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While doing the development everyones know that no one can remember all of the queries and commands. So in the blog I am covering most used Mongo DB queries. Mongo DB Queries By Education Funda Mongo DB Queries For Studio 3T and In Your Code Fetch Queries: db . getCollection ( "collectionName" ). find ( { FILTER_COLUMN_NAME : 'VALUE' }, { PROJECTION_COLUMN_NAME_1 : 1 , PROJECTION_COLUMN_NAME_2 : 1 } ) Get Duplicates Records db . getCollection ( "collectionName" ). aggregate ([ { "$group" : { "_id" : "$DUP_COL_NAME" , "count" : { "$sum" : 1 } } }, { "$match" : { "_id" : { "$ne" : null } , "count" : { "$gt" : 1 } } }, { "$project" : { "DUP_COL_NAME" : "$_id" , "_id" : 0 } } ]) Count Query db . getCollection ( "collectionName" ). countDocuments ( { FILTER_COL_1 : ...

In This Blog We Will See Complete Guide For Using Joins With Lookup in Mongoose MongoDB Mongoose - Education Funda Simply in MongoDB Mongoose we can use Aggregate Query with $ lookup to get data basis upon JOINS. such as below: await MainModel . aggregate ([ { $match : { "COLUMN_NAME" : value } }, { $lookup : { from : 'relation_collection_name' , localField : 'relation_collection_primary_key' , foreignField : 'this_table_foreign_key' , as : 'ALIASING' } } ]); With above query new column added with ALIASING in which relation collection data will also come. To get data in Object format instead of Array we can use $unwind like below: await MainModel . aggregate ([ { $match : { "COLUMN_NAME" : value } }, { $lookup : { from : 'relation_collection_name' , ...