@cashfarm/store
v0.8.0
Published
Library for easily defining and using your Read Model (as in DDD Read Model)
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Readme
CashFarm Store
Goal
To have a simple to use library for managing the Read Models. The kind we use when we want to store projections of events used in CQRS/ES arquitectures.
The goal of this library is to facilitate simple queries against a relational database. It was designed from start with denormalized tables in mind.
API
Store
The Store class represents a set of objects that can be stored and queried. It's NOT your entity repository (as in a DDD).
Table
Table child classes is how you map a DB table. To create a store you'll have to extend the Table class, define the database table name, fields and primary key.
Criteria
A class which reads the table definition and allows you to construct queries against it.
Example
export class Pet {
public id: number;
public breed: string;
public birthday: Date;
public gender: string;
public species: string;
}
@TableName('pets')
export class PetsTable extends Table {
@PK()
id = new NumberField('id');
species = new StringField('species');
breed = new StringField('breed');
birthday = new DateField('birthday');
gender = new StringField('gender');
}
@DtoClass(Pet)
@TableClass(PetsTable)
export class PetStore extends MysqlStore<PetsTable, Pet> {
constructor() {
super({} as IPool);
}
public allCats(): Promise<Array<Pet>> {
return this.find(query =>
query.where(p => p.species.equals('cat'))
);
}
public oneYearPetsAndAllDogs(): Promise<Array<Pet>> {
return this.find(q => q
.select(f => [f.birthday, f.gender])
.where(f => f.species.equals('cat'))
.groupBy([this[Sym.TABLE]['species'], f => f.gender])
.orderBy(f => f.breed, OrderDirection.Asc)
.orderBy(f => f.birthday, OrderDirection.Desc)
.limit(10)
);
}
}
const query = new Query(new PetsTable())
.whereAll(
f => f.gender.equals('male'),
f => f.birthday.before(new Date(2016, 1, 1, 2, 0, 0))
)
.where(f => f.id, [2, 4, 6, 8])
.whereAny(
f => f.species.equals('cat'),
f => f.species.equals('dog')
);
Development
- Install yarn if you didn't yet (
npm i -g yarn
) - Clone the repository
- From the root of the project run
yarn setup:dev
(ornpm run setup:dev
)
Profit!
To continuously compile and run tests simply run yarn test:watch