How to display entries?

Question

Yii

There are two database tables. I want to display a cycle of records from one table, but at the same time, each record should display related records from the second table.
For example:
Russia 1000 people -
Moscow 500 people
- St. Petersburg 500 people.
And so on, other countries
As a result, the first table connects related records from the second table and calculates the sum of a certain column from the second table

Answer 1

Good evening.
Main link .
Working with connected data .

Answer 2

withJoin()