I'm trying the following code:
const Conn = mongoose.createConnection('mongodb://127.0.0.1:27017/db');
const addresses = Conn.collection('users').aggregate([
{
$project: {
_id: false,
ethAddr: true,
}
}
]);
I receive the following error:
[...]\backend\node_modules\mongoose\lib\drivers\node-mongodb-native\collection.js:100
throw new Error('Collection method ' + i + ' is synchronous');
^
Error: Collection method aggregate is synchronous
at NativeCollection.<computed> [as aggregate] ([...]\backend\node_modules\mongoose\lib\drivers\node-mongodb-native\collection.js:100:15)
at file:///[...]/backend/scripts/dbGetMerkleRoot.js:11:46
at file:///[...]/backend/scripts/dbGetMerkleRoot.js:28:3
at ModuleJob.run (node:internal/modules/esm/module_job:185:25)
at async Promise.all (index 0)
at async ESMLoader.import (node:internal/modules/esm/loader:281:24)
at async loadESM (node:internal/process/esm_loader:88:5)
at async handleMainPromise (node:internal/modules/run_main:65:12)
What in cattle's name I'm doing wrong?
It seems to be a problem with the way mongoose connects to the database. Creating the connection but not connecting prior to invoking the aggregation method causes that exception to be thrown. I should've used it this way:
// create custom connection
const Conn = mongoose.createConnection();
// connect to database
await Conn.openUri('mongodb://127.0.0.1:27017/db');
// @type {AggregationCursor}
const addresses = Conn.collection('users').aggregate([
{
$project: {
_id: false,
ethAddr: true,
}
}
]);
console.log( await addresses.toArray() );
It's frustrating the exception itself is poorly documented.