Gii crashes when table has invalid FKs referencing non-existent tables

[yii-bot]

This issue has originally been reported by @tekord at yiisoft/yii2#12358.
Moved here by @SilverFire.

---

What steps will reproduce the problem?

I have MySQL table:

CREATE TABLE `support_issue` (
    `id` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT,
    `type` VARCHAR(64) NULL DEFAULT NULL,
    `issued_by` INT(10) UNSIGNED NULL DEFAULT NULL,
    `created_at` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
    `updated_at` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
    `subject` VARCHAR(128) NOT NULL,
    `message` VARCHAR(2048) NOT NULL,
    `resolved_at` TIMESTAMP NULL DEFAULT NULL,
    PRIMARY KEY (`id`),
    INDEX `type` (`type`)
)
COLLATE='utf8_general_ci'
ENGINE=InnoDB
;

Then I try to generate model class through Gii generator:

Table Name
support_issue

Model Class 
SupportIssue

Namespace
common\models

Base Class
yii\db\ActiveRecord

Database Connection ID
db

[_] Use Table Prefix
Generate Relations
All relations

[_]  Generate Labels from DB Comments
[_]  Generate ActiveQuery
[CHECKED]  Enable I18N

Message Category
app
[_] Use Schema Name
Code Template
default (G:\xampp\htdocs\business-buddy\vendor\yiisoft\yii2-gii\generators\model/default)

What is the expected result?

Successfully generated model.

What do you get instead?

PHP Notice – yii\base\ErrorException

Trying to get property of non-object
1. in G:\xampp\htdocs\business-buddy\vendor\yiisoft\yii2-gii\generators\model\Generator.php at line 640

That happened just after 'Preview' button click.

Here is the screenshot: https://i.gyazo.com/5eff52de9661bcf7659fe1eada2a0f1d.png

Additional info

Q	A
Yii version	2.0.9
PHP version	7.0.8
Operating system	Windows 8.1

UPD: I just noticed this happens on any table. Tried to clean vendor folder and run composer update, but no effect.

[tekord]

I noticed that the error occurs if the option 'All relations' or 'All relations with Inverse' are selected. Maybe something wrong with my tables. Will look at it.

[tekord]

Yes, I have a table which has broken foreign keys (links to non-existing tables). I guess we need some checks in Gii model generator to handle this case.

[samdark]

Any idea on how to check it?

[tekord]

I found similar issue #34, it is closed, but my issue is still relevent. It has difference.

To reproduce execute the following SQL:

SET FOREIGN_KEY_CHECKS = 0;
CREATE TABLE `tour_to_image_links` (
    `product_id` INT(10) UNSIGNED NOT NULL,
    `image_id` INT(10) UNSIGNED NOT NULL,
    `position` SMALLINT(5) UNSIGNED NOT NULL DEFAULT '0',
    `type` TINYINT(3) UNSIGNED NOT NULL DEFAULT '0',
    PRIMARY KEY (`product_id`, `image_id`),
    INDEX `FK_tour_to_image_links_image` (`image_id`),
    CONSTRAINT `FK_tour_to_image_links_image` FOREIGN KEY (`image_id`) REFERENCES `images` (`id`) ON UPDATE CASCADE ON DELETE CASCADE,
    CONSTRAINT `FK_tour_to_image_links_product` FOREIGN KEY (`product_id`) REFERENCES `tours` (`id`) ON UPDATE CASCADE ON DELETE CASCADE
)
COLLATE='utf8_general_ci'
ENGINE=InnoDB
;

CREATE TABLE `images` (
    `id` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT,
    `file` VARCHAR(1024) NOT NULL,
    `url` VARCHAR(1024) NOT NULL,
    `title` VARCHAR(255) NULL DEFAULT NULL,
    `description` TEXT NULL,
    `created_at` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
    `updated_at` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
    `status` TINYINT(3) UNSIGNED NOT NULL,
    PRIMARY KEY (`id`)
)
COLLATE='utf8_general_ci'
ENGINE=InnoDB
ROW_FORMAT=COMPACT
AUTO_INCREMENT=22
;

SET FOREIGN_KEY_CHECKS = 1;

Then try to generate model for ANY table, not only of that new tables. Error will be thrown.

Next - drop the valid FK:

ALTER TABLE `tour_to_image_links`
    DROP FOREIGN KEY `FK_tour_to_image_links_image`;

Then NO ERROR thrown on model generation, although the table still has broken FK. This case is handled by that issue (#34).

Still don't know why this happening. Gonna check later, maybe give a solution.

[adipriyantobpn]

Same with me.

I just tried to do same steps done by @samdark at commit aeec43d in addInverseRelations(), then no error thrown again.