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A PHP Data object or PDO is an extension that allows us to have a consistent way of interfacing with databases making our communication much easier from within our project. The first step in working with our data is to use a database specific PDO Driver.
If you are unable to trigger an Exception by just misspelling the database name, try changing it to look in a different location.
Such as:
$db = new PDO('sqlite:/database.db');
Notice the / instead of the ./ which is a very common error.
A PHP data object, or
0:00
PDO, is an extension that allows us to
have a consistent way of interfacing with
0:02
databases, making our communication much
easier from within our project.
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The first step in working with our data is
to use a database-specific PDO driver.
0:10
Before we create our PDO and
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connect to our database, we should do a
quick review of some object-oriented PHP.
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Since our PDO and all that it returns is
in OOP form, our object or
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our PDO PHP data object is an instant of
the PDO class.
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That object it will have its own variables
called properties, and
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its own built in functions or methods.
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To start with,
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we're gonna need to connect to our
database using a PDO database driver.
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We'll be using SQLite for
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the following example, so let's see what's
needed for that database.
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So we'll do that by opening up a tab, and
doing a search for PDO drivers.
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[SOUND] Okay, and the first one is the one
we want.
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And then we can see here we have several
different PDO drivers.
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You'll see it says database extensions
here at the top,
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abstraction layers and PDO.
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If you end up on just the PDO main page,
you can scroll down, and you'll see that
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the very bottom, or pretty close to the
bottom here, you'll see PDO drivers.
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So that's where we left off.
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So in PDO drivers, we're gonna want
SQLite, so we click SQLite.
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Let's see what it requires.
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Says PDO SQLite driver that implements the
PHP data objects interface,
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which we'll be working with, to enable
access to SQLite 3 databases.
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In order to do that, we're going to need a
certain string.
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Let's see here.
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We need a PDO DSN, okay?
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So we will need the data source name, or
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DSN, which is the prefix, which is going
to be SQLite.
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And we can see more info here, and to
access a database on disc,
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which is what we have, we would append the
absolute path to the DSN prefix.
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Okay, so taking all that in, let's go make
it work.
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Head back over to your workspaces.
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You can leave this open.
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I'm gonna go ahead and close it.
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And now, I'm gonna go ahead and bring my
console down.
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If it's still there, you can just tuck it
away.
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Or if you want, you can do Hide Console.
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I'm gonna open up my index.php file,
scroll to the very top, and
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here I'm gonna open up some standard PHP
tags, and
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we'll add our connection code to start
with, here in the index file.
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Go ahead and close it.
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And inside here, we're gonna wanna do a
couple of things.
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The very first thing that we're gonna
wanna do,
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is to enable our error reporting.
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And to do that, we're going to first add a
comment, and that comment is
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gonna remind us to get rid of this code
before we put it in production, because we
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don't wanna display errors to just any
user, it's just for development purposes.
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So I'm gonna say remove before flight.
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Okay, in the next line of code, we're
going to call a built-in PHP
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function called ini_set, so ini_set.
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And then in here, we're gonna have two
different strings.
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The first string is what we wanna set,
which is display_errors.
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And that is display_errors.
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And then we're gonna put another string,
which is what we wanted on or off.
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And in our case, we want it on.
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Close our line with a semicolon and that's
our very first step that we
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have error reporting or displaying errors
to our screen on.
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The next thing we're gonna do is create
our PDO object.
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We do that through object oriented code by
instantiating a new PDO object.
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So, first we give it a variable name to
store the object in, so
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$ and I'll go with DB for database.
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The next is the keyword new to create a
new object.
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And then our class, which is capital
P-D-O, and then open and
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close parenthesis and close our line.
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So inside of our PDO, the first thing that
happens is we need a DSN.
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And for us, if we recall, it was SQLite,
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followed by a colon, followed by the
absolute path of the database on disk.
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So, head back a couple, open up some
strings, and then we're gonna do sqlite:,
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in our case, it's in the same folder, so
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we're gonna do ./ and then database.db.
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Okay.
We're gonna save that,
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go down to the next line, and just to see
that we've created our new object,
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we're gonna do a var dump for the actual
DB object that we created.
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So let's do that now.
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Var_dump, open and close our parentheses,
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and then inside our object $db, close our
line with a semi colon, hit Save.
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I'm gonna go ahead and hit die after this.
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That will stop the actual rest of the file
from loading, hit Save and
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then click on our Preview icon.
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Okay, so here we are seeing it's dumping a
object.
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It is a PDO object.
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If we were maybe to, perhaps, make a
mistake, maybe a spelling error.
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So let's add a couple extra's As in here.
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Save our file, and then re-hit the icon.
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You might get this, which is a fatal
error, uncaught exception, and
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then PDO exception.
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Well, we don't want uncaught exceptions,
we don't want that accidentally happening,
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so the next thing for us to do is a little
bit of error handling.
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But before we do the error handling, let
me go ahead and fix my error.
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So I'm gonna go in close this and remove
some of these As.
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Save and then re-preview.
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All right, great.
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Now let's move on to some air handling.
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