sequelize-repository

sequelize-repository is a simple implementation of the repository pattern for sequelize

Table of contents

- SQRepository
- Query Methods
- Criteria
- TransactionRunner

$3

The SQRepository is the entry point to the library, it contains all repository methods, you must extend from this class to use it.

Example:
``
class MyRepository extends SQRepository {
constructor() {
super(MyRepository, db.MyModel, 'my_id' })
}
}

const repository = new MyRepository()

const entities = await this.repository.findById(1)
`
The SQRepository contains the following methods:
`
save(model,t)
findAll()
findAllWhere(query)
findAllByCriteriaAndPaginated({criteria, page, size, orderAttr})
findAndCountAll({condition, order, page, size, include})
findOne(query)
findById(id)
sum(field, criteria)
`

$3

Query methods are and easy way to generate simple queries without almost any code. You just have to write the method signature and parameters and SQRepository will do the rest.


| Keyword | Sample | Sequelize Snippet | Returns
| :--- | :--- |:--- |:----
| And | findAllByNameAndRole|model.findAll({ where: { name, role }, include: { all: true } }) | `[{entity}]`
| Paginated | findByNamePaginated |model.findAndCountAll({ where: { name }, limit, offset, include: { all: true } }) | `{ totalItems: 10, rows: [{entity}], totalPages: 15, currentPage: 0 }`

Example:
`
class MyRepository extends SQRepository {
constructor() {
super(MyRepository, db.MyModel, 'my_id' })
}
async findAllByNameAndEmail(name,email) {}
}

const repository = new MyRepository()

const entities = await this.repository.findAllByNameAndEmail("John", "Doe")
`

$3

Criteria is a class that represents sequelize queries in a simpler way, the CriteriaBuilder is used to build complex criterias easily. There are methods of the repository that expect a Criteria Object
Examples:
`
const { Op } = require('sequelize')
const criteria = new Criteria([{ field: 'client_id', value: 1234, condition: { [Op.eq]: 1234 }])
criteria.getCriteria() // -> { client_id: { [Op.eq] : 1234 } }
await myRepository.findAllWhere(criteria) // -> [{ client_id: 1234 }]
`
`
const builder = new CriteriaBuilder()
const criteria = builder.add('client_id', clientId, { [Op.eq]: clientId })
.add('created_date', fromDate, { [Op.eq]: clientId })
.add('status', 'FAILURE', { [Op.ne]: 'FAILURE' })
.add('request_id', null, { [Op.ne]: null })
.build()
criteria.getCriteria() // { client_id: { [Op.eq]: 1234 }, created_date: { [Op.eq]: 10/10/2021 } ...}
`

$3

The transaction runner is a solution to handle the sequelize transactions in just one place.
In order to use the "save" method of the repository you must execute it inside a transaction.
Example:
`
const db = require('../models')
const result = await TransactionRunner.run(db, async (t) => {
const entity = await repository.save({ id: 1, name: 'John', lastName: 'Doe' }, t)
return entity
})
``