https://github.com/spurreiter/loopback-optimistic-lock
demo project for realizing optimistic locking with loopback
https://github.com/spurreiter/loopback-optimistic-lock
Last synced: 3 months ago
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demo project for realizing optimistic locking with loopback
- Host: GitHub
- URL: https://github.com/spurreiter/loopback-optimistic-lock
- Owner: spurreiter
- Created: 2019-02-23T12:28:05.000Z (about 6 years ago)
- Default Branch: master
- Last Pushed: 2019-02-23T12:31:05.000Z (about 6 years ago)
- Last Synced: 2025-01-07T06:37:51.284Z (4 months ago)
- Language: JavaScript
- Size: 9.77 KB
- Stars: 0
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Codeowners: CODEOWNERS
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README
# loopback-optimistic-lock
This is a small test project which adds optimistic locking to loopback models.
The attribute `updatedAt` is used to search for locked documents.
## test
1. start your mongoDb
2. start the server
node server/server.js
3. An update with correct `updatedAt` timestamp
node index.js
4. An update with outdated timestamp
node index.js --fail
Pls. check `common/models/coffee-shop.js` for implementation details.
This project currently requires a custom fork of [loopback-datasource-juggler](https://github.com/spurreiter/loopback-datasource-juggler).
## optimistic locking at the database
Plain update with mongoDb, to give you an idea...
create document
```
db.getCollection('test').insertOne({
name: "test", version: 1.0, updatedAt: new Date()
})
```
find document
```
var _id = ObjectId("5c34f76724b9aef1f8f2aaf5")
db.getCollection('test').find({ _id })
```
update document
```
var _id = ObjectId("5c34f76724b9aef1f8f2aaf5")
var updatedAt = ISODate("2019-01-08T18:41:15.826Z")
db.getCollection('test').update(
{ _id, updatedAt }
,{ $set: { name: "test2", updatedAt: new Date() }
,$inc: { version: 1 }
}
)
db.getCollection('test').find({ _id })
```
## credits
This test project builds on [loopback-getting-started][].
## license
- Unknown: Code from [loopback-getting-started][].
- [Unlicense][]: For all changes compared to [loopback-getting-started][].
[Unlicense]: https://unlicense.org
[loopback-getting-started]: https://github.com/strongloop/loopback-getting-started