Add schema builder about ts-sql-builder

[os-moussao]

As far as fcffea4, all features are supported !

extended example:

@Index({ name: 'idx_user_email', columns: ['email'], unique: true })
@Index({ name: 'idx_user_username', columns: ['username'], unique: true })
@Table('users')
class User {
  @PrimaryKey()
  @Column({ type: 'SERIAL' })
  id!: number;

  @Column({ type: 'VARCHAR(255)', nullable: false })
  name!: string;

  @Column({ type: 'VARCHAR(65)', nullable: false, unique: true })
  username!: string;

  @Column({ type: 'INTEGER', check: 'age >= 18' })
  age!: number;

  @Column({ type: 'VARCHAR(255)', unique: true })
  email!: string;

  @Column({
    name: 'created_at',
    type: 'TIMESTAMP',
    default: () => 'CURRENT_TIMESTAMP',
  })
  createdAt!: Date;

  @Column({ type: 'BOOLEAN', default: true })
  activated!: boolean;

  @ForeignKey({ reference: 'address(id)', onDelete: 'NO ACTION' })
  @Column({ type: 'INTEGER' })
  addressId!: number;
}

console.log(tableSchema(User));

Produces:

CREATE TABLE users (
  id SERIAL,
  name VARCHAR(255) NOT NULL,
  username VARCHAR(65) NOT NULL UNIQUE,
  age INTEGER CHECK (age >= 18),
  email VARCHAR(255) UNIQUE,
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
  activated BOOLEAN DEFAULT true,
  addressId INTEGER,
  PRIMARY KEY (id),
  FOREIGN KEY (addressId) REFERENCES address (id) ON DELETE NO ACTION
);

CREATE UNIQUE INDEX idx_user_username ON users (username);

CREATE UNIQUE INDEX idx_user_email ON users (email);