Question

I’ve two tables, Table1(News) and Table2(Subscribers).

Table1: id, news_title

Table2: id, news_id, user_id

Table1
id | news_title
--------------
 1 | News 1
 2 | News 2
 3 | news 3

Table2
id | news_title_id | user_id
----------------------------
 1 | 1             | 1
 2 | 1             | 2
 3 | 2             | 3

I need a query result like this.

news_title | subscribers
------------------------
News 1     | 2
News 2     | 1
News 3     | 0

Any help?

Answer 1

A simple aggregate COUNT(*) with a LEFT JOIN will do the job here. LEFT JOIN and COUNT(*) (rather than COUNT(user_id)) are used to be sure titles with zero subscribers still return a row.

SELECT 
  news_title,
  COUNT(Table2.*) AS subscribers
FROM Table1 LEFT JOIN Table2 ON Table1.id = Table2.news_title_id
GROUP BY news.title