src/Phinx/Db/Table.php
public function changePrimaryKey($columns)
    {
        $this->actions->addAction(new ChangePrimaryKey($this->table, $columns));

        return $this;
    }
public function changePrimaryKey($columns)
    {
        $this->actions->addAction(new ChangePrimaryKey($this->table, $columns));

        return $this;
    }
public function changePrimaryKey ( $ columns ) { $ this -> actions -> addAction ( new ChangePrimaryKey ( $ this -> table , $ columns ) ) ; return $ this ; }
Changes the primary key of the database table.

@param string|array|null $columns Column name(s) to belong to the primary key, or null to drop the key
@return $this
Changes the primary key of the database table .