MigrationCreateAppointment.ts

import { MigrationInterface, QueryRunner, Table } from 'typeorm';

export default class CreateAppointments1586978594841
  implements MigrationInterface {
  public async up(queryRunner: QueryRunner): Promise<void> {
    await queryRunner.createTable(
      new Table({
        name: 'appointments',
        columns: [
          {
            name: 'id',
            type: 'uuid',
            isPrimary: true,
            generationStrategy: 'uuid',
            default: 'uuid_generate_v4()',
          },
          {
            name: 'provider',
            type: 'varchar',
            isNullable: false,
          },
          {
            name: 'date',
            type: 'timestamp with time zone',
            isNullable: false,
          },
          {
            name: 'created_at',
            type: 'timestamp',
            default: 'now()',
          },
          {
            name: 'updated_at',
            type: 'timestamp',
            default: 'now()',
          },
        ],
      }),
    );
  }

  public async down(queryRunner: QueryRunner): Promise<void> {
    await queryRunner.dropTable('appointments');
  }
}

MigrationUpdateFieldProviderId.ts

import {
  MigrationInterface,
  QueryRunner,
  TableColumn,
  TableForeignKey,
} from 'typeorm';

export default class AlterProviderFieldToProviderId1586995140083
  implements MigrationInterface {
  public async up(queryRunner: QueryRunner): Promise<void> {
    await queryRunner.dropColumn('appointments', 'provider');

    await queryRunner.addColumn(
      'appointments',
      new TableColumn({
        name: 'provider_id',
        type: 'uuid',
        isNullable: true,
      }),
    );

    await queryRunner.createForeignKey(
      'appointments',
      new TableForeignKey({
        name: 'AppointmentProvider',
        columnNames: ['provider_id'],
        referencedColumnNames: ['id'],
        referencedTableName: 'users',
        onDelete: 'SET NULL',
        onUpdate: 'CASCADE',
      }),
    );
  }

  public async down(queryRunner: QueryRunner): Promise<void> {
    await queryRunner.dropForeignKey('appointments', 'AppointmentProvider');

    await queryRunner.dropColumn('appointments', 'provider_id');

    await queryRunner.addColumn(
      'appointments',
      new TableColumn({
        name: 'provider',
        type: 'varchar',
      }),
    );
  }
}

modelAppointments

import {
  Entity,
  Column,
  PrimaryGeneratedColumn,
  CreateDateColumn,
  UpdateDateColumn,
  ManyToOne,
  JoinColumn,
} from 'typeorm';

import User from './Users';

@Entity('appointments')
class Appointment {
  @PrimaryGeneratedColumn('uuid')
  id: string;

  @Column()
  @JoinColumn({ name: 'provider_id' })
  provider_id: string;

  @ManyToOne(() => User)
  provider: User;

  @Column('time with time zone')
  date: Date;

  @CreateDateColumn()
  created_at: Date;

  @UpdateDateColumn()
  updated_at: Date;
}

export default Appointment;