I'm working on a query that returns an hourly time series for a given day, but I need to filter by a particular column on another table, which in my case is the user id.

This is my current query, which returns the submission count for every hour of the current day:

```
SELECT hours, count(s.id)
FROM generate_series(current_date, current_date + interval '23h', cast('1h' as interval)) hours
         left join submission s on hours = date_trunc('hour', s.submitted_date)
group by hours
order by hours;

```

[![enter image description here](https://i.stack.imgur.com/L90DQ.png)](https://i.stack.imgur.com/L90DQ.png)

However, these records are irrespective of user id, so when I filter by user id with a query like this it will only return the hours for which a submission for that user was received when instead I need it to return records for every hour much like the query above:

```
SELECT hours, count(s.id)
FROM generate_series(current_date, current_date + interval '23h', cast('1h' as interval)) hours
    left join submission s on hours = date_trunc('hour', s.submitted_date)
    left join form f on s.form_custom_id = f.custom_id
    left join "user" u on f.user_id = u.id
    where u.id = 4
group by hours
order by hours;

```

[![enter image description here](https://i.stack.imgur.com/WmHI9.png)](https://i.stack.imgur.com/WmHI9.png)

Here's my SQL Fiddle: <http://www.sqlfiddle.com/#!17/a8d80/1>

Any help would be greatly appreciated!