MySQL Database Tutorial - 8 - Sorting Results Video Lecture | MySQL (Sequential Query Language) Database Tutorial - Software Development

what is going on guys welcome to your
eighth MySQL tutorial and in this lesson
I want to start off by talking about
fully qualified names now let me go
ahead and show you guys what the heck
I'm talking about select address from
customers I'll go ahead and show you
guys the variation that we've been doing
and then I'll show you guys how to make
fully qualified names so if you go ahead
and run this query we can see that it
selects all the addresses from the
customers in our table simple enough so
what is a fully qualified name a fully
qualified name would be something like
this select customers address from
customers we go ahead and run this query
it gives the exact same thing so
basically am i saying that there is two
different forms of writing the same
query two different variations of the
same syntax well yes that's exactly what
I'm saying
so why is this the case why would they
make - glow to basically be we can give
it two different instructions in the
exact same way so first of all whenever
you're working in a class and you have a
really strict teacher they may make you
write the fully qualified name so just
to you know make your life more
miserable or a more useful way that you
could you would write fully qualified
names is say you are making a huge
website and you had something like eBay
where you add buyers and sellers now
buyers and sellers both have addresses
so you may want to write ok buyers
address sellers address and then quickly
just by looking at your code you can
determine what table you're working with
so whenever you have a lot of tables and
you have the same a column in multiple
tables it may be useful so that is you
know a different way when you would want
to use fully qualified names but for the
rest of these tutorials I'm just gonna
be using the I don't know what they're
called fully unqualified names I guess I
don't know I just made that up don't
quote me but now that we understand
fully qualified names basically it
doesn't you know matter performance wise
it's just you know okay I'm just gonna
move on because enough with fully
qualified names they're boring
well isn't boring though is learning how
to sort our results so
let me go ahead and run a simple query
like select a name from customers go
ahead and hit and go and look at our
results
Bucky Noah Kelsey Corey Harry okay
that's nice but our boss is gonna come
in he's gonna be Ike dude Bucky these
names are way too randomized I want this
in alphabetical order and we're like oh
crap how the heck do we do that but
lucky for you you've been watching my
tutorials and you know that if you add
the keyword order by and then you go
ahead and write the criteria you want to
order your results by you can go ahead
and hit go and check it out whenever we
hit order by name it takes the results
in orders by the name now whenever we're
ordering um like letters it's gonna
order alphabetically and whenever we're
ordering numbers it's gonna order that
what's it called alphabetically but by
number I guess I don't know how to say
that numerically there we go BAM baby so
by default it orders it from A to Z and
we can change that later on I'll show
you guys how to order in reverse
alphabetical order or later on but now I
want to mention this because now that we
know how to order results you may be
thinking okay what if I wanted to
retrieve some information for example I
want to retrieve the name and address
from customers but I want it to order by
the ID number can I do this even though
the ID number isn't retrieved well yes
you can this is perfectly legal results
can be sorted by their ID even though we
don't want the ID to be retrieved so let
me go and check it out as you can see in
our results that we get Noah or excuse
me Bucky Noah
Kelsey Cory Harry and at first this may
look unsorted totally but if we browsed
the entire customer staple check out the
IDS Bucky Noah
Kelsey Corey Harry so this information
is sorted blur by their ID number even
though the ID number was not retrieved
now I want to mention this
another thing that people get confused a
lot about is whenever they want to sort
multiple columns now we already learn
how to retrieve multiple columns for
example we can retrieve the ID name and
address of you know a table but what if
we wanted to do something like this we
wanted to retrieve multiple columns well
let me just go ahead and show you guys
an example because if I talk try to
explain it without showing you guys an
example it's gonna get kind of confusing
so I just show you guys the example
first select state city and name so this
is the information we want from
customers and we want to order by state
in name so let me go ahead and run this
in check it out well I'm trying to say
is this at first the first criteria we
give it to order by a state and so it
takes in orders the states
alphabetically Arkansas Alabama I don't
know what these I'm not very good it's
like Alabama I think California I know
that one but check it out even though
all these states are sorted
alphabetically look what happens
whenever we have one two three four five
six California's so it's gonna say okay
I order the states but how do you want
me to order all of the people that are
in California well whenever we have
multiple states we say okay now that
you've done that now the next criteria
to sort by is the name of the people so
says okay first I sorted by state and
then within those states I'm gonna order
the people in that state based on you
know of course alphabetical order so
basically states are arranged in order
and then each person in that state are
arranged alphabetically and we did this
by giving it more than one order
criteria first order by state and then
order by name so again the rule for this
is the same is whenever we're selecting
multiple columns one less comma then
column name so just remember that and
you'll be good to go so anyways that is
how you retrieve multiple columns and
order my multiple columns so okay
probably brain overload right now so I'm
gonna let you guys take a break go get a
glass of chocolate milk come back and
watch the next video but for now thank
you guys for watching and we're gonna
subscribe and yeah I'll see you next
time and don't forget if you have any
questions just ask me I'm reformed