Send confirmation mail to last inserted row - php

Question

I am trying to create a simple Support Request system which users can insert their email address in a form though jQuery - Ajax and PHP into MySQL database.
After that I need to send a Confirmation Email to the inserted email owner "
every time that a new request inserted into the database". I was thinking about using the Ajax call from database but I am not sure how to select
1- latest inserted row AND
2- Not selected rows to do this( there might be a situation to have two insert at exact same time then the
SELECT email FROM tbl-request ORDER BY id DESC LIMIT 1;
might return Only the last inserted however there where at least two new entries)?
can you please let me know if there is solution to do this through MySQL Trigger or jQuery Ajax

Answer 1

suffii you can add a new colum to the table eg. status which contain 0 as a default value.
Now every time you send a email then update this value to 1.
so you can select the rows for which an email is not sent yet like this..
SELECT email FROM tbl-request where status=0;
It will select only the latest entry containing status = 0.
There can be many way But as my point of view this also can be a better and simplest way

Answer 2

you can do this using cron job.
Run a cron job line every 5 mins and set a flag to check if mail is sent or not. after sending mail set the flag to 1.

Answer 3

We can easily save the last time we checked in a database or file. This method of doing it would allow you to have the emailer system separate from how the record is inserted, which is what I gather you want given that you're suggesting use of Triggers or AJAX to handle it. This method will work even without access to write the database from the PHP script.
At the end of the email script run:
$fh=#fopen('last-email','w');
if (!empty($fh)){
fwrite($fh,time());
fclose($fh);
}
At the start run
$last_email_time=file_get_contents('last-email');
Then add a timestamp field to your table; this will automatically append the time the record was last edited or added.
Then your query will be:
$last_time_as_sql_date=date('Y-m-d H:i:s', $last_email_time);
$query="SELECT email FROM tbl-request WHERE timestamp>'$last_time_as_sql_date' ORDER BY timestamp DESC LIMIT 1;"
How you actually run the script depends more on your implementation; if on a server back end you could run every 5 minutes using crontab -e
*/5 * * * * php /path/to/script.php

Answer 4

You could send the mail from PHP at the moment the request is inserted, but you may want to keep those processes separated.
To do so, an easy fix would be to add a field 'ConfirmationMailed' or something to indicate that that mail was sent. That way you can just query for requests that weren't emailed yet.
A little bit more flexible would be to create a separate table tblRequestCommunication in which you store the communications about the request.
That table could have:
Id (PK), Date, RequestId
Subject
Content
CommunicationType
The communication type could be an enum or a reference to a separate type table in which you store the types of communication to send. One of those types could be 'Automated confirmation message', and in the table you can even store the exact date time, subject and content of that message.
Now, in your query, all you have to do is search for requests without such a confirmation:
SELECT r.email
FROM
tbl-request r
WHERE NOT EXISTS
( SELECT 'x' FROM tblRequestCommunication c
WHERE c.RequestId = r.RequestId
AND c.CommunicationTypeId = 1 /* Automated confirmation */)
This structure will allow you to expand this system for other types as well, for instance an automated mail when the request was closed:
SELECT r.email
FROM
tbl-request r
WHERE
r.State = 'Closed'
AND NOT EXISTS
( SELECT 'x' FROM tblRequestCommunication c
WHERE c.RequestId = r.RequestId
AND c.CommunicationTypeId = 14 /* Close notification */)
Also, you can store 'manual' e-mails and phone reports that are linked to the request in the same table, so you've got a full history of communication.
So, it's a bit of work to create one or two extra tables and change the query, but the abilities of your system will be a lot larger.