Tutorial 16 - UPDATE AND DELETE IN TABLE Video Lecture | Postgresql: A Complete Tutorial - Database Management

otherwise welcome to our tutorial of
PostgreSQL in this tutorial I will tell
you how to alter and how to delete our
records in the table so first of all we
should check all our records that is
from a company level that a select star
from company so as you could see that we
have these many records available with
us so suppose now I want to change the
age of prion sheet that is having an ID
of 8 so here's where the importance of
primary key comes in that uniquely
identifies a zero now suppose if there
was no prior no primary key I would have
not known the column that would have
uniquely identified the name pre on C or
the age of PNC or where she belongs to
so this is the importance of primary key
that it uniquely identifies each and
every row in our table so now I could
identify pre on she as ID number 8 so
this is the primary key of a table if
you remember so I would be using this to
alter each and every value that is
related to pre on C now so we would do
that by update queries that is update
company set age equals to 24 where ID
equals to 8
now you could run this query and you see
that it runs successfully now if I do a
select on the status select star from
company you will see that the age of pre
on she has been turned out to be 20 34
or has been turned out to be 24 now so
you could see this it was 23 and now it
is 24 so you could use any query you
could build up complex queries to select
results or change values so this was how
to alter the values in our table so you
could do it straight away by the PG
admin now you have a primary key you
could just click on the company table
and you could open this the view the
graphical view and you could just change
it straight
from here you could just make it 25 now
and this would do a straight away
without any query so this is the direct
method so the next thing that we are
going to talk talk about is how to
delete a record from a table so the
answer is pretty simple that we are
going to delete it by the primary key
itself that uniquely identifies it so
you would just use the delete command
that is delete from company where ID
equal to 8 so that would simply delete
the ID number 8 that is you would select
star from Campina and you would see that
the called number 8 our pre an she has
gone you could see that it is not no
more there so the simple way to do that
is again open up the graphical view and
on a record just right click and delete
and you would see that it has gone so
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