EZ4: Database

It uses the power of reflection to provide a contract that determines how to build and connect database components.

Getting started

Install

npm install @ez4/database @ez4/local-database @ez4/aws-aurora -D

You can use @ez4/aws-dynamodb instead of @ez4/aws-aurora for NoSQL database.

Create database

// file: db.ts
import type { Environment, Service } from '@ez4/common';
import type { Database } from '@ez4/database';

// MyDb message
type MyTableSchema = {
  foo: string;
  bar: number;
};

// MyDb declaration
export declare class MyDb extends Database.Service {
  client: Client<Db>;

  engine: PostgresEngine;

  tables: [
    Database.UseTable<{
      name: 'test_table';
      schema: MyTableSchema;
      indexes: {
        foo: Index.Primary;
      };
    }>
  ];
}

Use database

// file: handler.ts
import type { Service } from '@ez4/common';
import type { myDb } from './db';

// Any other handler that has injected MyDb service
export async function anyHandler(_request: any, context: Service.Context<DummyService>) {
  const { myDb } = context;

  // Insert one record
  await myDb.test_table.insertOne({
    data: {
      foo: 'foo',
      bar: 123
    }
  });

  // Find one record
  const result = await myDb.test_table.findOne({
    select: {
      bar: true
    },
    where: {
      foo: 'foo'
    }
  });
}

Database properties

Service

| Name | Type | Description | | ----------- | ------------------------- | ------------------------------------------------ | | scalability | Database.UseScalability<> | Scalability configuration. | | tables | Database.UseTable<> | Describe all available tables for the service. | | engine | Database.UseEngine<> | Determines which database engine to use. | | variables | object | Environment variables associated to all streams. | | services | object | Injected services associated to all streams. |

Use type helpers for scalability and tables properties.

Tables

| Name | Type | Description | | --------- | ------------------------- | --------------------------- | | stream | Database.UseTableStream<> | Table stream configuration. | | name | string | Table name. | | schema | object | Table schema. | | relations | object | Table relations. | | indexes | object | Table indexes. |

Streams (DynamoDB)

| Name | Type | Description | | ------------ | -------- | ------------------------------------------------ | | listener | function | Life-cycle listener function for the stream. | | handler | function | Entry-point handler function for the stream. | | variables | object | Environment variables associated to the stream. | | logRetention | integer | Log retention (in days) for the handler. | | memory | integer | Memory available (in megabytes) for the handler. | | timeout | integer | Max execution time (in seconds) for the route. |

Streams is a DynamoDB feature, thus unavailable for Aurora Postgres.

Examples

• Get started with Aurora RDS
• Get started with DynamoDB
• Aurora RDS CRUDL
• DynamoDB CRUDL
• DynamoDB streams
• Schedule manager
• Storage manager

Providers

• Local provider
• AWS Aurora provider
• AWS DynamoDB provider

License

MIT License