Question

I have a database design for a survey.

I have a Table USERS with user_id PK and name.

QUESTION with question_id and question_text.

POSSIBLE_ANSWER with answer_id PK ,value, text.

Also, I have USER_ANSWERS with user_id from users , Question_id , answer_id .

Also some 3 other tables not relevant to my question.

What I need is select avg(value) for all users where name like’m%’.

Hope this is clear thanks.

Answer 1

try the following:

select avg(PA.value)
from POSSIBLE_ANSWER PA
inner join USER_ANSWERS UA on PA.answer_id = UA.answer_id
inner join USERS U on U.user_id = UA.user_id 
where U.name like 'm%'