Question

I have three tables

post

id | statement | date

features

id | feature

post_feature (many to many table between Post and Feature)

post_id | feature_id

I want to fire a query that will give me count of different distinct features and its respective features for the posts that are in given date period. I have just started learning SQL and I am not able to crack this one.

I tried the following one but not getting correct results.

 SELECT f.feature, count(f.feature)
   FROM  post_feature l 
   JOIN  features f ON (l.featureid = f.id AND l.featureid IN (
   select post.id from post where post.date > 'some_date'))
   GROUP BY f.feature

Answer 1

You can try like this:

       SELECT f.feature, count(f.feature)
       FROM  post_feature l 
       JOIN  features f ON l.featureid = f.id 
       JOIN  post p ON l.post_id =p.id 
       WHERE p.date > 'some_date'
       GROUP BY f.feature