Im getting random data from my database using the aggregate but apparently some of them have their genre values in string not in array, How can i convert those random data genre from string to array?
const book = await Book.aggregate([
/* This is just for testing which books has genres in specific type
{
$match: { genre: { $type: "string" } }
},
*/
{
$sample: { size: 6 }
}
]);
sample data result(genres that are in type of string)
[
{
"_id": "62710ac63ad1bfc6d17030fe",
"title": "Birth of a Theorem",
"author": "Villani, Cedric",
"genre": "mathematics",
"publisher": "Bodley Head",
"dateOfPublication": "2002-02-28T00:00:00.000Z",
"noOfCopies": 16,
"type": "Book",
"form": "Non-fiction",
"isbn": "979-81202-479229-867673-6",
"dateAdded": "2002-11-28T00:00:00.000Z"
},
{
"_id": "62710ac63ad1bfc6d1703108",
"title": "All the President's Men",
"author": "Woodward, Bob",
"genre": "history",
"publisher": "Random House",
"dateOfPublication": "2018-02-19T00:00:00.000Z",
"noOfCopies": 56,
"type": "Book",
"form": "Non-fiction",
"isbn": "978-41428-6606587-937631-",
"dateAdded": "2011-02-23T00:00:00.000Z"
},
]
sample data result(genres that are in type of array)
[
{
"_id": "62710ac63ad1bfc6d17030be",
"title": "Superfreakonomics",
"author": "Dubner, Stephen",
"genre": [
"economics",
"computer_science"
],
"publisher": "HarperCollins",
"dateOfPublication": "2003-10-06T00:00:00.000Z",
"noOfCopies": 31,
"type": "Thesis",
"form": "Non-fiction",
"isbn": "978-35029-7186192-465859-7",
"dateAdded": "2009-02-12T00:00:00.000Z"
}
]
$sample is for documents instead of embedded array.
Update
db.collection.update({
genre: {
$type: "string"
}
},
[
{
$set: { genre: [ "$genre" ] }
}
],
{
multi: true
})
Aggregate
db.collection.aggregate([
{
$match: {
genre: {
$type: "string"
}
}
},
{
$set: {
genre: {
$cond: {
if: { $eq: [ { $type: "$genre" }, "string" ] },
then: [ "$genre" ],
else: "$genre"
}
}
}
}
])