1. (10 points) Use the solarSystem collection, calculate the average mass and number of moons
for each type of planet
The one document pattern is given like this.
There are nine such documents like the pattern given below.
{"_id":{"$oid":"59a06674c8df9f3cd2ee7d51"},"name":"Sun","type":"Star","orderFromSun":{"$numberInt":"0"},"radius":{"value":{"$numberInt":"695700"},"units":"km"},"mass":{"value":{"$numberDouble":"1.9885e+30"},"units":"kg"},"sma":{"value":{"$numberInt":"0"},"units":"km"},"orbitalPeriod":{"value":{"$numberInt":"0"},"units":"years"},"eccentricity":{"$numberInt":"0"},"meanOrbitalVelocity":{"value":{"$numberInt":"0"},"units":"km/sec"},"rotationPeriod":{"value":{"$numberDouble":"25.449"},"units":"days"},"inclinationOfAxis":{"value":{"$numberDouble":"7.25"},"units":"degrees"},"meanTemperature":{"$numberInt":"5600"},"gravity":{"value":{"$numberInt":"274"},"units":"m/s^2"},"escapeVelocity":{"value":{"$numberDouble":"617.7"},"units":"km/sec"},"meanDensity":{"$numberDouble":"1.4"},"atmosphericComposition":"H2+He","numberOfMoons":{"$numberInt":"0"},"hasRings":false,"hasMagneticField":true}
For the above question can you please help me write the mongodb query using aggregate,group
and unwind.
I have assignment due tom. When I asked the chegg team few hours the same question they
have used $size must be an array. Please give me the correct query..
Major project report on Tata Motors and its marketing strategies
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1- A movie may have many actors- and an actor can act in many movies-.pdf
1. 1. A movie may have many actors, and an actor can act in many movies. An actor can play more
than one role in the same movie. Suppose we try to represent this in our database using an Actor
table, a Movie table, and a Role table. The Role table has a foreign key to reference the Actor
table, plus the name of the role and the title of the movie.
a) There might be actors who do not have roles in the Role table
b) The actor referenced might not exist in the table
c) A role might list a movie title that does not exist in the Movie table
d) There could be more than one actor with the same name
2. Suppose we have the following relational model:
Movie(mov_id(PK), title, yr)
Person(pid(PK), fname, lname, gender)
Acts_In(actor_id(PFK), movie_id(PFK), role) -- actor_id references Person, movie_id references
Movie
What would be true of the following query?
SELECT fname, lname
FROM Movie m, Acts_In a, Person p
WHERE mov_id = movie_id AND actor_id = pid AND yr = 2022
a) It produces the names of actors who were in every movie released in 2022
b) It produces the names of all actors
c) It produces names of actors who had a role in a movie released in 2022
d) It produces the names of actors who were in exactly 1 movie released in 2022
