How to count the number of documents in a mongodb collection

Question

I would like to know how to count the number of documents in a collection. I tried the follow

var value = collection.count();
&&
var value = collecti         


        

Answer 1

Execute Mongo shell commands in single line for better results.

To get count of all documents in mongodb

var documentCount = 0; db.getCollectionNames().forEach(function(collection) { documentCount++; }); print("Available Documents count: "+ documentCount);

Output: Available Documents count: 9

To get all count of document results in a collection

db.getCollectionNames().forEach(function(collection) { resultCount = db[collection].count(); print("Results count for " + collection + ": "+ resultCount); });

Output:

Results count for ADDRESS: 250 
Results count for APPLICATION_DEVELOPER: 950
Results count for COUNTRY: 10
Results count for DATABASE_DEVELOPER: 1
Results count for EMPLOYEE: 4500
Results count for FULL_STACK_DEVELOPER: 2000
Results count for PHONE_NUMBER: 110
Results count for STATE: 0
Results count for QA_DEVELOPER: 100

To get all dataSize of documents in a collection

db.getCollectionNames().forEach(function(collection) { size = db[collection].dataSize(); print("dataSize for " + collection + ":"+ size); });

Output:

dataSize for ADDRESS: 250 
dataSize for APPLICATION_DEVELOPER: 950
dataSize for COUNTRY: 10
dataSize for DATABASE_DEVELOPER: 1
dataSize for EMPLOYEE: 4500
dataSize for FULL_STACK_DEVELOPER: 2000
dataSize for PHONE_NUMBER: 110
dataSize for STATE: 0
dataSize for QA_DEVELOPER: 100