PgSQL queries the largest or smallest data of a field in a group

As shown in the figure below , A one to many situation occurs after the left connection , I want to start from this " many " Take inside price The biggest piece of data :

terms of settlement , Add a new row to the query parameters :ROW_NUMBER() OVER(PARTITION by b.parent_charge_id ORDER BY c.price desc)idx

explain :

1.ROW_NUMBER： This function can number the groups

2.PARTITION by ： Yes parent_charge_id This field is grouped
The query result is :

You can see that the data has been pressed id Grouped , And numbered , The number is 1 Is the maximum we want , And then the value is 1 We can get the result we want :