PHP array_push overwriting the pushed data - php

I seeing a rare behavior of the array_push php function. It's like when I'm looping through the result rows of the query and pushing the complete array of data into a 'parent' array ($rdo), the values are beeing modified with the ones of the last row added.
This is my code:
$rdo = array();
if($sentencia = $general_con->prepare("SELECT monthly_price, name FROM subscription_plan WHERE deleted=0"))
{
$sentencia->execute();
$sentencia->store_result();
$num_of_rows = $sentencia->num_rows;
$sentencia->bind_result($row['monthly_price'], $row['name']);
while($sentencia->fetch())
{
array_push($rdo, $row);
echo print_r($rdo,1).'<br/><br/>';
}
$sentencia->close();
die();
}
And this is the result:

It looks like this is an artifact of the way bind_result() uses references to the array elements. When you push $row onto $rdo, this is updating all those array elements.
I recommend you move away from using bind_result() and use fetch_assoc().
if($sentencia = $general_con->prepare("SELECT monthly_price, name FROM subscription_plan WHERE deleted=0"))
{
$sentencia->execute();
$result = $sentencia->get_result();
while($row = $result->fetch_assoc())
{
array_push($rdo, $row);
echo print_r($rdo,1).'<br/><br/>';
}
$sentencia->close();
die();
}

Related

Array push rows from SQL query

I am trying to save the rows (results) from an SQL query to a csv file.
I am using array push in order to put the results in a list. Later I put the data from this list to my csv file.
My code :
while ($row = $query->fetch_assoc())
{
echo sprintf( $row['campaign']);
array_push($list, $row['campaign']);
}
The results are there because sprintf works. The problem is with the syntax of array_push. I even tried :
array_push($list, array(''.$row['campaign']);
I am getting an error:
fputcsv() expects parameter 2 to be array
The full code is here :
$list = array
(
array('old_campaign_name', 'new_campaign_name')
);
// table 1
$sql = ('select distinct(campaign) as campaign from '.$table1.'');
// Run the query
$query = $Db->query($sql);
// Check for SQL errors
if ($Db->error)
{
return ($Db->error);
}
// Put data in the list
while ($row = $query->fetch_assoc())
{
echo sprintf( $row['campaign']);
array_push($list,$row['campaign'],'');
}
$fp = fopen($location, 'w');
foreach ($list as $fields)
{
fputcsv($fp, $fields);
}
fclose($fp);
As the error says, fputcsv expects each row that you put to be an array, so it can write it out with commas separating the elements. $list should be a 2-dimensional array, so you need to push an array onto it when you're building it.
while ($row = $query->fetch_assoc() {
$list[] = array($row['campaign']);
}
BTW, $list[] = x is equivalent to array_push($list, x).
When you initially create the $list array, it is an array containing one array. But when you add more values to it from your query results, you are pushing strings onto the end of it, not arrays. In effect, you will be making something like
$list = array (
array('old_campaign_name', 'new_campaign_name'),
'first campaign',
'second campaign',
'etc.',
...
);
Because of this, when you loop over $list, the first value should work with fputcsv, because it is an array, but any subsequent values will be strings instead of arrays and will cause the error you are seeing.
You should be able to fill the $list like this:
while ($row = $query->fetch_assoc()) {
$list[] = $row;
}
$list[] = $row will not overwrite the values previously in $list. From the PHP documentation for array_push:
Note: If you use array_push() to add one element to the array it's better to use $array[] = because in that way there is no overhead of calling a function.
It works like this :
while ($row = $query->fetch_assoc())
{
// array_push($list,$row['campaign'],'');
array_push($list,array($row['campaign'], ''));
}

Storing db value into php array and then looping through the array

What would the benefits be of storing db values into an array and then looping through the array vs just using a while loop?
Outputting db results to an array:
$records = array();
if($results = $db->query("SELECT name, address FROM town")) {
if($results->num_rows) {
while($row = $results->fetch_object()) {
$records[] = $row;
}
$results->free();
}
}
Loop through array:
foreach($records as $r) {
$r->name;
}
VS a simple While loop:
if($result = $db->query("SELECT name, address FROM town")) {
if($count = $result->num_rows) {
while($row = $result->fetch_object()) {
echo $row->name, ' ', $row->address, '<br />';
}
$result->free();
}
}
Just a while loop and printing the result is easy and fast, but in certain times you want to do more then just print the array and then it becomes handy if you already work with arrays.
The most common use for this is freeing the resultset, allowing you to perform other db queries (updates, inserts...) before actually making any use of the results you got in the first place.

While loop showing only one result

I want to show string outside while loop, but it only shows one result.
while($row = $result->fetch_assoc()) {
$myarr = array();
}
echo $myarr;
This shows only one result but I need all the results outside the while loop.
Could you please help me how is this possible?
I am not sure if you want the whole row returned from the query or just a single field.
If its the whole row then try
$myarr = array(); // initialize
while($row = $result->fetch_assoc()) {
$myarr[] = $row;
}
print_r($myarr);
This will give you an array containing n row arrays.
Problem :
You are just assigning the result one after again
$myarr = array();
Here, It means you're assigning the array() again and again, which replaces the old value
Solution / What You should do
1. You can assign it to an Array (Good Approach)
while($row = $result->fetch_assoc()) {
$myarr[] = $row['yourdbitem']; // or $row if you want whole row
}
print_r($myarr);
2. You can concat in each iteration (Bad Approach)
$somevariable = '';
while($row = $result->fetch_assoc()) {
$somevariable .= $row['yourdbitem']; // or $row if you want whole row
}
echo $somevariable
Note :
I have given good and bad approach to updating what you should do and what you should not do :)

PHP - Multidimensional Array

I am basically trying to fetch results from a SQL database and load that into a multidimensional array so i can use them later on in the page.
while($row = mysqli_fetch_array($result))
{
$send = array
(
array($row['Name'],$row['Email'],$row['Mobile'])
);
$count = $count + 1;
}
That is what i am using to get the results which if i print within the while loop it will echo all the results. However when putting it into the array it loads each result into the array as the first result. My initial plan was to use a counting variable to set where in the array the result was set to with this adding by one each time. I am not certain how to specify where to add the result i thought something along the lines of
$send = array[$count]
(
array.....
so i could then refer to the results as 0 to count length but i am not sure how to make this work. Or ,which i presume, if there is a much easier and better way of going about it. I am also not sure if this is necessary as surely the results seem to be in an array when gathered from the SQL database but i am unsure if this array is populated with each while loop or stored and can be accessed at any point
If any one can give me an example of something similar or point me at some documentation much appreciated
Try this:
$count = 0;
while ($row = mysqli_fetch_array($result)) {
$send[$count] = array($row['Name'], $row['Email'], $row['Mobile']);
$count++;
}
I have a better way for you. You could also use the id for your index, if you have one:
while ($row = mysqli_fetch_array($result)) {
$send[$row['id']] = array(
"Name" => $row['Name'],
"Email" => $row['Email'],
"Mobile" => $row['Mobile']
);
}
You can use:
$count = 0;
while($row = mysqli_fetch_array($result))
{
$send[$count] = $row;
$count ++;
}
Also you might want to use the table id as an array index, so you can access the records by ID later. In that case you can do:
while($row = mysqli_fetch_array($result))
{
$send[$row['id']] = $row;
}
You're declaring your array inside your loop. So it will reset it every time.
$send = array();
while($row = mysqli_fetch_array($result))
{
$send[] = array($row['Name'],$row['Email'],$row['Mobile']);
}

How to select multiple rows from mysql with one query and use them in php

I currently have a database like the picture below.
Where there is a query that selects the rows with number1 equaling 1. When using
mysql_fetch_assoc()
in php I am only given the first is there any way to get the second? Like through a dimesional array like
array['number2'][2]
or something similar
Use repeated calls to mysql_fetch_assoc. It's documented right in the PHP manual.
http://php.net/manual/function.mysql-fetch-assoc.php
// While a row of data exists, put that row in $row as an associative array
// Note: If you're expecting just one row, no need to use a loop
// Note: If you put extract($row); inside the following loop, you'll
// then create $userid, $fullname, and $userstatus
while ($row = mysql_fetch_assoc($result)) {
echo $row["userid"];
echo $row["fullname"];
echo $row["userstatus"];
}
If you need to, you can use this to build up a multidimensional array for consumption in other parts of your script.
$Query="select SubCode,SubLongName from subjects where sem=1";
$Subject=mysqli_query($con,$Query);
$i=-1;
while($row = mysqli_fetch_array($Subject))
{
$i++;
$SubjectCode[$i]['SubCode']=$row['SubCode'];
$SubjectCode[$i]['SubLongName']=$row['SubLongName'];
}
Here the while loop will fetch each row.All the columns of the row will be stored in $row variable(array),but when the next iteration happens it will be lost.So we copy the contents of array $row into a multidimensional array called $SubjectCode.contents of each row will be stored in first index of that array.This can be later reused in our script.
(I 'am new to PHP,so if anybody came across this who knows a better way please mention it along with a comment with my name so that I can learn new.)
This is another easy way
$sql_shakil ="SELECT app_id, doctor_id FROM patients WHERE doctor_id = 201 ORDER BY ABS(app_id) ASC";
if ($result = $con->query($sql_shakil)) {
while ($row = $result->fetch_assoc()) {
printf ("%s (%s)\n", $row["app_id"], $row["doctor_id"]);
}
Demo Link
It looks like the complete solution has not been suggested yet
$Query="select SubCode,SubLongName from subjects where sem=1";
$Subject=mysqli_query($con,$Query);
$Rows = array ();
while($row = mysqli_fetch_array($Subject))
{
$Rows [] = $row;
}
The $Rows [] = $row appends the row to the array. The result is a multidimensional array of all rows.

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