Export MySQL database to CSV while converting Unix to date - php

Question

A little bit of backstory first. I have a database that works with a custom created ticket system. New tickets are input via a HTML form that uses PHP.
I need to be able to export certain results to a CSV depending on what the users selects on a separate form.
A quick google of MySQL to CSV with PHP brings this website up.
http://www.a2zwebhelp.com/export-data-to-csv.
I've amended the code slightly so that the query doesn't select all columns from my table, below is my amended code.
<?php
// Database Connection
$host="localhost";
$uname="REMOVED";
$pass="REMOVED";
$database = "REMOVED";
$connection=mysql_connect($host,$uname,$pass);
echo mysql_error();
//or die("Database Connection Failed");
$selectdb=mysql_select_db($database) or die("Database could not be selected");
$result=mysql_select_db($database)
or die("database cannot be selected <br>");
// Fetch Record from Database
$output = "";
$table = "site_calls"; // Enter Your Table Name
$sql = mysql_query("select call_id, call_first_name, call_email, call_department, call_subject, call_status, call_user, call_date, call_date2 from $table WHERE (call_user = 15)");
$columns_total = mysql_num_fields($sql);
// Get The Field Name
$columns = ["call_id","call_first_name","call_email","call_department","call_subject","call_status","call_user","call_date","call_date2"];
for ($i = 0; $i < $columns_total; $i++) {
$heading = mysql_field_name($sql, $i);
$output .= '"'.$heading.'",';
}
$output .="\n";
// Get Records from the table
while ($row = mysql_fetch_array($sql)) {
for ($i = 0; $i < $columns_total; $i++) {
$output .='"'.$row["$i"].'",';
}
$output .="\n";
}
// Download the file
$filename = "TicketExport.csv";
header('Content-type: application/csv');
header('Content-Disposition: attachment; filename='.$filename);
echo $output;
exit;
?>
This almost does exactly what I want it to do. The only problem, is due to the way time/date is saved in the database (Unix) the output of 2 columns call_date and call_date2 are output as Unix. I need these to come out as DD/MM/YY or another human readable format. I can manually change this using a formula in excel, but this is something that a customer would have access to, and they'll need to be able to read the date.
Also, mysql is depreciated, are there significant changes to the above code to get it working on mysqli. The rest of the system is written using mysqli for inputting the data.
TL:DR. Exporting some columns from a MYSQL database, need to convert 2 columns from Unix to readable date/time using php.

Answer 1

Try this :
while ($row = mysql_fetch_array($sql)) {
for ($i = 0; $i < $columns_total; $i++) {
$heading = mysql_field_name($sql, $i);
if ($heading == 'call_date' || $heading == 'call_date2') {
$output .= '"'.date('d/m/y', strtotime($row["$i"])).'",';
}
else {
$output .='"'.$row["$i"].'",';
}
}
$output .="\n";
}

Answer 2

Use an if statement inside the for loop to identify you are on the date columns, then call the php date function to reformat.
Like this:
for ($i = 0; $i < $columns_total; $i++) {
if($i == 7 or $i == 8) {
$output .='"'.date('d/m/y', strtotime($row["$i"])).'",';
} else {
$output .='"'.$row["$i"].'",';
}
}
I hope this helps!