So basically I have a collection that holds ids which reference objects in another schema.
If I have an array which holds these ids, how can I map through the array and get the object associated with that id?
This is what I have so far but the response is just empty objects:
// this gives me an array of all the itemIds that a buyer has bought.
const prevPurchases = await Sales.find({ buyerId }).select(["itemId"]);
const item = prevPurchases.map(async (e) => {
try {
const item = await Item.findById(e.itemId).select(["image", "name"]);
return item;
} catch (e) {
return null;
}
});
await Promise.all(item);
return res.status(200).json({ item }); // just returns "{}, {}, {}, etc"
How can I fix this so that the objects contain the image and the name of item as I specified in the select. Thank you!
You can try collecting item ids in array and use $in operator to select all the items by single find query,
try {
const prevPurchases = await Sales.find({ buyerId }).select(["itemId"]);
let items = [];
if (prevPurchases.length) {
items = await Item.find({
_id: { $in: prevPurchases.map((e) => e.itemId) }
}).select(["image", "name"]);
}
return res.status(200).json({ items });
} catch (e) {
return null;
}