Git Tutorial - 16 - Getting Old Versions from the Repository Video Lecture | Version Control with Git - IT & Software

alright guys welcome back to another
video and in this tutorial probably one
of the most useful tutorials up to this
point because I'm going to show you guys
how to get old versions of your project
from the repository now of course you
want to do this whenever you actually
committed some changes and maybe your
boss decides that you know well we
didn't want those changes or maybe you
decide that you want to go back to older
version because the new changes has some
bugs in it or something like that
so before I show you guys how to do this
I want to explain exactly how it's going
to be done and how it might be different
than you think so
this what I'm about to type it isn't
actually any github code this is just a
me demonstrating so we'll say that this
was our first commit this was our second
commit and then this was our third one
so the first one just the initial commit
was fine the second one we made some
improvements pretty cool pretty cool the
third one we hired some dude and he lied
on his resume he actually wasn't the
greatest programmer ever and he
committed a bunch of stuff that pretty
much ruined our project so now we're
like okay we need to revert back to the
second one right here so what you may be
thinking is this just go ahead and
delete that delete the third commit
somehow and we're at our second one but
that's actually not what we want to do
and github org sees me and get and the
reason for this is because what these
commits pretty much represent our points
in time points in time that we want to
be able to access if we ever need to now
you never want to delete any point in
time because that's the point of get
going back to a certain point of time
and your project if you ever want to so
how do we get that second one without
deleting the third well what we actually
are going to do is pretty much get a
copy of the second one and revert back
to it so our project flow pretty much
looks like this first second version of
the website third version of the website
actually instead of just deleting it and
going back the second we're going to
revert back in a linear fashion so
that's the process
and that's how it's going to go down and
now not only do we got the second
version the good one but we can go back
to third if we ever decide for some
reason that we want to do that
pretty freakin cool so let's go ahead
and do that right now so if we look get
log I already made that first commit the
first initial commit pretty much the
basic website so now let's actually make
some improvement to it um we'll say that
we need another icon for the forum so I
don't know these really look like a
forum but we can use this profile one
for now so copy this profile and we'll
say we'll just put it at the end all
right so this will be a link to the
forum that's not how you spell forum and
of course it's linking to forum HTML and
let's also give a color what color do we
want to give it give this blue color in
that blue color actually one of my
favorite colors zero zero six six nine
nine all right now check this out so now
we got a nice little icon link to the
forum that's good ready to commit it so
let me just do a hard commit right here
so get commit a.m. and I'll put on
something like made a icon for the forum
now go ahead and hit enter get status
we're good we made that commit so now
actually if we type git log we see the
first commit the second comment our
project is definitely looking better so
now I decide that you know I don't have
time to be making all these what the
heck is this really in the minimize to
toriel get the F out of here and another
pop-up oh that's probably great mate all
right
so now obviously I got to spend my time
fixing that Java error that just popped
up so what I'm going to do is actually
hire someone else to make some more
icons so we hire this dude named
Kevin because Kevin is a dummy and he
thinks he knows all about web design so
he's like okay I'm just copying this it
doesn't really matter what you copy just
like paste some of this crap and mom you
know maybe this is a link to um like
pornhub porn hub and this one you know I
just put to my personal page my name is
Kevin and suddenly I have an accent now
don't know why all right so save that
right there and then if I look at this
okay well I messed it up a good enough
let's just go ahead and commit that
anyways so what I'm going to do is go
ahead and commit this and what's cool
message put here my name is Kevin and I
am dumb okay good enough right there
alright so we obviously fired Kevin but
now look at this our project is all
messed up and what we want to do is we
actually want to go back to this commit
right here this one where we made a icon
for the forum that was the good version
of our project so how do we do that
well make sure that you type git log so
you can see pretty much a list of all
your commits right here and the first
thing that we need to do like I said is
get a copy of this now if you type this
get check out what that's going to do is
pretty much check out one of these
versions so what version or what commit
do we want well the second one right
here so how do we tell git use the
second one well you can't just type it
what we need to do is we need to
reference the commit number the commit
number this idea right here in yellow is
how it keeps track of the different
versions of your project so what we can
actually do is something like this look
at this 0 1 e 7 0 1 e 7 in DB a so what
we can do is we don't need to type out
this whole string of text we can just
type the first few characters and then
get is automatically going to know okay
that's the commit that you want a
reference so
we'll get check out - - index that HTML
all right I can't even type now so what
we're saying is go to this commit this
version of our project and get a copy of
index.html now hit enter and that's
exactly what it did so now if I look at
get status it says okay you have a
different version right here that's
different from the repository and that's
exactly what we want because this is the
good version that we just checked out so
now as you can see what it did is it
went and it got that good version the
version that we did that was the correct
one and it moved it into our working
copy pretty cool and now actually if we
refresh this page check it out we're
right back to where we want to be so the
only other thing we have to do here is
actually commit our changes because
they're good in our working copy right
now but they're aren't committed to the
main repository the repo is up-to-date
so if I just do git commit and I'll just
write something like undoing
Kevin's uh mistakes and hit enter get
status to verify we are good to go so
that my friends is how if you ever want
to and you're probably going to want to
do this a lot get old versions of your
project from the repository without
deleting any important points of time so
thank you guys for watching don't forget
subscribe and I will see you guys in the
next video