Woes using UPDATE with a CTE in MySQL (MariaDB) - mysql

Question

I'm going crazy trying to get UPDATE to work with a CTE in MySQL.
Here's a simplified schema of sa_general_journal:
CREATE TABLE `sa_general_journal` (
`ID` int(10) unsigned NOT NULL AUTO_INCREMENT,
`Transaction_ID` int(10) unsigned DEFAULT NULL COMMENT 'NULL if not split, same as ID for split records',
`Date` timestamp NOT NULL DEFAULT current_timestamp(),
…
`Statement_s` int(10) unsigned DEFAULT NULL,
…
`Name` varchar(255) DEFAULT NULL,
…
PRIMARY KEY (`ID`),
…
) ENGINE=InnoDB AUTO_INCREMENT=25929 DEFAULT CHARSET=utf8;
Some records are "split," for example, a credit card statement amount might have a sales tax amount that is split out. In such cases, both parts of the split record have the same ID in the Transaction_ID field.
When records are imported in bulk, they can't refer to last_insert_ID in order to fill in the Transaction_ID field, thus the need to go clean these up afterward.
This was my first, naive attempt, which said I had an error near UPDATE. Well duh.
WITH cte AS (
SELECT
ID,
MIN(ID) OVER(PARTITION BY `Date`, `Name`, Statement_s) AS Trans,
Transaction_ID
FROM sa_general_journal
WHERE Transaction_ID = 0)
UPDATE cte
SET Transaction_ID = Trans
The CTE itself seems to work, as I can follow it with SELECT * FROM cte and get what I expected.
So I started searching StackOverflow, and discovered that CTEs are not updatable, but that you need to join them to what you want to update. "No problem!" I think, as I code this up:
WITH cte AS (
SELECT
ID,
MIN(ID) OVER(PARTITION BY `Date`, `Name`, Statement_s) AS Trans,
Transaction_ID
FROM sa_general_journal
WHERE Transaction_ID = 0)
UPDATE sa_general_journal gj, cte
SET gj.Transaction_ID = cte.Trans
WHERE gj.ID = cte.ID
No joy. Same error message.
My understanding is that in MySQL, you don't need a column list, but I did also try this using the column list (a, b, c), with the proper columns referenced in the UPDATE statement, but it still said I had a problem near UPDATE.
There are incredibly few examples of using UPDATE with WITH on the Internet! I found one, from Percona, which I used to create my attempt above, and then found another very similar example from MySQL itself.
Thanks in advance for any help offered!

Answer 1

CTE is a part of subquery definition, not a part of the whole query. The query must be specified after CTE. CTE cannot be used itself. So
UPDATE sa_general_journal gj
JOIN (WITH cte AS ( SELECT
ID,
MIN(ID) OVER(PARTITION BY `Date`, `Name`, Statement_s) AS Trans,
Transaction_ID
FROM sa_general_journal
WHERE Transaction_ID = 0)
SELECT * FROM cte) subquery ON gj.ID = subquery.ID
SET gj.Transaction_ID = subquery.Trans

Answer 2

CTEs work with UPDATE in MySQL 8, but not MariaDB 10.x.