MongoDB Tutorial for Beginners 7 - Query Document - AND OR Conditions 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 the last video we have seen how we
can query our documents in MongoDB on
the basis of some conditions for example
greater than or less than or equal to or
not equal to or how we can find the
first element which was inserted into
the database right now in this video we
will see how we can query the documents
on the basis of and/or or condition ok
so let's get started for example I will
use the same example as in the last
video we have this school database in
which we have the collection called
students and we have some documents
inside this collection right now for
example we want to you know very a
document or we want to fetch the data
whose you know student name is for
example first name is mark and age is 10
so this is and condition to condition
which are added together using and
operator right so we can just write DB
dot student dot find as we always do to
query the database and then inside these
round brackets just give these curly
braces and as the last time we just need
to give the same condition for example
first name is equal to mark which is
this one and when you separate this
condition by comma it means you are
using and operator right so first name
should be mark and age should be for
example 10 ok this means we want to you
know fetch the student whose first name
is Mark and his name or his age is 10
here okay so let's execute this and it
gives the first result
so this is how an operator works in
MongoDB now let's see how we can use our
operator in querying our document so for
example we want to query a document for
students whose first name is Mark or the
age is 15 so how we can do it so we can
once again write DB dot students dot
find and in these round bracket first of
all add curly brace like this and inside
this curly brace for using or operator
we use a dollar symbol and then write or
which says we want to use or operator
and then give a colon and then give a
square bracket here so just it's like an
array we want to query and then inside
this square bracket we have the number
of condition for example this curly
braces and once again curly braces and
then this curly braces comes your
condition and you can use and as many
you know condition as you want not even
two but multiple right so our first
condition is the first name should be a
mark and the age should be 15 okay so
what this means we want to query a
database of students whose first name is
mark or we are using our operator here
or the age is 50 okay so let's execute
this query and you can see we have two
result first is satisfying our first
condition which is this one and second
is satisfying the second condition which
is age should be 15 for example let's
say it should be 16 we have two student
whose age is 16 and let's execute this
and you can see we have
this data okay now let's see how we can
mix and an or operator for querying the
document so let's copy this command
again and paste it here and for example
first of all we want to you know query
data whose first name is mark once again
so we can just give this query first
like this and then just write comma and
then just give dollar or as we have done
here and then colon and then your other
condition something like this okay for
example you want the data whose first
name is mark or the age should be for
example 15 or the age should be 16 so
this condition and this condition is
separated by and and these two
conditions are separated by all okay so
once again execute the command and it
gives us nothing because there is no
student in our database whose name is
mark as well as whose age is 15 or 16
okay so let's change the condition for
example we want to have the data of
student whose age is 10 or 16 or and the
name is mark okay and once again execute
it and we have one data like this okay
so in this way you can use and and or
operator for querying
your documents I hope you've enjoyed
this video please rate comment subscribe
and bye for now