Remove occurances of ",,," from MySQL Database Output PHP - php

Question

I am outputting the contents of my MySQL Database into a text file using the below code:
<?php
$host = 'localhost';
$user = 'myusername';
$pass = 'mypassword';
$db = 'mydbname';
$table = 'mytablename';
$file = 'outputfilename';
$link = mysql_connect($host, $user, $pass) or die("Can not connect." . mysql_error());
mysql_select_db($db) or die("Can not connect.");
$result = mysql_query("SHOW COLUMNS FROM ".$table."");
$i = 0;
if (mysql_num_rows($result) > 0) {
while ($row = mysql_fetch_assoc($result)) {
//$csv_output .= $row['Field']."; ";
$i++;
}
}
$csv_output .= "\n";
$values = mysql_query("SELECT * FROM ".$table."");
while ($rowr = mysql_fetch_row($values)) {
for ($j=0;$j<$i;$j++) {
$csv_output .= $rowr[$j].",";
}
$csv_output .= "\n";
}
//echo $csv_output;
$myFile = "output.txt";
$fh = fopen($myFile, 'w') or die("can't open file");
$stringData = $csv_output;
fwrite($fh, $stringData);
fclose($fh);
exit;
?>
However I would like to know how I could replace the occurances of the string ",,," with this: "," before it goes into the text file.

Answer 1

No need for preg_replace().
A simple str_replace will suffice.
$stringData = str_replace(',,,', ',', $csv_output);

Answer 2

problem is in:
$values = mysql_query("SELECT * FROM ".$table."");
if you got ,,,, it means that some columns has no value. Detect those columns, do not include them in SELECT statement.
if you will automatically (preg_replace, str_replace) change multiple commas to one comma, you are on good way to corrupt CSV file.

Answer 3

Use preg_replace(). Something like this (untested):
$pattern = '/\,\,\,/';
$replacement = ',';
echo preg_replace($pattern, $replacement, $stringData);

Answer 4

add this code:
while ($csv_output=str_replace(',,', ',', $csv_output)) echo '.';
OR change the for code:
for ( $j=0; $j<$i; $j++) {
$csv_output .= (isset($rowr[$j])) ? $rowr[$j]."," : '';
}

Answer 5

str_replace()
$stringData = str_replace(',,,', ',', $stringData);
http://php.net/str-replace