const { custom_lookup, custom_unwind} = require('node-lookup-helper');

User Collection Name With - user_collection

| _id | name | email | status | |----|----|----|----| | ObjectId("61cc1341089ecb6f5307de6c") | Demo | [email protected] | ACTIVE |

User favourite fruit Collection Name With - user_favourite_collection

| _id | user_id | favourite_fruit | Status | |----|----|----|----| | ObjectId("61cc1060089ecb6f5307ddc3") | ObjectId("61cc1341089ecb6f5307de6c") | Apple | ACTIVE | | ObjectId("61b19d0c7aa9361af2d5c747") | ObjectId("61cc1341089ecb6f5307de6c") | Orange | ACTIVE |

Get multiple records in array from - user_favourite_collection -

custom_lookup("user_favourite_collection", "_id", "user_id", "user_favourite", ['_id','favourite_fruit'])

const result = await user_collection.aggregate([
    {
        $match: {}
    },
    custom_lookup("user_favourite_collection", "_id", "user_id", "user_favourite", ['_id','favourite_fruit'])
]);

Result:

_id : "61cc1341089ecb6f5307de6c",
name : "Demo",
email : "[email protected]",
status : "ACTIVE"
user_favourite : [
	{
		_id : ObjectId("61cc1060089ecb6f5307ddc3"),
		favourite_fruit : "Apple"
	},
	{
		_id : ObjectId("61b19d0c7aa9361af2d5c747"),
		favourite_fruit : "Orange"
	}
]

Get single record in object from - user_favourite_collection -

custom_lookup("user_favourite_collection", "_id", "user_id", "user_favourite", ['_id','favourite_fruit'])

custom_unwind("user_favourite")

const result = await user_collection.aggregate([
    {
        $match: {}
    },
    custom_lookup("user_favourite_collection", "_id", "user_id", "user_favourite", ['_id','favourite_fruit']),
    custom_unwind("user_favourite")
]);

Result:

_id : "61cc1341089ecb6f5307de6c",
name : "Demo",
email : "[email protected]",
status : "ACTIVE"
user_favourite : {
	_id : ObjectId("61cc1060089ecb6f5307ddc3"),
	favourite_fruit : "Apple"
}