Auto-incrementing ID's in Loopback

Account.js

module.exports = function (Account) {

	Account.observe('before save', function addAccountId(ctx, next) {
		if (!ctx.isNewInstance) {
			debug('id is already set, returning', ctx.data);
			return next();
		}
		app.dataSources.db.connector.collection("Sequences").findAndModify({name: 'Account'}, [['_id', 'asc']], {$inc: {value: 1}}, {new: true}, function (err, rec) {
			if (err) {
				console.err(err);
			} else {
				if (ctx.instance) {
					ctx.instance.id   = rec.value.value;
				} else {
					ctx.data.id   = rec.value.value;
				}
			}
			next();
		});
	});
}

Account.json

{
  "name": "Account",
  "base": "PersistedModel",
  "idInjection": false,
  "properties": {
    "id": {
      "type": "Number",
      "id": true,
      "default": 0
    },
    ...
  }
}

Sequences.json

{
  "name": "Sequences",
  "base": "PersistedModel",
  "public": false,
  "idInjection": true,
  "options": {
    "validateUpsert": true
  },
  "properties": {
    "name": {
      "type": "string"
    },
    "value": {
      "type": "number",
      "default": 100000
    }
  },
  "validations": [],
  "relations": {},
  "acls": [],
  "methods": {}
}

Is this code applicable when connecting with a hyperledger network?

You can do something like in this example for loopback 4

let last_record = await this.testRepository.findOne({order: ['id DESC']});
if(last_record) invoice.id = last_record.id+1;

This will generate your model with the property:

@property({
    type: 'number',
    required: false,
    default: 1,
    generated: false
  })
  id: number;

Hopefully, this helps, please write me if there is any other code. Thanks

How we can change the no of digit id which is already in single digit and auto increment