[db]当数据库字段默认值为''是，php bin/swoft entity:create生成实体有问题

[uhonliu]

Q	A
Bug report?	yes
Feature request?	yes
Swoft version	1.0.0
Swoole version	2.1.12
PHP version	7.1.14
Runtime environment	CentOS 7

Details

当数据库字段默认值为''是，php bin/swoft entity:create生成实体字段有问题.

   /**
     * @var int $id 主键ID
     * @Id()
     * @Column(name="id", type=Types::INT)
     */
    private $id = '';

    /**
     * @var string $mobile 手机号
     * @Column(name="mobile", type=Types::STRING, length=11)
     * @Required()
     */
    private $mobile = '''';

    /**
     * @var string $email 邮箱
     * @Column(name="email", type=Types::STRING, length=50)
     * @Required()
     */
    private $email = '''';

    /**
     * @var string $auth_code 验证码
     * @Column(name="auth_code", type=Types::STRING, length=8)
     * @Required()
     */
    private $auth_code = '''';

    /**
     * @var string $auth_type 行为：注册，找回密码等
     * @Column(name="auth_type", type=Types::STRING, length=30)
     * @Required()
     */
    private $auth_type = '''';

[stelin]

已修复，db组件请更新至v1.1.4