JOIN Issue : Correct the SQL Statement to solve : ORA-01799: a column may not be outer-joined to a subquery - sql

Question

As you see below; how can I implement fx.ftf_validitystartdate= ... this lines value since oracle does not allow me to do it like this below
.
select * from acc_accounts acc
join kp_paramcore p on
acc.account_no = p.accountnum
acc.suffix = p.suffixc
LEFT JOIN ftf_rates fx
ON p.maturestart = fx.ftf_vadealtsinir
AND p.maturefinish = fx.ftf_vadeustsinir
AND fx.statusrec = 'A'
AND fx.currencycode = acc.currencsw_kod
AND fx.status= 'A'
and fx.ftf_validitystartdate= (SELECT MAX(ff.ftf_validitystartdate)
FROM ftf_rates ff
WHERE ff.status = 'A'
AND ff.statusrec = 'A'
AND v_CurrentDate BETWEEN ff.systemstartdate AND ff.systemfinishdate AND ff.currencycode = acc.currencsw_kod
)

Answer 1

It should work if you switch this to a where clause:
select *
from acc_accounts acc join
kp_paramcore p
on acc.account_no = p.accountnum and
acc.suffix = p.suffixc LEFT JOIN
ftf_rates fx
ON p.maturestart = fx.ftf_vadealtsinir and
p.maturefinish = fx.ftf_vadeustsinir and
fx.statusrec = 'A' and
fx.currencycode = acc.currencsw_kod and
fx.status= 'A'
where fx.ftf_validitystartdate= (SELECT MAX(ff.ftf_validitystartdate)
FROM ftf_rates ff
WHERE ff.status = 'A' and
ff.statusrec = 'A'
p.v_CurrentDate BETWEEN ff.systemstartdate AND ff.systemfinishdate AND ff.currencycode = acc.currencsw_kod
)
However, you lose the 'left outer join' characteristics, so you would also want to add: or fx.ftf_validitystartdate is null. I guess that v_CurrentDate comes from "p". It is always a good idea to use table aliases before column names.
However, I question whether the subquery is really needed. It is only needed when there is more than one record that meets the conditions inside the subquery. Otherwise, I think you can just change the on clause to be:
ON p.maturestart = fx.ftf_vadealtsinir and
p.maturefinish = fx.ftf_vadeustsinir and
fx.statusrec = 'A' and
fx.currencycode = acc.currencsw_kod and
fx.status= 'A'and
p.v_CurrentDate BETWEEN fx.systemstartdate AND fx.systemfinishdate

Answer 2

I publish the workaround with CTE and tested only in Oracle 11g.
To make test I create this schema:
create table t_a ( a int );
create table t_b ( a int);
create table t_c ( a int);
insert into t_a values (1);
insert into t_a values (2);
insert into t_a values (3);
insert into t_b values (1);
insert into t_b values (2);
insert into t_b values (3);
insert into t_c values (1);
insert into t_c values (2);
insert into t_c values (3);
At this time I force error with this query:
select *
from t_a
left outer join t_b
on t_a.a = t_b.a and
t_b.a = ( select max( a )
from t_c);
And now I rewrite query with CTE:
with cte (a ) as (
select a
from t_b
where t_b.a = ( select min( a )
from t_c)
)
select *
from t_a
left outer join cte
on t_a.a = cte.a;
This second query returns right results.
I rewrite your query with CTE:
with CTE as (
select * from ftf_rates
where ftf_validitystartdate= (SELECT MAX(ff.ftf_validitystartdate)
FROM ftf_rates ff
WHERE ff.status = 'A'
AND ff.statusrec = 'A'
AND v_CurrentDate BETWEEN ff.systemstartdate
AND ff.systemfinishdate
AND ff.currencycode = acc.currencsw_kod )
)
select * from acc_accounts acc
join kp_paramcore p on
acc.account_no = p.accountnum
acc.suffix = p.suffixc
LEFT JOIN CTE fx
ON p.maturestart = fx.ftf_vadealtsinir
AND p.maturefinish = fx.ftf_vadeustsinir
AND fx.statusrec = 'A'
AND fx.currencycode = acc.currencsw_kod
AND fx.status= 'A'
Notice, only tested in Oracle 11g. See #a_horse_with_no_name coment:
#danihp: CTEs were available long before Oracle 11g (I think they were
introducted in 9.1 maybe even earlier - but they are definitely
available in 10.x). 11.2 introduced recursive CTEs which is not needed
in this case. –