PHP export MySQL to csv for app inventor - php

Question

When I try to export MySQL table to csv (use php) and make it a list in app inventor, but the list doesn't show.
My Block :
My php file :
if ($result = mysqli_query($dbc, "SHOW COLOMNS FROM Absent")){
$numberOfRows = mysqli_num_rows($result);
}
if($numberOfRows > 0) {
$values = mysqli_query($dbc, "SELECT full_name FROM Absent");
while($rowr = mysqli_fetch_row($values)){
for($j=0; $j<$numberOfRows; $j++) {
$csv_output .=$rowr [$j]. " ,";
}
$csv_output .= "\n";
}
}
print $csv_output;
exit;

Answer 1

Try to export to csv using mysql native method, for example:
SELECT id, name, email INTO OUTFILE '/tmp/result.csv'
FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"'
ESCAPED BY ‘\\’
LINES TERMINATED BY '\n'
FROM users WHERE 1

Answer 2

i don't know much about app-inventor, but as for the sql queries:
the first table is "CUSTOMER", your second is: "Absent", is it a typo?
(your'e iterating your "Absent" row with the number of columns you're getting from "CUSTOMER", was that your intention?)
your "$rowr" var has only 1 column ("full_name"), so you could easily:
drop the "for loop", to:
$csv_output .=$rowr [0];
P.S.
an alternative way of coding that in php would be:
$result = mysqli_query($dbc, "SELECT column1, column2, column3 FROM Absent");
while ($row = mysqli_fetch_assoc($result))
{
$comma = "";
foreach( $row as $key=>$value )
{
$csv_output .= $comma . $value;
$comma = ", ";
}
$csv_output .= "\n";
}
print $csv_output;
exit;