PHP Database builder

execute_file.php

<?php

// requires and namespaces

$userTable = new Migrations\Table('users', function ($field) {
  $field->primaryKey('id')->unsigned();
  $field->varChar('username');
  $field->integer('age')->nullable();
});

$postTable = new Migrations\Table('posts', function ($field) {
  $field->primaryKey('id')->unsigned();
  $field->varChar('title');
  $field->varChar('body')->nullable();
})

Field.php

<?php

namespace my\name\space;

class Field {

  private $table; // parent table is Table class
  public $type; // field type, i.e. varchar, string etc..
  public $name; // field name
  public $isNullable = false;
  public $isUnSigned = false;
  public $hasDefault = false;

  // set parent table and push this class instance
  function __construct ($table) {
    $this->table = $table;
    array_push($this->table->fields, $this); 
  }
  
  // create new class and set some field
  public function newField ($name, $type) {
    $field = new Field($this->table);
    $field->name = $name;
    $field->type = $type;
    return $field;
  }
  
  public function primaryKey ($name) {
    return $this->newField($name, 'AUTO_INCREMENT');
  }

  public function varChar ($name) {
    return $this->newField($name, 'var_char');
  }

  public function integer ($name) {
    return $this->newField($name, 'integer');
  }

  public function boolean ($name) {
    return $this->newField($name, 'boolean');
  }

  public function date ($name) {
    return $this->newField($name, 'date');
  }

  public function nullable () {
    $this->isNullable = true;
    return $this;
  }

  public function unsigned () {
    $this->isUnSigned = true;
    return $this;
  }

  public function default ($default) {
    $this->hasDefault = $default;
    return $this;
  }

}

Table.php

<?php
namespace my\name\space;

class Table {

  public $type = 'innoDB';
  public $fields = [];
  public $name;

  function __construct($name, $fields) {
    $this->name = $name;
    $fields(new Field($this));
    array_splice($this->fields, 0, 1);
  }

  public function setType ($type) {
    $this->type = $type;
    return $this;
  }

}