In essence, you can't output the CSV file and the link to it in one go. (You need to introduce the concept of a page "mode" and activate the download mode via a ...pagename.php?mode=download or similar. You could then use PHP's switch statement to switch on $_GET['mode'] in your script.)

That said, the text/csv content type header you were using is correct, although you may need also want to output the Content-Length and Content-Disposition headers. After you've output the file data, also be sure to stop any additional script processing via PHP's exit function.

Additionally, it would probably be a lot less hassle (and will certainly be faster/more memory efficient) to use MySQL SELECT ... INTO OUTFILE facility (if you have the permissions) rather than use PHP to gather the data.

In essence, you can't output the CSV file and the link to it in one go. (You need to introduce the concept of a page "mode" and activate the download mode via a ...pagename.php?mode=download or similar. You could then use PHP's switch statement to switch on $_GET['mode'] in your script.)

That said, the text/csv content type header you were using is correct, although you may also want to output the Content-Length and Content-Disposition headers. After you've output the file data, also be sure to stop any additional script processing via PHP's exit function.

Additionally, it would probably be a lot less hassle (and will certainly be faster/more memory efficient) to use MySQL SELECT ... INTO OUTFILE facility (if you have the permissions) rather than use PHP to gather the data.

In essence, you can't output the CSV file and the link to it in one go. (You need to introduce the concept of a page "mode" and activate the download mode via a ...pagename.php?mode=download or similar. You could then use PHP's switch statement to switch on $_GET['mode'] in your script.)

That said, the text/csv content type header you were using is correct, although you may need also want to output the Content-Length and Content-Disposition headers.

Additionally, it would probably be a lot less hassle (and will certainly be faster/more memory efficient) to use MySQL SELECT ... INTO OUTFILE facility (if you have the permissions) rather than use PHP to gather the data.

In essence, you can't output the CSV file and the link to it in one go. (You need to introduce the concept of a page "mode" and activate the download mode via a ...pagename.php?mode=download or similar. You could then use PHP's switch statement to switch on $_GET['mode'] in your script.)

That said, the text/csv content type header you were using is correct, although you may need also want to output the Content-Length and Content-Disposition headers. After you've output the file data, also be sure to stop any additional script processing via PHP's exit function.

Additionally, it would probably be a lot less hassle (and will certainly be faster/more memory efficient) to use MySQL SELECT ... INTO OUTFILE facility (if you have the permissions) rather than use PHP to gather the data.