PHP - Submitting Data To Txt File From Textarea

Hello everyone!

I've been on a problem a few hours now and I've managed to finally find the solution however I feel it's very inefficient and am looking for a way to do this in a better way.

I have a textarea where each line is inserted into MySQL database table "lines" and I have the columns "line_number" and "row".

The textarea initial value on page load is simply a list of all lines ordered by line_number in ASC order.

If I modify/add/remove entries from the textarea it will remove data changed and add new data accordingly.

But I am making a lot of queries to do this and I'm not sure if there is a more efficient way than querying each line in the database to find the new value/modified value.

Here's my php script, hopefully this makes sense:

if (isset($_POST['lines'])) {
    
    //get lines posted from textarea
    $lines_posted = $_POST['lines'];
    
    //trim all white spaces and remove empty lines as they are not valid for mysql insert
    $lines = trim($lines_posted);
    $lines = explode("\n", str_replace("\r", "", trim($lines_posted)));
    $lines = array_map('trim', $lines_posted);
    $lines = array_filter($lines_posted);
    
    $line_count = count($lines);
    //output how many valid lines were posted
    echo "Posted Lines: $line_count<br>";
    
    //loop through all lines posted, query all rows in database and insert if lines row value does not exist
    for ($i = 0; $i < $line_count; $i++) {
        if (isset($lines[$i])) {
            $find_line_in_db = $db->query("SELECT row FROM lines WHERE row=?", $lines[$i]);
            if ($find_line_in_db->numRows() == 0) {
                $db->query("INSERT INTO lines (line_number, row) VALUES (?,?)", $i, $lines[$i]);
                echo 'Added the line: ', htmlspecialchars($lines[$i]), '<br>';
            }
        }
    }
    
	//query all rows in the database and check if posted lines array value is in the [row] column, delete rows changed/not found accordingly
    $rows             = "";
    $fetch_all_lines  = $db->query("SELECT row FROM lines");
    while ($all_lines = $fetch_all_lines->fetchRow()) {
        if (!in_array($all_lines['row'], $lines)) {
            $rows = $all_lines['row'];
            $db->query("DELETE FROM lines WHERE row=?", $all_lines['row']);
            echo 'Deleted the line: ', htmlspecialchars($lines[$i]), '<br>';
        }
    }
}

So to visualize what I'm doing imagine two arrays:

$lines = ["line1", "line2", "line3changed"] //textarea lines posted
$db_lines = ["line1", "line2", "line3"] 
//$db_lines = the current rows in lines db table
// line_number | row
// 0           | line1
// 1           | line2
// 2           | line3

//outputs 
//Added the line: line3changed
//Deleted the line: line3

So basically what I'm asking is, am I doing this the right way?

I would have over 10,000 lines that would be altered every hour in this table and am unsure if I'm doing it the correct way

<?php
echo <<<_END
<form action="form.php" method="post">
<textarea name="textdata" cols="50" rows="20"></textarea>
<input type="submit" name="submit" value="CLICK ME">
<input type="hidden" name="submit_check" value="1">

</form>
_END;
function write(){
$fname="test.txt";
$fh=fopen($fname,'w');
$data=$_POST['textdata'];
fwrite($fname,$data);
fclose($fh);
}


if(isset($_POST['submit_check'])){
write();
}
?>

Dear All Members

here is my table data..

(4 Columns/1row in mysql table)

id                 order_no               order_date                  miles
310                001                   02-15-2020                MI,108.53
                                                                                     Oh,194.57
                                                                                     PA,182.22
                                                                                     WA,238.57

How to split(miles) single column into (state, miles) two columns and output like following 5 columns /4rows in mysql using php code.

(5 Columns in mysql table)
------------------------------------------------------------------------------------

id                  order_no              order_date              state      miles

310                001                   02-15-2020               MI          108.53

310                001                   02-15-2020              Oh          194.57

310                001                   02-15-2020              PA          182.22

310                001                   02-15-2020             WA          238.57
 

------------------my php code -----------

<?php
//invoice.php  
include('../includes/config.php');

if(isset($_POST["add"]))
{
$order_no=$_GET['order_no'];
$order_date=$_GET['order_date'];
$miles=$_POST['miles'];

$miles = explode("\r\n", $_POST["miles"]);
$newdata = "'" . implode("','", $_POST["miles"]) . "'";
$sql ="INSERT INTO tble_states_miles(order_no,order_date, miles) VALUES(:order_no, :order_date, :newdata)";

$query = $dbh->prepare($sql);
$query-> bindParam(':order_no', $order_no, PDO::PARAM_STR);
$query-> bindParam(':order_date', $order_date, PDO::PARAM_STR);
$query-> bindParam(':miles', $newdata, PDO::PARAM_STR);

$lastInsertId = $dbh->lastInsertId();
if($lastInsertId)
{
echo "<script type='text/javascript'>alert('Added Sucessfull!');</script>";
echo "<script type='text/javascript'> document.location = 'ifta_miles_calculationlist_added.php'; </script>";
}
else 
{
$error="Something went wrong. Please try again";
}

if($query->execute()) {

$sql = "update tis_invoice set flag='1' where order_no=:order_no";
$query = $dbh->prepare($sql);
$query-> bindParam(':order_no', $order_no, PDO::PARAM_STR);

$query->execute();

}
}
?>

----------------- my form code ------------------

 <?php
                   $order_no=$_GET['order_no'];
        $sql = "SELECT * from tis_invoice where order_no = :order_no";
        $query = $dbh -> prepare($sql);
        $query->execute(
  array(
   ':order_no'       =>  $_GET["order_no"]
  )
 );
        $result = $query->fetchAll();
        foreach($result as $row)
?>
    
                    <form method="post">
                        <table align="center" style="width: 55%">
                        <tr><td>Invoice Number</td></tr>
                        <tr><td><input type="text" name="order_no" value="<?php echo $row["order_no"]; ?>" readonly=""></td></tr>
                        <tr><td>Invoice Date</td></tr>
                        <tr><td><input type="text" name="order_no" value="<?php echo $row["order_date"]; ?>" readonly=""></td></tr>
                        <tr><td>
                               <textarea name="miles" class="form-control" rows="10" placeholder="" required></textarea>
                           </td></tr>
                           <tr><td>
                         
                            <input type="submit" name="add" class="btn btn-primary" value="Add" />
                       </td></tr></table>
                    </form>

-- Can any one help how to correct my code..present nothing inserted on table

Thank You