Query database then email posts from where user is subbed to - php

Question

So I have a subscriptions table, here's the schema
+-------------+------------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------------+------------------+------+-----+---------+----------------+
| id | int(11) unsigned | NO | PRI | NULL | auto_increment |
| user_id | int(11) | YES | | NULL | |
| sub_to | int(11) | YES | | NULL | |
| date_subbed | varchar(255) | YES | | NULL | |
+-------------+------------------+------+-----+---------+----------------+
Pretty basic, here's an example row
+----+---------+--------+------------------------+
| id | user_id | sub_to | date_subbed |
+----+---------+--------+------------------------+
| 23 | 13 | 2 | 08/19/2014 07:44:49 pm |
+----+---------+--------+------------------------+
All pretty basic stuff. So user 13 is essentially subbed to user 2. So lets say that another user joins the site and another row is created with user 14 subs to user 5.
And now user 2 and user 5 post a message on the site and it gets inserted into the database. I want the users who are subscribed to someone to get an email with the newest post.
//Get user subs
$stmt = $con->prepare("SELECT * FROM subscription");
$stmt->execute();
foreach ($stmt->fetchAll(PDO::FETCH_ASSOC) as $key) {
print_r($key);
}
I've already tried a foreach loop but I couldn't see how it would work. So to sum things up I want to email the user when their is a new post. I'll be sending out an email every 24 hours so I don't kill the server. I want to make sure it's fully automated too. I know how to do the 24 hour time thing, but when I say automated I mean that it'll query and email by its self. Any pointers or ideas?

Answer 1

I figured it out. Just use ob_start(), and loop through each user. Select the posts they're subscribed to. Then inside the loop email it to each user. I used this query
SELECT
articles.*
FROM
articles
INNER JOIN subscriptions ON articles.from_id = subscriptions.sub_to
INNER JOIN users ON subscriptions.user_id = users.id
WHERE
users.email = :email

Answer 2

http://sqlfiddle.com/#!2/a1ceb/9
I kindof tried to do what your saying with SQL fiddle, but in trying it out it seemed impossible with the current schema. In the link above I have many comments about how you should completely redesign your schema. The query is a pretty big headache and not scalable unless you set up a new schema.

Answer 3

$sql="select email id from subscription";
$rs=mysql_query($sql); //resultset
if(mysql_num_rows($rs)>0) //checking whether anyone subscribed the user or not
{
while($d=mysql_fetch_array($rs))
{
$sql1="select * from subscription where sub_to in ('".$d["user_id"]."')";
$rs1=mysql_query($sql1);
while($ds=mysql_fetch_array($rs1)
{
$to=$ds["email_id"];//assuming the field for email id
$subject="";
$msg="";
#mail($to,$subject,$msg);
}
}
}

Answer 4

$sql="select email id from subscription";
$rs=mysql_query($sql); //resultset
if(mysql_num_rows($rs)>0) //checking whether anyone subscribed the user or not
{
while($d=mysql_fetch_array($rs))
{
$sql1="select email id from subscription where sub_to in('".$d["user_id"]."')";
$rs1=mysql_query($sql1);
while($ds=mysql_fetch_array($rs1))
{
$to=$ds["email_id"];//assuming the field for email id
$subject="";
$msg="";
#mail($to,$subject,$msg);
}//inner while end
}//outer while end
}