PHP Array Unsetting Help

[AJLX]

Hi Guys,

 

I have an array that looks like this:

 

 

 

Array
(
[0] => Array
(
[0] => Header1
[1] => Header2
[2] => Header3
[3] => Header4
[4] => Header5
[5] => Header6
[6] => Header7

)

[1] => Array
(
[0] =>value1
[1] =>Value2
[2] =>Value3
[3] => Value4
[4] => Value5
[5] => Value6
[6] =>Value7

)

[2] => Array
(
[0] =>value1
[1] =>Value2
[2] =>Value3
[3] => Value3
[4] => Value4
[5] => Value5
[6] => Value6

)

 

It has come from a CSV file. Basically, I only need to use some of the columns, the rest can be unset/deleted. Is there a way that I can easily make an array that just has for example "header1" and "header5" and the corresponding values "value1" and "value5"?

 

I don't know what order the columns are going to be in, so I need to somehow do it by name. I think I know the concept of what to do, I just lack the php knowledge to actually do it!

 

I think I need to:

 

Step 1:
Loop through the array and get the array keys that match up to the headers above

 

Step 2:
reload through the array unsetting based on the array keys found in step 1

 

I've tried looking into array_intersect and array_diff but I can't work out how these would help.

 

Thanks for reading!

 

 

 

 

[requinix]

What's your code to read the CSV file? It'll be easier to just change that to work how you want.

[benanamen]

This sounds like an XY problem. What exactly is it you are doing? And I don't mean your attempt at it.

[Sepodati]

If you don't need them, don't put them into the array in the first place. I agree with the above, too. What's the real problem you're trying to solve / system you're trying to create? Maybe there's a better way to do this from the very start.

 

-John

Edited August 30, 2017 by Sepodati

[requinix]

I wanted to see code first but if this is how the thread is going,

$csv = array(
	explode(",", "h2,h4,h1,h3"),
	explode(",", "r1c2,r1c4,r1c1,r1c3"),
	explode(",", "r2c2,r2c4,r2c1,r2c3"),
	explode(",", "r3c2,r3c4,r3c1,r3c3")
);

/* $h = fopen("file.csv", "rt"); */
/* $header = fgetcsv($h);        */ $header = array_shift($csv);

/* while (!feof($h)) {           */
/*	$row = fgetcsv($h);      */ foreach ($csv as $row) {

	$hrow = array_combine($header, $row);
	echo "c1 = ", $hrow["h1"], "\n";

}

[AJLX]

Hi All,

 

Thanks for the response so far. This is from a file that built about a year ago, I've come to update it. The original code uploaded the file, put it into an array, and then deleted the file. The more I think about it, the more I think that's a pointless step? The CSV sent from a previous page.

 

The aim of the code is to take the data from a .csv file, extract the columns that I want, and store them into a database, for retrieval later. I know the names of the columns that I want to keep, but the maker of the software version keeps updating how they export the data, and adding columns which I can ignore. My current upload code is below. I think it was taken from a tutorial that I found ages ago. Now that I know a little bit more about PHP(!) I'm trying to understand more efficient ways of working!

 

 

$target_dir = "csv/";

$target_file = $target_dir . basename($_FILES["fileToUpload"]["name"]);

$uploadOk = 1;

$imageFileType = pathinfo($target_file,PATHINFO_EXTENSION);

// Check if image file is a actual or fake image

 

if(isset($_FILES["fileToUpload"])) {

// Check file size

if ($_FILES["fileToUpload"]["size"] > 500000) {

exit ("Sorry, your file is too large.");

$uploadOk = 0;

}

// Allow certain file formats

if($imageFileType != "csv" ) {

exit ("Sorry, only CSV files are allowed.");

$uploadOk = 0;

}

// Check if $uploadOk is set to 0 by an error

if ($uploadOk == 0) {

exit ("Sorry, your file was not uploaded.");

// if everything is ok, try to upload file

} else {

if (move_uploaded_file($_FILES["fileToUpload"]["tmp_name"], $target_file)) {

echo "The file ". basename( $_FILES["fileToUpload"]["name"]). " has been uploaded.";

$file = basename($_FILES["fileToUpload"]["name"]);

} else {

exit ("Sorry, there was an error uploading your file.");

}

}

 

ini_set('auto_detect_line_endings', TRUE);

$rows = array_map('str_getcsv', file('csv/'.$file));

 

echo "<pre>";

print_r($rows);

echo "</pre>";

$header = array_shift($rows); // Strip out the colum headers from the CSV

$csv = array();

 

//print_r($rows);

 

foreach ($rows as $row) {

//loop through, manually unset the rows that I don't want, and format, and assign variables to the rows that I want to keep

}

 

Once again- Thanks!

[requinix]

Instead of the file+array_map, do a normal fopen/fgetcsv/fclose loop - which also replaces the foreach. And there's another way to get values that might work better for you.

$h = fopen('csv/'.$file, 'rt');
$header = array_flip(fgetcsv($h)); 0=>header1 becomes header1=>0
while (!feof($h)) {
	$line = fgetcsv($h);
	$value1 = $line[$header["header1"]];
	$value3 = $line[$header["header3"]];
	// etc
}
fclose($h);

[AJLX]

Hi Lazy Administrator,

 

Thanks for your help (and patience!) so far. The code you posted doesn't seem to work for me. If I Print_R the $header array, that contains all of the headers, and looks as I expect it should. However, when I Print_R the $line array, the keys are numbered, they don't have the same titles as the header array, so therefore the:

 

 

 

$value1 = $line[$header["header1"]];

 

comes back with an undefined index error. I thought that I could use array_combine to put the headers back into where I think they should be:

 

 

$h = fopen('csv/'.$file, 'rt');

$header = fgetcsv($h);

$flip_header = array_flip(fgetcsv($h)); //0=>header1 becomes header1=>0

 

while (!feof($h)) {

$line = fgetcsv($h);

 

$new = array_combine($header,$line);

print_r($new);

 

$unit = $new[$flip_header["Unit"]];

 

 

}

fclose($h);

 

Now the array looks how I think it should but still doesn't work. Therefore I clearly don't understand how it should look/work!

 

Thanks!

[requinix]

Well with that code, you would have to do

$unit = $line[$flip_header["Unit"]];

The alternative with array_combine would be to ignore $flip_header entirely (it turns names into numbers) and

$unit = $new["Unit"];

But I recommend the $flip_header one.

[AJLX]

Hi Lazy Administrator,

 

I'm still struggling with this one! I'm onto about my 10th generation of code which looks like this:

 

 

$h = fopen('csv/'.$file, 'rt');

$header =fgetcsv($h); //0=>header1 becomes header1=>0

while (!feof($h)) {

$line = fgetcsv($h);

$new_arr = array_combine($header,$line);

print_r($new_arr);

 

echo $new_arr["Unit"];

 

//print_r(array_keys($new_arr));

}

fclose($h);

 

 

That gives me the following output:

 

 

The Array key "Unit" exists, but for some reason doesn't seem to get found. I tried running  print_r(array_keys($new_array) to try and investigate the array keys a bit further, with this result 

 

 

I've played about with adding some spaces to the word Unit to see if that would help, but it doesn't seem to make a difference. It's getting late here, and I'm getting the feeling I've done something that's super simple, but stupid!

[requinix]

That output did not come from print_r(array_keys($new_arr)).

 

What does var_dump($new_arr) show?

[AJLX]

That output did not come from print_r(array_keys($new_arr)).

 

What does var_dump($new_arr) show?

 

 

The bottom screenshot clearly doesn't! I must have uploaded the wrong file. I'll leave it there to keep the thread complete. Here is the ACTUAL output, and the the Var_dump afterwards. There's weird characters being exported in the channel column, but as far as I can tell, that's the only key that's effected. I should be able to clean that up easy enough. Any ideas?

 

 

 

 

 

Many thanks

[requinix]

Take a look at some of those values:

string(1) ""
string(7) "O/W"
string(3) "0"

Weird, right?

 

What is the file encoding of the CSV?

 

What does

print_r(array_combine($header, array_map("bin2hex", $header)));

output? And please, don't take a screenshot: do a View Source of the page and copy/paste the formatted text into a [code] in a post.

[AJLX]

Hi Requinix,

 

The file is natively exported as a UTF-16. I re-saved it as a UTF-8 and it all works perfectly. Does PHP have the ability to be able to convert the file for me? 

[requinix]

Assuming you're using UTF-8 in the rest of your application then yes.

 

Try adding

stream_filter_append($h, "convert.iconv.utf-16.utf-8");

after the fopen().

 

Does it work now? Does the first header "Channel" still have the two >s (the UTF-16 BOM)?

[AJLX]

That works perfectly- Thanks for your help- I've learnt lots!