In this post, we will get to know MongoDB Aggregation : How to get total records to count, which we can perform by simply using an in built function court and get the desired output.
Aggregation
Here we have taken an example to get things done and understand the implementation.
from pymongo import MongoClient
client = MongoClient( 'localhost', 27017)
db = client[ 'mydatabase']
collection = db[ 'mycollection']
result = collection. aggregate([{ '$count': 'total_records' }])
print(result. next()['total_ records'])
In the given example above first, we created a mongo client instance and connect it to the database which is nothing but the name of the database and the name of the collection here is my collection.
And here we used the aggregate() function for initiating or starting the aggregate pipeline with a single stage: Which is nothing but the count() operator which is used for returning a single value as the output of the function where the returning digit is nothing but the all of documents in the collection we provided.
There are a few \things we need to keep in mind for using the count operator which is followed.
It is said to be a bit slower than some other operators which does the same thing for example take an example of count_document() method of PyMongo which is used for a large data set or a large collection as compared to count() so select the operator wisely for use as per the requirement of the project.
We can also use the operator match for filtering the data before the count operator which we use in special conditions like when we want to count the special entries only. And similar to that we can also use the same for counting the number in a particular group we are working with, which means we can count the number of each group we created by grouping the whole data as per requirements.
As if we use the only count operator it will return only a single digit answer but in case we want to make it more self explanatory means if we want to add some more additional columns to it we can do so by simply giving the name of the field we want and even we can rename the name of the field only for display purpose.
To learn more about MongoDB Aggregation: How to get all the records count visit: by stack overflow
To learn more about MongoDB solutions to different problems faced in MongoDB along with concepts and tutorials on one different topic visit: MongoDB Problems And Tutorials.
