postgresql - How to add query results to table in SQL?

Question

I am trying to add the results of a query to an existing table, dependent on the values of an existing column. For example, using the table below

Store	Sales	Weekday
10	11000	Weekday
11	5000	Weekday
12	8000	Weekday
10	19000	Weekend
11	20000	Weekend
12	5000	Weekend

question from:https://stackoverflow.com/questions/65644392/how-to-add-query-results-to-table-in-sql

Answer 1

As mentioned in other answer, don't store calculated values in table.

But if you want to know how it can be done, then one of the options is to use the corelated query as follows:

UPDATE store_sales s SET s.weekday_avg = (
    SELECT AVG(ss.Sales) AS weekday_avg
    FROM store_sales ss
    WHERE s.Weekday = ss.weekday
      And ss.store=s.store
);