On 05/26/2018 09:21 AM, Alexander Farber wrote:
Good evening,
I am struggling with the syntax, please help.
This query with a CTE works ok:
WITH
extract_letters AS (
SELECT
mid,
STRING_AGG(x->>'letter', '') AS letters
FROM (
SELECT
mid,
JSONB_ARRAY_ELEMENTS(tiles) AS x
FROM words_moves
WHERE action='play'
) z
GROUP BY mid)
SELECT * from extract_letters;
mid | letters
--------+---------
12 | АКЖОЛ
15 | ДМО
16 | ТО
20 | ШГА
21 | КТИ
22 | ВОЗ
24 | АКПОНК
But UPDATEing from the CTE does not -
WITH extract_letters AS (
SELECT
mid,
STRING_AGG(x->>'letter', '') AS letters
FROM (
SELECT
mid,
JSONB_ARRAY_ELEMENTS(tiles) AS x
FROM words_moves
WHERE action='play'
) z
GROUP BY mid)
UPDATE words_moves m
SET m.letters = el.letters
I would say the above is the problem:
https://www.postgresql.org/docs/10/static/sql-update.html
"column_name
The name of a column in the table named by table_name. The column
name can be qualified with a subfield name or array subscript, if
needed. Do not include the table's name in the specification of a target
column — for example, UPDATE table_name SET table_name.col = 1 is invalid.
"
So it should be:
SET letters = el.letters
FROM extract_letters el
WHERE m.mid = el.mid;
ERROR: 42703: column "m" of relation "words_moves" does not exist
LINE 14: SET m.letters = el.letters
^
Regards
Alex
--
Adrian Klaver
adrian.klaver@xxxxxxxxxxx
