Inserting data into multiple tables

Hello,

In basic sql command to insert data into multiple table with foreign key relation the last inserted id is helpful. In codeigniter how can I insert data into  multiple table with foreign key relation. I'm reading at some helpful tutorials like using transactions. Can someone teach me how to implement in codeigniter or any code snippets that can share in order to help me. I'm still learning this framework.

Thanks

Have you read https://www.codeigniter.com/user_guide/d...tions.html ?

I already read this. What Im trying to emphasize is does transaction is the way to insert data from a foreign key constraint? Or theirs other way.