Counting data from 2 tables

[JohnL]

I have two tables: USERS and PICTURES

Sample data for USERS:
[table]
[tr][td]id[/td][td]birth_date[/td][/tr]
[tr][td]1[/td][td]1970-01-01[/td][/tr]
[tr][td]2[/td][td]1987-01-01[/td][/tr]
[tr][td]3[/td][td]1980-01-01[/td][/tr]
[tr][td]4[/td][td]1981-01-25[/td][/tr]
[tr][td]5[/td][td]1982-07-01[/td][/tr]
[tr][td]6[/td][td]1985-01-25[/td][/tr]
[tr][td]7[/td][td]1978-07-01[/td][/tr]
[tr][td]8[/td][td]1970-01-01[/td][/tr]
[/table]

Sample data for PICTURES
[table]
[tr][td]id[/td][td]pictureNo[/td][/tr]
[tr][td]1[/td][td]1[/td][/tr]
[tr][td]1[/td][td]2[/td][/tr]
[tr][td]1[/td][td]3[/td][/tr]
[tr][td]7[/td][td]1[/td][/tr]
[tr][td]7[/td][td]2[/td][/tr]
[/table]

The following query
SELECT floor(period_diff(extract(year_month from NOW()),extract(year_month from birth_date))/12) as age, count(*) FROM db.USERS u group by age order by age;

Would return
[table]
[tr][td]age[/td][td]count(*)[/td][/tr]
[tr][td]20[/td][td]1[/td][/tr]
[tr][td]22[/td][td]1[/td][/tr]
[tr][td]24[/td][td]1[/td][/tr]
[tr][td]26[/td][td]1[/td][/tr]
[tr][td]27[/td][td]1[/td][/tr]
[tr][td]28[/td][td]1[/td][/tr]
[tr][td]37[/td][td]2[/td][/tr]
[/table]

This is half my Job done. I do not know how to go about doing the next task which is to count how many users has uploaded at least one picture within that age group.

What query is required to return a result looking something like
[table]
[tr][td]age[/td][td]age count(*)[/td][td]pictures count(*)[/td][/tr]
[tr][td]20[/td][td]1[/td][td]0[/td][/tr]
[tr][td]22[/td][td]1[/td][td]0[/td][/tr]
[tr][td]24[/td][td]1[/td][td]0[/td][/tr]
[tr][td]26[/td][td]1[/td][td]0[/td][/tr]
[tr][td]27[/td][td]1[/td][td]1[/td][/tr]
[tr][td]28[/td][td]1[/td][td]0[/td][/tr]
[tr][td]37[/td][td]2[/td][td]1[/td][/tr]
[/table]

[fenway]

Not so simple... since you need the user uids for each user within each age range.  You'll need to run a subquery to determine these, and then join them in.