MongoDB Tutorial for Beginners 8 - MongoDB Update Document Video Lecture | The Complete Developers Guide to Mongo DB - Database Management

hello guys welcome to the next video on
MongoDB database tutorial for beginners
in this video we will see how we can
update our document using ODB so let's
get started first of all we are going to
switch to the same database as we have
used in the last video which is cool so
just write school use school and execute
it and now we are switched to school
database now first of all let's let's
list all the documents so we know what
our documents present so just write DB
dot student which is a collection dot
find and then give this brackets here
and executed and these are the documents
we have now to update our document what
we need to do is we will just write DB
then the collection name and then there
is a special method called update which
we can use to update document or
multiple documents ok so just give this
command and inside these round brackets
what we can do is we can give first of
all the condition on the basis of which
we want to add it for example we want to
add it the age or the surname of a
student whose ID is this one for example
right so in this condition our condition
is this one which is ID is this and
wherever the ID is equal to this ID then
we are going to change the surname right
so just give this curly brace
let's give two curly brace because we
are going to use both of them and in the
first curly brace we just need to give
your condition for example ID is equal
to this ID right so we will give this
and in the second
recive we will just give the value we
want to set right but this takes a
special parameter called
dollar set so this will tell or this
will tell the MongoDB to set this value
right and then give : and once again
curly brace and then the value which we
want to set so for example you want to
set the surname here right so let's set
this surname and instead of this name we
want some other surname for example some
other survey right and then just execute
this come on just select all this
command and execute it and you can see
one modified okay and once again we can
give DB dot students dot find and this
is not version but students and execute
it and you can see the surname is
changed here right so in this way you
can change or update your document the
second way to update a document for
example you want to update multiple
document based on some condition so how
to do it so we will add it the same
command or let's copy this command and
paste it once again here and this time
what we want to do is the student which
have the age 16 because we have two
students which have the age 16 for
example we want to change the surname of
these two student whose age is 16 this
and this one right so how we can do it
so instead of this condition ID we can
give the age condition now right so
instead of this just write age is equal
to 16 and
then set and then the last name we want
to set some surname right so for example
some song name and then once we execute
this command let's see what happens so
there are two data which must be
affected by this so let's execute this
and this time it says modified is equal
to one but we were expecting the - you
know values to be affected by our you
know command and the reason for this is
the update command when you you know
executed something like this is going to
just update the first document which it
finds satisfying this condition
so let's first fall list our you know
documents once again and let's see what
happened so in here you can see one of
the document which is first document
it's updated but the second document is
not updated right now to update the
multiple document we need to add one
more condition here and this condition
is the third condition and what is the
condition the condition is just give the
curly brace once again and then just
write multi coolin true and let's
execute this command but I'm going to
remove this and don't forget you need to
give the comma here right and then once
again execute this command and it says
one more data is affected which is the
other data right so just list out the
documents once again and once again this
other document is you know corrected or
edited or updated right now once again
we will try to update with this come on
and this time it should
you know update the multiple data so
let's update the surname once again some
weird surname and then once again
executed and it says modified - that
means it modified two commands and let's
list out our data once again and you can
see at the two places
it has modified the documents now there
is one more command which can be used to
update the data and this command is the
save command so how it works so instead
of using these commands what we do is we
will just write DB dot student which is
our collection name dot save and in this
save command what we can do is we can
give the whole JSON which we want to
update so this command do two things if
the ID so for example we can we want to
edit this data we can just copy the
whole Chasen and we can paste it here
and for example we want to change the
age here we can just change the age to
for example 14 okay so what it does is
its search for this ID inside your
documents and if this ID is present then
it's going to you know set the data or
update the data for this ID document or
otherwise if this ID is not found it's
going to create a new document with the
new ID and the new data right so let's
execute this command and let's see what
happens and it says one document
modified and let's list out our
documents once again and you can see the
age is changed now let's change the ID a
little bit so for example instead of
we have until 9 e so let's give 9f okay
and the student name is Tom for example
and some surname and the age is for
example 16 or let's say 17 okay and
let's remove this command and let's
execute this command and you can see
right result so once again we can list
out all the documents and you can see a
new data is added to your documents
which is this one right so this works in
two ways one for inserting the data and
other for updating the data so in this
way you can update documents in MongoDB
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