# ORM

## What is ORM?
ORM stands for Object-Relational Mapping or Object-Relational Mapper. ORM provides an object-oriented layer between relational databases, which allows developers to interact with their database using object-oriented languages like JavaScript.

## Implementation

### Sequalize
Sequalize is the Object-Relational Mapper that provides support for interacting with postgreSQL. Sequalize can also support other relational databases like MySQL, MariaDB, SQLite, and Microsoft SQL Server databases.

npm i sequalize

The postreSQL database driver must be installed along with Sequalize in order to make the database connection.

npm install pg pg-hstore

### ORM Folder
Contains all ORM files including unit test files for ensuring that the ORM code meets quality standards.

### init.js
Creates a Sequalize Instance for connecting to PostgreSQL.

const {Sequelize} = require('sequelize')

connect = function () {
  const sequelize = new Sequelize('email', 'email', 'email', {
    host: 'email-db',
    dialect: 'postgres',
    logging: false, //console.log, // Log to console or false (no logging of database queries)
    omitNull: true,
  })

  return sequelize
}

### connections.js
Initializes a connection model with connection attributes and options. Initializing the connection model creates a table inside of the database using those same attributes and options. Functionality is provided for creating, reading, updating, and deleting connections, as well as defining relations with the Contact table.

### contacts.js
Initializes a contact model with contact attributes and options. Initializing the contact model creates a table inside of the database using those same attributes and options. Functionality is provided for creating, reading, updating, and deleting contacts.

### contactsCompiled.js
Used for reading contact data while following conditions related to Demographic or Passport data.

### credentials.js
Initializes a credential model with credential attributes and options. Initializing the credential model creates a table inside of the database using those same attributes and options. Functionality is provided for creating, reading, updating, and deleting credentials.

### demographics.js
Initializes a demographic model with demographic attributes and options. Initializing the demographic model creates a table inside of the database using those same attributes and options. Functionality is provided for creating, reading, updating, and deleting demographics.

### emailVerification.js
Initializes a emailVerification model with email verification attributes and options. Initializing the emailVerification model creates a table inside of the database using those same attributes and options.

### images.js
Initializes an image model with image attributes and options. Initializing the image model creates a table inside of the database using those same attributes and options. Functionality is provided for creating, reading, updating, and deleting images.

### passport.js
Initializes a passport model with passport attributes and options. Initializing the passport model creates a table inside of the database using those same attributes and options. Functionality is provided for creating, reading, updating, and deleting passports, as well as defining relations with the Contact table.

### settings.js
Initializes a settings model with key and value attributes. Functionality is provided to create, read, update, and delete settings.

Initializing Setting:

Setting.init(
  {
    key: {
      type: DataTypes.TEXT,
      unique: true,
      primaryKey: true,
      allowNull: false,
    },
    value: {
      type: DataTypes.JSON,
      defaultValue: {},
      allowNull: false,
    },
  },
  {
    sequelize, // Pass the connection instance
    modelName: 'Setting',
    tableName: 'settings', // Our table names don't follow the sequelize convention and thus must be explicitly declared
    timestamps: false,
  },

### users.js
Initializes both a Users and Role model using attributes and options. Relations are also defined between the two tables. Functionality is provided to create, read, update, and delete both Users and Role.