sending email for birthday don't show emails - php

Question

I have issue with email in my table when I try to send mails for birthdays..
Here is the printscreen, if you see the table in the right, there are 2 users with birthdays but in the input below of div error is empty... and say "there is not birthday for today":
<?php
$sql = $conn->prepare("SELECT email FROM USERS WHERE f_nac >= CURDATE() AND f_nac < CURDATE() + INTERVAL 1 DAY ORDER BY f_nac ASC");
$sql->execute();
while($row = $sql->fetch(PDO::FETCH_ASSOC)) {
$email = ($row['email'].", ");
}
$largo=strlen($email);
if ($largo>2)
$email=substr($email,0,$largo-2);
} else {
echo '<div class="alert alert-danger">No hay cumpleañeros!</div>';
};
?>
<input type="text" id="email" name="email" value="<?php echo $email; ?>" />
How can I show the emails to send the mail to them?
the two users have emails and the row in the table is "f_nac" with type "date"

Answer 1

CUR_DATE() is in 2014, the birthdays are in 1975 and 1978. You have to ignore the year when you're comparing.
SELECT email
FROM USERS
WHERE MONTH(f_nac) = MONTH(NOW()) AND DAY(f_nac) = DAY(NOW())
In your while loop you're overwriting $email, not appending to it. It should be:
$email = '';
while ($row = $sql->fetch(PDO::FETCH_ASSOC)) {
$email .= ($row['email'].", ");
}

Answer 2

What you are doing currently is extracting the data from SQL (daily) and composing and email to send the wish manually daily. What if I suggest you a better approach ?
There is an application called Wishing Application which can send birthday and work anniversary mailer with a breeze.
At minimal it just need two things excel file with wish details (Date, name, email) and a configuration file (application.properties) and that is it, you are good to go.
Further there various options to run the application locally (Command line, foreground, background, docker, windows scheduler, unix cron etc) Cloud.
Application is highly configurable , you can configure various details like:
Workbook loading options
Image options to send with wishes.
SMTP Configurations
Other application level configurations like, when to send wish, belated wish, logging etc.
Disclaimer : I am the owner of the application