Beginner PHP Tutorial - 160 - Protecting Email with String to Image Part 4 Video Lecture | PHP for Absolute Beginners: From Novice to PHP Master - Web Development

okay so I've opened up PHP my admin' so
we're going to be years of administering
our database let's have a look at what
we've already got stored now your
database could obviously be different
you could be using it for different
purposes mine is a basic login database
so this information that's stored about
users is going to help us log in now
that's irrelevant for now we've got an
ID of six for Alex and an ID of seven
for Dale now this is a unique
incrementing value so what we could now
do is modify our generate PHP file to
take in a user's ID and what that's
going to do is it's going to return
their email address as we have just by
typing it in here so let's just close
the source on here so the first thing we
need to do is connect to our database so
let's go ahead and just quickly connect
to our database we're going to say MySQL
connect now this is very rough so don't
follow my example in this sense and
there is another tutorial about
connecting to a database so root MySQL
select dB
so what we're doing now is we're
selecting the database which I believe
is called a underscore database so a
underscore database now let's perform a
query and this is going to be MySQL
query and we can say select email so
we're selecting the email field which is
here so select email from so what our
our tables called oops sorry our tables
called users so let's select email from
users
we're ID equals and we want to specify
the ID of the user and that's going to
be taken in let's copy and paste this up
here so query equals MySQL query select
now so that ID here is going to be we'll
just call this ID for now and what I'm
going to do is add some just some
security on to this so I'm going to
enclose this in my MySQL real escape
string to help prevent SQL injection
okay so if is set get and this time
we're going to get the value ID and
we're now going to say ID equals dollar
underscore get ID so now let's let me
briefly take you through what I've done
I've connected to the database using my
over connected to the server the MySQL
server using my credentials then I've
selected my database now I'm checking
for an ID input the idea is going to
equal the input that we've specified
using our get otherwise email is going
to say no email specified once again so
down here what we can do is perform our
query which we've performed now we
should retrieve some information back so
I'm going to say query result is equal
to MySQL result now we can specify the
query that we executed and we can also
specify the row which is going to be 0
because we're only going to retrieve one
row and then the field here so that's
going to be email so the query that we
performed here the row which is going to
be the 0 row which is the only row
that's been returned and email there so
what we could do is have checks in here
to check if this exists so if the ID
exists I suppose we could quickly do
that now if MySQL num rows query is
greater than or equal to 1 which it will
never be great at the moment we can
include this check anyway this
comparator
anyway and do then get the result
otherwise email equals ID not found now
what I'm going to do is I'm going to
change the change the name of this query
here this variable here I mean to email
because the value that we're returning
from this MySQL a result function is
going to be the email address of the
user
therefore now what's going to happen is
our script is going to run as normal so
let's go through this again just so you
make sure you entirely understand we're
connecting to our database or connecting
to our server selecting our database
checking if this ID value which we
previously had let's go back to our
source we previously had as email equals
this will now read ID equals and then
we're going to specify a specific ID
then the ID variable here is equal to
what we've specified otherwise email
equals no more specified as we did
before now what we're doing is
performing a query in fact we're going
to perform this query here inside here
because otherwise there's no need to
continue and we'll change this to no IDs
specified so sorry if that's confused to
let's bring this down to make make it a
bit easier to read so if if we have set
this ID thing then we complete a query
so query is selecting email selecting
one field from the users table where our
ID equals the ID that we've specified so
i ID up here ID up there MySQL real
escape string for a bit of security
against SQL injection now we're checking
if the rows returned are bigger greater
than or equal to 1 so if they are
greater than equal to 1 which means that
we have successfully retrieved an email
value we retrieve this value by using
the MySQL result function now query that
we've run up here 0 row which is the
only road that's been returned and we're
retrieving the email field otherwise
email equals ID not found then we come
down here
and we do our checks as I've already
explained in the tutorial so let's test
this out after that long mouthful of
explaining let's go back to index dot
PHP let's first of all not specify and
see if we returned with the correct
error you'll see no ID specified so now
let's go in and say ID equals now the ID
that we have in the database the two IDs
we have six and seven so let's specify
this to 10 because that doesn't exist so
he should when we refresh our page
retrieve the result saying that we the
idea is not being found
so ID not found so that's fine it works
now let's go back and do it sensibly so
we can say six now what this should now
do is retrieve the email address of user
6 and that is Alex at some domain comm
so let's go over to our page and refresh
and we retrieve Alex at some domain.com
so not only we're converting this to
text we're securely doing it because now
if we look at our page source the email
address doesn't exist anywhere in this
code okay so our bots are going to find
it harder to pick up a plain text email
value so let's just try it with seven
which is Dale's email address and then
the tutorial will be over so let's
refresh and you can see that's changed
to Dale at some domain.com
so that's a little bit about why you
should use this method as much as
possible and a really quick and easy way
to do it play around with a code make it
your own change colors change font sizes
and I wish you the best of luck with
creating this and because our functions
do get a bit tricky