In MySQL, we give an alias name for a column. Similarly, you can give an alias name for field name in MongoDB. The MongoDB equivalent syntax is as follows
db.yourCollectionName.aggregate( [ { "$project": { "_id": 0, "anyAliasName": "$yourFieldName" }} ]);
Let us first create a collection with documents
> db.selectFieldAsAnotherNameDemo.insertOne({"Name":"Larry"}); { "acknowledged" : true, "insertedId" : ObjectId("5c9d448827b86948e204ca91") } > db.selectFieldAsAnotherNameDemo.insertOne({"Name":"Robert"}); { "acknowledged" : true, "insertedId" : ObjectId("5c9d449027b86948e204ca92") } > db.selectFieldAsAnotherNameDemo.insertOne({"Name":"Sam"}); { "acknowledged" : true, "insertedId" : ObjectId("5c9d449527b86948e204ca93") } > db.selectFieldAsAnotherNameDemo.insertOne({"Name":"Mike"}); { "acknowledged" : true, "insertedId" : ObjectId("5c9d449927b86948e204ca94") }
Following is the query to display all documents from a collection with the help of find() method
> db.selectFieldAsAnotherNameDemo.find().pretty();
This will produce the following output
{ "_id" : ObjectId("5c9d448827b86948e204ca91"), "Name" : "Larry" } { "_id" : ObjectId("5c9d449027b86948e204ca92"), "Name" : "Robert" } { "_id" : ObjectId("5c9d449527b86948e204ca93"), "Name" : "Sam" } { "_id" : ObjectId("5c9d449927b86948e204ca94"), "Name" : "Mike" }
Following is the query for MongoDB equivalent of SELECT field AS `anothername`
> db.selectFieldAsAnotherNameDemo.aggregate( ... [ ... { "$project": { ... "_id": 0, ... "StudentName": "$Name" ... }} ... ]);
This will produce the following output
{ "StudentName" : "Larry" } { "StudentName" : "Robert" } { "StudentName" : "Sam" } { "StudentName" : "Mike" }