Tutorial 19 - ORDER BY Clause Video Lecture | Postgresql: A Complete Tutorial - Database Management

hello guys welcome to our tutorial of
PostgreSQL in this tutorial I'm going to
talk about the order by operator so
order by operator is basically used to
sort our data in our database so if you
consider an example of a social
networking website or social networking
application you need to sort the data
like you want the recent data first and
then you want to show the older data so
for this we will use the order by
operator that is used to sort our data
according to a column so for example I
want to sort my data first of all
according to the salary of the employees
here like I want the least salary to be
first and then I want sorry to be
increased and I want to sort by rate
according to the salary so I will use
the order by operator that is select
star from company order by salary so
when you run this query you would see
that it is already ordered by salary so
like suppose I want to order it by age
now like I want the least age to be
displayed first then I want the maximum
age so just order it by a salary or
sorry ordered by age and you will see
that the least age is displayed first
and the maximum mate is displayed at the
last so by default this has a setting of
ascending order like it will display the
least result first or this is the ASC
that is ascending order if you run the
same it will run again and ASC is
ascending order that is the default
setting of the order by clause if you
want order to win in the descending
order you could just write be ESC and it
would sort your results into descending
order you will see that now this has
been sorted in descending order as you
can see so this is the use of order by
clause now another aspect of order by
Clause is clashes now suppose I have
salary I have age of 34 here and now I
have age of 34 with three fields three
fields of age of 34 now what happens if
the values are clashing of a particular
record so you could order by multiple
like equal to
use order by H and then salary so this
would mean that it would order by H
means it would order by age in ascending
order because it is already the default
setting is ascending and it would order
the salary in descending order like you
will see it with order our record in by
age first of all so it will show me I
will show you it will show you the least
age first of all that is ASC so it will
show me the least age first of all and
now I have clash in 34 34 and 34 and the
clash will be sorted by the salary that
will be in descending order you will see
that the maximum salary would two
salaries do not exist here um you could
see it okay I need to add this first of
all so you could just add one record to
show this that is you could see but add
8000 and you could add 4000 again now
you would see it
see that age with 34 is the maximum sari
displayed first
and following the minimum salaries so
this is the basic concept of the order
by clause if you want the age to be
displayed in descending order you would
just write ves see here again and you
would see that it is displaying the
order by in the descending order first
of all and now here it is a clash so it
should decide the clash by the maximum
sorry first followed by this so thank
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