Debugging: Cannot add foreign key constraint

Backstory:

I was working late to get a feature “working” before heading off to sleep. Somewhere in between autocomplete and matching definitions to Magento core files I had prepped my setup script. But upon running php bin/magento setup:upgrade instead of being all set I was greeted with a foreign key constraint issue to debug.

Foreign Key Constraint Cannot Be Added Error Message

Foreign key constraint from the UpgradeSchema.php in question:
->addForeignKey(
$setup->getFkName(self::CUSTOMMODULE_STORE_PIVOT_NAME, 'store_id', 'store', 'store_id'),
'store_id',
$setup->getTable('store'),
'store_id',
\Magento\Framework\DB\Ddl\Table::ACTION_CASCADE
)

So I went back to UpgradeSchema.php to take a closer look at things. I compared what I’d written to vendor/magento/module-store/Setup/InstallSchema.php since that’s the table I was creating my constraint agaisnt and realized that I’d set store_id on my pivot table to TYPE_INTEGER where it should have been TYPE_SMALLINT.

->addColumn(
'store_id',
\Magento\Framework\DB\Ddl\Table::TYPE_SMALLINT, //<-- I assumed this was going to be an integer, oops.
null, ['unsigned' => true, 'nullable' => false, 'primary' => true],
'Store ID'
)

Simple mistake, simple fix. I updated the type definition, re-ran setup, and was back in business. But the output was not that helpful and I was curious how to get better information about what actually went wrong in the event it wasn’t as apparent. And after a quick search here we are, log in to mysql from CLI and check the INNODB Engine Status logs.

Debugging:

ERROR 1215 (HY000): Cannot add foreign key constraint

mysql -u whomever -p
mysql> SHOW ENGINE INNODB STATUS;

The piece of the log we’re interested in for this use case is the aptly named latest foreign key error section.

------------------------
LATEST FOREIGN KEY ERROR
------------------------
2018-05-08 21:57:58 0x700001222000 Error in foreign key constraint of table ...

...
//The table name and query are output here but not relevant as it was output when the error was thrown during setup:upgrade. See below for the real issue:
...

Cannot find an index in the referenced table where the
referenced columns appear as the first columns, or column types
in the table and the referenced table do not match for constraint.
Note that the internal storage type of ENUM and SET changed in
tables created with >= InnoDB-4.1.12, and such columns in old tables
cannot be referenced by such columns in new tables.
Please refer to http://dev.mysql.com/doc/refman/5.7/en/innodb-foreign-key-constraints.html for correct foreign key definition.

TLDR; double check your column definitions. Make sure the data type and attributes match where appropriate. For example: This DOES mean both ID columns should be unsigned but DOES NOT mean your pivot table’s ID column should be auto incrementing. Put this in your memory bank and hopefully you’ll find it useful while debugging at some point.

SO to a stackoverflow answer from 2013 for still being helpful – https://stackoverflow.com/questions/15534977/mysql-cannot-add-foreign-key-constraint

More articles/tips/tool for debugging here.

M2: OPCache GUI

Now you can easily view the statistics for PHP OPcache in your Magento admin panel. TCMP OPcache GUI displays current memory usage / hit rate / configuration values. You can optionally enable the display of all cached scripts, including details about them, and a quick reset link for the menu (Stores > Configuration > TCMP Studio > OPcache).

Installation:


composer require tcmp/opcache
php bin/magento module:enable TCMP_OpCache
php bin/magento setup:updgrade
php bin/magento setup:static-content:deploy

Example:

TCMP OPcache GUI Example

More Information:

Supports: Magento 2.x (System Requirements) / PHP 7.x (OPCache Documentation)
The source: https://github.com/theycallmepepper/m2-opcache-gui
Packagist listing: https://packagist.org/packages/tcmp/opcache

Charts built with Chart.js
Version for Magento 1 (and inspiration for this version): https://github.com/SchumacherFM/Magento-OpCache/

M2: Marketplace EQP Code Standards + PHPStorm

What is MEQP?

Magento EQP Coding Standard is a set of rules and sniffs for PHP_CodeSniffer tool.

It allows automatically check your code against some of the common Magento and PHP coding issues, like:

– raw SQL queries;
– SQL queries inside a loop;
– direct class instantiation;
– unnecessary collection loading;
– excessive code complexity;
– use of dangerous functions;
– use of PHP superglobals;
– code style issues
– and many others.

Read more about it and see the source: Github: Magento Marketplace EQP

How do I use it?

This tool can be run via CLI against any extension by giving it the path but you can also more tightly integrate it into your development workflow with the following steps:


cd /path/to/your/docroot
mkdir meqp && cd meqp
git clone https://github.com/magento/marketplace-eqp.git .
composer install

Next open up PHPStorm and navigate to Preferences > Languages & Frameworks > PHP > Code Sniffer

You can set it to use the version of PHP_CodeSniffer installed with composer in the steps above. Just use “/path/to/your/docroot/meqp/vendor/bin/phpcs” as the path.

Next navigate to Preferences > Editor > Inspections > PHP > PHP Code Sniffer Validation

– Check “Show warnings as” and “Show Sniff Name”
– Choose MEQP2 from the down ( or MEQP1 for Magento 1.x code )
Originally posted as:
– Choose Coding Standard Custom
– Set your path tp the ruleset: “/path/to/your/docroot/meqp/MEQP2/ruleset.xml”

Thats it, now you can write your code according to Magento’s standards! You should see notifications right alongside your code indicating the issue and the sniff that is triggering it.

 

Updated for clarity and accuracy 3/25/2018.

M2: UI Component Form Field Validation

When building custom forms you’ll need to validate a few different types of data. Thankfully there are a number of validation rules already at your disposal in Magento’s core.


<!-- ... abbreviated usage example - vendor/module/view/adminhtml/ui_component/example_form.xml -->
<field name="title">
            <argument name="data" xsi:type="array">
                <item name="config" xsi:type="array">
                    <item name="dataType" xsi:type="string">text</item>
                    <item name="label" xsi:type="string" translate="true">Title</item>
                    <item name="formElement" xsi:type="string">input</item>
                    <item name="sortOrder" xsi:type="number">20</item>
                    <item name="dataScope" xsi:type="string">title</item>
                    <item name="validation" xsi:type="array">
                        <item name="required-entry" xsi:type="boolean">true</item>
                        <!-- ... additional rules go here -->
                    </item>
                </item>
            </argument>
        </field>
<!-- ... abbreviated usage example -->

A list of available rules from vendor/magento/module-ui/view/base/web/js/lib/validation/rules.js:

  • min_text_length
  • max_text_length
  • max-words
  • min-words
  • range-words
  • letters-with-basic-punc
  • alphanumeric
  • letters-only
  • no-whitespace
  • zip-range
  • vinUS //US VIN Numbers
  • dateITA
  • dateNL
  • time
  • time12h
  • phoneUS
  • phoneUK
  • mobileUK
  • stripped-min-length
  • email2
  • url2
  • credit-card-types
  • ipv4
  • ipv6
  • pattern //REGEX
  • validate-no-html-tags
  • validate-select
  • validate-no-empty
  • validate-alphanum-with-spaces
  • validate-data
  • validate-street
  • validate-phoneStrict
  • validate-phoneLax
  • validate-fax
  • validate-email
  • validate-emailSender
  • validate-password
  • validate-admin-password
  • validate-customer-password
  • validate-url
  • validate-clean-url
  • validate-xml-identifier
  • validate-ssn
  • validate-zip-us
  • validate-date-au
  • validate-currency-dollar
  • validate-not-negative-number
  • validate-zero-or-greater
  • validate-greater-than-zero
  • validate-css-length
  • validate-number
  • validate-integer
  • validate-number-range
  • validate-digits
  • validate-digits-range
  • validate-range
  • validate-alpha
  • validate-code
  • validate-alphanum
  • validate-date
  • validate-identifier
  • validate-zip-international
  • validate-state
  • less-than-equals-to
  • greater-than-equals-to
  • validate-emails
  • validate-cc-number
  • validate-cc-ukss
  • required-entry
  • checked
  • not-negative-amount
  • validate-per-page-value-list
  • validate-new-password
  • validate-item-quantity
  • equalTo
  • validate-file-type
  • validate-max-size
  • validate-if-tag-script-exist
  • date_range_min
  • date_range_max