Need help catching all members in my query

Question

Here’s the problem: I think my very last statement is causing the report to pull ONLY people who’ve actually ever logged in. Is there any way to still pull only the latest LOGIN_TIME OR a NULL/Empty time?
Thanks for anything you can tell me!
select
PS.LNAME,
PS.FNAME,
SI.LOGIN_ID,
PS.EMAIL_ADDR,
US.col_num_20 Library_Type,
US.col_num_30 Place_of_Work,
US.col_num_10 Was_Rejected,
US.col_num_70 Date_Created,
PS.POSTAL,
PS.STATE,
DECODE (PS.NOTACTIVE, 'Y', 'N', 'Y') AS is_active, PS.NOTACTIVE,
SI.LOGIN_TIME,
SI.SEQ_NUM
from PA_STUDENT PS, PV_STUD_USER US, PA_LOGIN_SESSION_INFO SI
where PS.STUD_ID = US.STUD_ID (+)
and PS.STUD_ID = SI.LOGIN_ID (+)
and SI.LOGIN_TIME = (select max(LOGIN_TIME)from PA_LOGIN_SESSION_INFO SN where SI.LOGIN_ID=SN.LOGIN_ID)

Answer 1

Hi,
Without knowing your data, or the results you want from that data, I can't say for sure, but I'm guessing you want all the conditions to be outer join conditions. Using ANSI join syntax, you can do soemthing like this:
select
       PS.LNAME,
       PS.FNAME,
       SI.LOGIN_ID,
       PS.EMAIL_ADDR,
       US.col_num_20 Library_Type,
       US.col_num_30 Place_of_Work,
       US.col_num_10 Was_Rejected,
       US.col_num_70 Date_Created,
       PS.POSTAL,
       PS.STATE,
       DECODE (PS.NOTACTIVE, 'Y', 'N', 'Y') AS is_active, PS.NOTACTIVE,
       SI.LOGIN_TIME,
       SI.SEQ_NUM
from            PA_STUDENT          PS
left outer join       PV_STUD_USER           US     on     PS.STUD_ID     = US.STUD_ID      
left outer join       PA_LOGIN_SESSION_INFO SI     on      PS.STUD_ID     = SI.LOGIN_ID
                                        and      SI.LOGIN_TIME      = (
                                                    select  max (LOGIN_TIME)
                                                    from    PA_LOGIN_SESSION_INFO SN
                                                    where   SI.LOGIN_ID     = SN.LOGIN_ID
;Since you were using a + sign after a column from si in this condition:
and PS.STUD_ID = SI.LOGIN_ID (+)you must have a + sign in all conditions involving si; otherwise, the effect is an inner join.
Using the old join syntax (with + signs) you can't outer-join to a sub-query. If you really want to use the old syntax, re-write the condition involving si.login_time so that it doesn't join to a scalar sub-query (whihc might be more efficient anyway).
I hope this answers your question.
If not, post a little sample data (CREATE TABLE and INSERT statements, relevant columns only) for all tables involved, and also post the results you want from that data.
Explain, using specific examples, how you get those results from that data.
Always say which version of Oracle you're using.