Deprecate org.jooq.Clause

[lukaseder]

The VisitListener SPI is rather hard to implement correctly. One reason for this is that org.jooq.Clause is:

• Incompletely specified (e.g. some clauses are simply missing: Add org.jooq.Clause for transforming the LIMIT .. OFFSET clauses #3261, an issue open since 2014 and few people noticed!)
• Positioned randomly inside of QueryPart implementations (e.g. are there wrappers around expressions? How many? Etc.)

There has been a pending feature request to replace the Clause by actual QueryPart implementations: #3654, which is probably also not a good idea.

With this deprecation, we'll get feedback from users actually using the Clause, and we can better assess what to implement (if anything at all) in the future. The discussion will be open, and it might even include deprecating and removing the VisitListener SPI entirely. Discussion here: #7642

[matthewcachiaweavr]

Adding feedback as instructed in Clause.java's deprecation note.

Context:

• MySQL 8
• Micronaut 4 (jOOQ 3.19.7 comes bundled; version dictated by framework).
• Blanket Row-level Locking across all schemas which have a specific column (owner).
• A row is considered accessible if: owner is null or is equal to the subject accessing that piece of data.

The code snippet you provided in your article fits perfectly for my needs. At the same time I also agree that the visit listener with the current Clauses is really hard to work with.

Using an ExecutionListener(by tapping onto the context's query) proved much easier and works for the most part, except in certain "inline" situations where the query itself doesn't seem to be mutable. Take CTEs for example:

WITH
  cte1 AS (SELECT a, b FROM table1)
SELECT a, b FROM cte1

While I was able to access the inner query, I was unable to mutate it to become SELECT ... FROM table1 WHERE ownerId = ...). This forced me to revisit the VisitListener approach.

I would be happy to provide you the ExecutionListener approach, if you wish.

[lukaseder]

Agh, I meant to update that article a long time ago. Row level security are a feature in jOOQ now, since jOOQ 3.19:
https://www.jooq.org/doc/latest/manual/sql-building/queryparts/policies/

[lukaseder]

Ah, it's already mentioned in the middle, but not highlighted... I'll add it again at the top.