Make calculations in csv with php - php

Question

First let me introduce myself:
Im 33. 'Living in the Netherlands and i'm a newbe if it comes to php :)
I have a csv file on my vps httpdocs\data\1day.csv . In this file there are two columns: datetime and value. The file looks like this:
"datetime","value",
"2016-01-02 10:50:01","1060.9",
"2016-01-02 10:45:01","1060.6",
I want to make a simple calculation to the file 1day.csv and save it to another csv file. Let's say the caluclation will be value * 5:
"datetime","value","value2",
"2016-01-02 10:50:01","1060.9","5304.5",
"2016-01-02 10:45:01","1060.9","5304.5",
The calculation needs to be done over the whole "value" column.
I want to do this with php and let a cronjob execute this script every x minutes.
Can anybody help me in the right direction?

Answer 1

I would maybe do it more simple. If you didn't know how many columns you could do the extra loops to get column names, but it does not look necessary.
$output = "datetime, value1, value2\n"; // Column names
while ($row = mysql_fetch_array($sql)) {
$output .='"' . $row[0] . '" ,';
$output .='"' . $row[1] . '" ,';
$output .='"' . ($row[1] * 5) . '"';
$output .="\n";
}

Answer 2

#riggsfolly
Ok. This is what i got so far:
// Database Connection
$host="localhost";
$uname="xxxxx";
$pass="xxxxx";
$database = "xxxxx";
$connection=mysql_connect($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 = "quotes"; // Enter Your Table Name
$sql = mysql_query("select datetime, value from $table where type = '5' order by datetime desc limit 333");
$columns_total = mysql_num_fields($sql);
// Get The Field Name
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";
}
// Save the file
$directory = "/var/www/vhosts/domain.nl/httpdocs/data/";
$filename = "1day.csv";
$fd = fopen ("$directory" . $filename, "w");
fputs($fd, $output);
fclose($fd);
exit;
The part where i get stuck is to add the extra column with the calculated value.