Field (author.id) is not contained in Row when using without code generation

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Boris Heismann

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May 28, 2021, 2:48:18 PMMay 28
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Hi,

I'm evaluating jOOQ pro trial 3.14.11. I'm playing with it without to use code generator. Using fetch.intoMap("author.id") produces:
java.lang.IllegalArgumentException: Field (null) is not contained in Row ("author"."id", "author"."first_name", "author"."last_name", "book"."id", "book"."author_id", "book"."name", "book"."pubshing_date")

The RDBMS used is MariaDB. The piece of code is:
        SelectFinalStep<Record> select = dslContext.select()
                .from(table("author")
                        .join(table("book"))
                        .on(field("book.author_id")
                                .eq(field("author.id"))))
                .where(field("book.author_id")
                        .eq(1));
select.fetch().intoMap("author.id");

Using select.fetch().intoMap("id") generates a warning that field "id" is ambiguous because the table "book" uses it as well:
INFO: Ambiguous match found for id. Both "author"."id" and "book"."id" match.

What is the right proceeding here?

Best regards.

Boris


Lukas Eder

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May 28, 2021, 5:19:02 PMMay 28
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Hi Boris,

Thanks a lot for your message. Quick question first: Why are you not using the code generator? You will get a *much* better experience with jOOQ in general, if you're using the code generator. Omitting the code generator usually only makes sense when your schema is dynamic, and not known at compile time.

Meanwhile, regarding your particular issue, there's a common confusion between the plain SQL API (which you were using), and the API to construct references from identifiers (which you should be using).

See the relevant sections of the documentation here:

Or this blog post:

I hope this helps,
Lukas

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Boris Heismann

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May 30, 2021, 12:17:10 PMMay 30
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Hi Lukas,

Thank you very much for your explanation. Using name() helped a lot.

The reason to go with no code generator is the dynamic project structure. The objective is to develop an external tool to the already existing product which changes its schema often enough to make code generation pretty useless in this case. The product is designed in another programming language and is capable of using different DBs. So going with plain JDBC or something like Apache Derby isn't the choice.

Using name() I could overcome the complications I had with selects. However, now I'm on another point. I need to insert a number of records into two related tables. The tables are connected with the foreign key. I would like to do this covered into a transaction. In the example below authorRecord is null. This way I have no chance to find out the generated id for the author table. Can you please advise?


dslContext.transaction((configuration) -> {
                Record authorRecord = using(configuration)
                        .insertInto(table("author"), field("first_name"), field("last_name"))
                        .values("Evil", "Emerger")
                        .returning(field("id"))
                        .fetchOne();

                @NotNull Result<Record> bookRecord = using(configuration)
                        .insertInto(table("book"), field("author_id"), field("name"), field("publishing_date"))
                        .values(authorRecord.get(0), "Evolution of SQL", 2010)
                        .returning()
                        .fetch();

}
.......

Best regards,

Boris




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Rob Sargent

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May 30, 2021, 3:36:19 PMMay 30
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Hm. You're writing Java against the current DDL.  Code generation is nearly instantaneous so it’s trivial to keep it up to date with the target database. Include  run the code gen once you have set your DDL (and when you change it again)and have your IDE tell you the current table and column names. Don’t check in the generated code. 

It’s easy to tie DDL changes to code regeneration 


On May 30, 2021, at 10:17 AM, Boris Heismann <boris.h...@gmail.com> wrote:



Boris Heismann

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May 30, 2021, 3:59:41 PMMay 30
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@Robjs: this might be the case. However, I'm trying to evaluate the no-generated-code approach to identify both pros and cons.

Best regards,

Boris

Lukas Eder

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May 31, 2021, 4:26:04 PMMay 31
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Hi Boris,

 

I’m trying to get a more accurate understanding of “schema changing often enough” – because the way you described your examples, it seems that your code is wired against specific schema versions, not generic database models, in case of which I really suggest you look into coupling your data change management (e.g. via Flyway or Liquibase) to jOOQ’s code generation:

https://blog.jooq.org/2014/06/25/flyway-and-jooq-for-unbeatable-sql-development-productivity/

 

A lot of folks are doing that even with several database increments per day – this is not extraordinary. If your schema isn’t completely dynamic (but then, you won’t have field("first_name") in your code, because you wouldn’t know about "first_name" fields), then not using the code generation has mostly cons. You already ran into a few. It is common among new jOOQ users to see code generation as a “burden”, a step that is “hard” to get into existing CI pipelines (often because the pipelines may not be as formal as they could be). But if you think this through, you’ll see that you get two big wins:

 

 

Going back to your previous email. You were trying to use returning(field("id")) with plain SQL. There are some technical reasons why telling jOOQ the name of that field isn’t enough, if jOOQ doesn’t *know* that’s an identity column of your table("author"). This is just one more example where generated meta data would be helpful, i.e. in some dialects, this may not work, as you found out. I’m reluctant to walk you through workarounds – because… well that would work if you were using the code generator :)

 

I hope this helps,

Lukas

 

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