How to assign aliases to multiple select statements - oracle

Question

My issue is the right join is not working, I am guessing due to aliases used.
I have commented the lines using -- to indicate the lines that most probably are causing the issue. If I run my Cross Join part of the code separately it works fine.
If I add the cross join as show below, and then do a right join with the table final_leg a I am receiving an error saying 'relation "k" does not exist'.
k is the alias I am using in the last select statement to call the CROSS join part of the table.
WITH final_leg AS(
SELECT y.*
FROM
(
SELECT
y.shipment_id,
y.route_id,
max(leg_sequence_id) max_leg_sequence_id
FROM posimorders.sc_execution_eu.o_detailed_routes_v2 y
group by
1,2
) AS x
INNER JOIN posimorders.sc_execution_eu.o_detailed_routes_v2 y
on x.route_id = y.route_id and x.shipment_id = y.shipment_id and y.leg_sequence_id = x.max_leg_sequence_id
),
dest_leg AS(
SELECT y.*
FROM
(
SELECT
y.shipment_id,
y.route_id,
min(leg_sequence_id) max_leg_sequence_id
FROM
posimorders.sc_execution_eu.o_detailed_routes_v2 y
LEFT JOIN warehouse_attributes w -- Joining to add origin country of origin FC
ON w.warehouse_id = y.leg_warehouse_id
group by
1,2
) x
INNER JOIN posimorders.sc_execution_eu.o_detailed_routes_v2 y
on x.route_id = y.route_id and x.shipment_id = y.shipment_id and y.leg_sequence_id = x.max_leg_sequence_id
),
list_legs_ds AS(
SELECT t1.*, t2.* FROM
(SELECT leg_warehouse_id, SUM(pck_count) AS total_packages
FROM posimorders.sc_execution_eu.o_detailed_routes_v2
WHERE trunc(cpt_date) between '2019-06-16' and '2019-06-22'
and leg_sequence_id = 0
and leg_warehouse_id not like 'X%'
and right(leg_warehouse_id,1) in ('1','2','3','4','5','6','7','8','9') --Only SC and not Airports
group by 1
having sum(pck_count) > 50000
) t1
CROSS JOIN
(select distinct leg_warehouse_id AS lm_ds , destination_country_code
from posimorders.sc_execution_eu.o_detailed_routes_v2
where trunc(cpt_date) BETWEEN '2019-06-16' and '2019-06-22'
and leg_ship_method LIKE 'AMZN_%_PRIME'
) t2
)
SELECT
a.route_warehouse_id,
--k.leg_warehouse_id leg_ware,
--k.leg_warehouse_id lm_ds,
from
final_leg a
inner join dest_leg b
on a.shipment_id = b.shipment_id and a.route_id = b.route_id
--RIGHT JOIN list_legs_ds k
--on a.leg_warehouse_id = k.leg_ware -- and a.leg_ship_method = k.last_ds

Answer 1

The issue is most likely because you haven't aliased the columns in your list_legs_ds subquery, meaning you have at least two columns with the same name.
This is a good example of why you shouldn't, in general, use select *... and why you should be explicit in the columns you're selecting. Try the following instead:
WITH final_leg AS
(SELECT y.*
FROM (SELECT y.shipment_id,
y.route_id,
MAX(leg_sequence_id) max_leg_sequence_id
FROM posimorders.sc_execution_eu.o_detailed_routes_v2 y
GROUP BY 1,
2) AS x
INNER JOIN posimorders.sc_execution_eu.o_detailed_routes_v2 y
ON x.route_id = y.route_id
AND x.shipment_id = y.shipment_id
AND y.leg_sequence_id = x.max_leg_sequence_id),
dest_leg AS
(SELECT y.*
FROM (SELECT y.shipment_id,
y.route_id,
MIN(leg_sequence_id) max_leg_sequence_id
FROM posimorders.sc_execution_eu.o_detailed_routes_v2 y
LEFT JOIN warehouse_attributes w -- Joining to add origin country of origin FC
ON w.warehouse_id = y.leg_warehouse_id
GROUP BY 1,
2) x
INNER JOIN posimorders.sc_execution_eu.o_detailed_routes_v2 y
ON x.route_id = y.route_id
AND x.shipment_id = y.shipment_id
AND y.leg_sequence_id = x.max_leg_sequence_id),
list_legs_ds AS
(SELECT t1.leg_warehouse_id AS leg_ware,
t1.total_packages,
t2.leg_warehouse_id AS last_ds,
t2.destination_country_code
FROM (SELECT leg_warehouse_id AS leg_ware,
SUM(pck_count) AS total_packages
FROM posimorders.sc_execution_eu.o_detailed_routes_v2
GROUP BY 1
HAVING SUM(pck_count) > 50000) t1
CROSS JOIN (SELECT DISTINCT leg_warehouse_id AS last_ds,
destination_country_code
FROM posimorders.sc_execution_eu.o_detailed_routes_v2) t2)
SELECT a.route_warehouse_id,
k.leg_ware,
k.last_ds lm_ds
-- should there be something to aggregate here?
FROM final_leg a
INNER JOIN dest_leg b
ON a.shipment_id = b.shipment_id
AND a.route_id = b.route_id
RIGHT JOIN list_legs_ds k
ON a.leg_warehouse_id = k.leg_ware -- and a.leg_ship_method = k.lm_ds
GROUP BY 1,
2,
3;