List of users who do not have transactions after 'x' date - sql

Question

I have a query I need to create that pulls data from three different tables. Essentially the end result is to pull data for users that have not had any activity on a users' account since 07/01/2018, but they have to have an account plan as "x." Is there a way to manipulate this query I've created to get it to display what I need it to? Maybe somehow correlate it to a count of 0 on the TRANDATE column? Very lost here and could use some help!
select p.ID as ID, p.LAST as LastName, p.FIRST as FirstName
From gl
inner join p
on p.ID = gl.PID
left join psp
on psp.PLANNUM = gl.ACCNUM
where gl.ACCNUM = 'x'
and psp.ACTIVE = 1
and gl.TRANDATE <= to_date('07/01/2018', 'MM/DD/YYYY')
;
commit;
Thank you all very much and please let me know if there's anything else I can provide here.

Answer 1

You don't really specify your table structure, so I'm kinda guessing here. Does your "gl" table have more than one record per PID+ACCNUM? What are the primary keys? There are a lot of extra details you could provide.
select p.ID as ID, p.LAST as LastName, p.FIRST as FirstName, g.maxdate
From (select gl.PID, gl.ACCNUM, max(gl.TRANDATE) as maxdate
from gl
where gl.ACCNUM = 'x'
group by gl.PID, gl.ACCNUM) g
inner join p
on p.ID = g.PID
inner join psp
on psp.PLANNUM = g.ACCNUM
and psp.ACTIVE = 1
where g.maxdate <= to_date('07/01/2018', 'MM/DD/YYYY')
;
Also, (a) you don't need a commit on a select, and (b) a left/outer join is an inner join when you have its column in the WHERE clause (psp.ACTIVE = 1).

Answer 2

I would simply use aggregation and max() in the having clause:
select p.ID as ID, p.LAST as LastName, p.FIRST as FirstName
from gl inner join
p
on p.ID = gl.PID inner join
psp
on psp.PLANNUM = gl.ACCNUM
where gl.ACCNUM = 'x' and psp.ACTIVE = 1
group by p.ID, p.LAST, p.FIRST
having max(gl.TRANDATE) <= date '2018-07-01';
Note that the where condition on psp.ACTIVE turns the outer join into an inner join, so I changed the join type for readability.

Answer 3

Since all your display fields are from p, you can do grouping in inner queryfor the p.id which occur more than once. All the rest of ids(not in) are of your interest.
select p.ID as ID, p.LAST as LastName, p.FIRST as FirstName
From p where p.ID not in (
select p.ID From gl
inner join p on p.ID = gl.PID
left join psp on psp.PLANNUM = gl.ACCNUM
where gl.ACCNUM = 'x'
and psp.ACTIVE = 1
and gl.TRANDATE <= to_date('07/01/2018', 'MM/DD/YYYY')
group by p.ID
having count(1) >= 1)