When running this query:
SELECT id,selected_placements
FROM app_data.content_cards
I get a table like this:
+----+-------------------------------+
| id | selected_placements |
+----+-------------------------------+
| 90 | {162,108,156,80,163,155,NULL} |
+----+-------------------------------+
| 91 | {} |
+----+-------------------------------+
What I want to do now is get this same information but with the arrays splitted into rows so I get a result like this:
+----+---------------------+
| id | selected_placements |
+----+---------------------+
| 90 | 162 |
+----+---------------------+
| 90 | 108 |
+----+---------------------+
| 90 | 156 |
+----+---------------------+
| 90 | 80 |
+----+---------------------+
| 90 | 163 |
+----+---------------------+
| 90 | 155 |
+----+---------------------+
As you can see I don't want to get rows with null value in "selected_placements".
I am using PostgreSQL 8.0.2.
Many thanks!
I would suggest that you upgrade your version of Postgres. All supported versions support unnest():
SELECT x.*
FROM (SELECT id, UNNEST(selected_placements) as selected_placement
FROM app_data.content_cards
) x
WHERE selected_placement IS NOT NULL;
In earlier versions, you can strive to pick them out one at a time. The following is tested and works, albeit in 9.5:
with content_cards as (
select 1 as id, array['a', 'b', 'c'] as selected_placements
)
SELECT id, selected_placements[num] as selected_placement
FROM (SELECT cc.*, generate_series(1, ccup.maxup) as num
FROM content_cards cc CROSS JOIN
(SELECT MAX(ARRAY_UPPER(cc.selected_placements, 1)) as maxup
FROM content_cards cc
) ccup
) x
WHERE selected_placements[num] IS NOT NULL;