How to export data from MySQL to CSV? - php

Question

I am trying to export data from MySQL to CSV using PHP from a website. When a user clicks generate the report it will automatically create and this will be downloaded as a file on their computer. The code below I have been following an online tutorial but I have run into some issues. Currently, it will download but will only show one row with one date value from the MySQL data.
I was wondering what I need to do to show all the data in the csv file and how do I ensure that the names of the Rows are printed as well.
#header("Content-Disposition: attachment; filename=record.csv");
$select = "SELECT * FROM DBtable WHERE user_id=$id";
$result2 = $conn->query($select);
while ($row = $result2->fetch_assoc()) {
$data = $row['pain']."\n";
$data = $row['sleep']."\n";
$data = $row['mood']."\n";
$data = $row['heartrate']."\n";
$data = $row['time_of_entry']."\n";
}
echo $data;
exit();

Answer 1

Instead of setting the $row values to $data, you should echo instead
#header("Content-Disposition: attachment; filename=record.csv");
$select = "SELECT * FROM DBtable WHERE user_id=$id";
$result2=$conn->query($select);
while($row=$result2->fetch_assoc()){
echo $row['pain']."\n";
echo $row['sleep']."\n";
echo $row['mood']."\n";
echo $row['heartrate']."\n";
echo $row['time_of_entry']."\n";
}
exit();
Your code just keeps setting $data to a rows value, without actually doing anything with it. Each line overwrites the previous, so when you do echo $data, you are echoing the last value it was set to which in your case was the last loops "time of entry" value.
As for adding "names of the Rows", currently the code puts in a value then a new line. You probably want to replace "\n" with ",", so one loops data is one one line, then before the closing while loop, echo a "\n" to insert a new line character. You can then put the titles in the same way, using an echo, and comma seperated titles, followed by a new line character.
For example
echo $row['pain'].",";
echo $row['sleep'].",";
echo $row['mood'].",";
echo $row['heartrate'].",";
echo $row['time_of_entry'].",";
echo "\n";