How to get Average using “Group By” in mysql php

Question

i to get "Average" with "GroupBy" in mysql

id      config_id       question    rating
1       68              lorem1      3
2       68              lorem2      5
3       69              lorem3      5
4       68              lorem1      NULL

i want to get average rating of every "config_id" ( not repeat ) i tried with following code,But not working for me

SELECT AVG(rating) AS AVERAGE 
FROM (SELECT config_id, AVG(rating) AS avg_rating 
      FROM "nps_ans" GROUP BY config_id) A
    ;
        

Answer 1

SELECT AVG(rating) AS AVERAGE
FROM nps_ans GROUP BY config_id;

Answer 2

if you need the average per config_id irrelevant of the question,

select config_id,AVG(rating) AS average from nps_ans group by config_id;

or

select question,config_id,AVG(rating) AS average from nps_ans group by config_id,question;

if you need the average rating per config and per question.