, but more flexible):
$in = (...your array...);
$out = array();
//These define which fields from an
//input element belong to the id,
//and which to the action.
$id_fields = array_flip(array('id','account_id','object_user_id');
$action_fields = array_flip(array('object_id','object_type','action_type');
foreach($in as $element) {
$id = $element['id'];
//If that id hasn't been seen yet, create the out element.
if (!isset($out[$id])) {
$out[$id] = array_intersect_key($element, $id_fields);
$out[$id]['actions'] = array();
}
//Add that action to the out element
$out[$id]['actions'][] = array_intersect_key($element, $action_fields);
}
This is a better solution if the input elements can be different, because if an expected field (other than 'id') is missing, the script will cope with it easily.

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Filtering large array from SQL result - php

Related

Get Data from database using array values with for loop in PHP

Array and Mysql insert using PDO

connect arrays into one

Creating a multidimensional array using an array and loop through mysql table

How to group elements of array using Primary and secondary key?

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