How to add column with foreign key within migration?

Yes, you need to use query() method now.

The feature to add keys to existing tables will be implemented in v4.3.0.
See https://github.com/codeigniter4/CodeIgni....rst#forge

PHP Code:

$this->forge->addKey(['category', 'name'], false, false, 'category_name');
$this->forge->addPrimaryKey('id', 'pk_actions');
$this->forge->addForeignKey('userid', 'user', 'id', '', '', 'userid_fk');
$this->forge->processIndexes('actions');
/* gives:
ALTER TABLE `actions` ADD KEY `category_name` (`category`, `name`);
ALTER TABLE `actions` ADD CONSTRAINT `pk_actions` PRIMARY KEY(`id`);
ALTER TABLE `actions` ADD CONSTRAINT `userid_fk` FOREIGN KEY (`userid`) REFERENCES `user`(`id`);
*/ 


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