edit table and add new index key with forge

According to the user guide it looks like it’s only possible when creating a table.

AddKey(): Adds a key to the set that will be used to create a table.

I guess you could execute an SQL query to create your index directly if it’s not possible with the Forge class.

YEs, i used $this->db->query to excute the raw query and create the index, it's worked! but i think CI4 should have funtion for this situation