I have an issue with this code
const doc = await req.db
.collection('clients')
.find({}, { lName: 1, fName: 1, id: 1 })
giving the typescript error
Type error: Argument of type '{ lName: number; fName: number; id: number; }' is not assignable to parameter of type 'FindOneOptions<any>'.
how can I fix this? thanks!
This should resolve it for you:
const doc = await req.db
.collection<Client>('clients')
.find({ lName: "", fName: "", id: 1 })
The .find() method of Db takes one or two options, where the first option is the FilterQuery and the second is FindOneOptions.
find<T = TSchema>(query?: FilterQuery<TSchema>): Cursor<T>;
find<T = TSchema>(query: FilterQuery<TSchema>, options?: FindOneOptions<T extends TSchema ? TSchema : T>): Cursor<T>;
The options for the second argument are things like sort and limit, not the object to find. What you have in the second argument is the FilterQuery which needs to be the first argument.
The FilterQuery type is generic, so in order for typescript to know that we are filtering clients, we need to pass the generic when calling collection<Client>('clients'). That will cause it to return a collection of Client.
This is the interface I used, but I'm sure there are more properties
interface Client {
lName: string;
fName: string;
id: number;
}
Now, if you pass an invalid type to .find(), typescript knows and will throw and error.
.find({ lName: 1, fName: 1, id: 1 })
This is now an error because I said that fName and lName must be string.
.find({ lName: 1, fName: 1, id: 1 }) needs to be .find({}, { lName: 1, fName: 1, id: 1 }) to have ALL ENTRIES returned while only selecting certain fields from EVERY entry.