`addForeignkey()` without a constraint/name creates a constraint, which has a integer name

[LordSimal]

So this is a weird issue.

I have migrations which add a foreign key like so (the old fashioned way)

->addForeignKey('staff_member_id', 'staff_members', ['id'], ['delete'=> 'CASCADE'])

which then created the table for tests fine, but causes problems combined with

ConnectionHelper::dropTables('test');

when used in tests/bootstrap.php

Why? Because the method to drop all tables uses the constraint names to get its details and throws this error

Error in bootstrap script: TypeError:
Cake\Database\Schema\TableSchema::getConstraint(): Argument #1 ($name) must be of type string, int given, called in /Users/kevin/Documents/sunlime/alfred/vendor/cakephp/cakephp/src/Database/Schema/MysqlSchemaDialect.php on line 1013
#0 /Users/kevin/Documents/sunlime/alfred/vendor/cakephp/cakephp/src/Database/Schema/MysqlSchemaDialect.php(1013): Cake\Database\Schema\TableSchema->getConstraint(1)
#1 /Users/kevin/Documents/sunlime/alfred/vendor/cakephp/cakephp/src/TestSuite/ConnectionHelper.php(105): Cake\Database\Schema\MysqlSchemaDialect->dropConstraintSql(Object(Cake\Database\Schema\TableSchema))
#2 /Users/kevin/Documents/sunlime/alfred/tests/bootstrap.php(56): Cake\TestSuite\ConnectionHelper::dropTables('test')
#3 /Users/kevin/Documents/sunlime/alfred/vendor/phpunit/phpunit/src/TextUI/Configuration/BootstrapLoader.php(61): include_once('/Users/kevin/Do...')
#4 /Users/kevin/Documents/sunlime/alfred/vendor/phpunit/phpunit/src/TextUI/Configuration/BootstrapLoader.php(36): PHPUnit\TextUI\Configuration\BootstrapLoader->load('/Users/kevin/Do...')
#5 /Users/kevin/Documents/sunlime/alfred/vendor/phpunit/phpunit/src/TextUI/Application.php(132): PHPUnit\TextUI\Configuration\BootstrapLoader->handle(Object(PHPUnit\TextUI\Configuration\Configuration))
#6 /Users/kevin/Documents/sunlime/alfred/vendor/phpunit/phpunit/phpunit(104): PHPUnit\TextUI\Application->run(Array)
#7 {main}

as this method expects a string being passed down for the constraint name, but the generated constraint name is 1 as an integer for me.

Technically this would be fixable by adjusting constraints() to not use array keys and instead actually get the name from the constraint object like so

public function constraints(): array
{
    return array_map(function ($constraint) {
        return $constraint->getName();
    }, $this->_constraints);
}

but I'd rather fallback to some auto generated constraint name in migrations.

[LordSimal]

The other fix for my local test setup would be to adjust the migration and add a name like so

->addForeignKey('staff_member_id', 'staff_members', ['id'], ['delete'=> 'CASCADE', 'name' => 'fk_staff_members_work_times_staff_member_id'])

but this does not fix the constraint name in the live DB where this migration has already been applied.

[dereuromark]

We can auto generate the key name if missing. But yes, this would not fix issues into the past.

PS: I can see PostgresAdapter and SqlserverAdapter already auto-generate names, but MysqlAdapter and SqliteAdapter don't.

[dereuromark]

Actually:
No backwards compatibility issue for existing databases - they keep their ibfk_1 names, and the diff tool reads those actual names.