[TYPO3-dev] Database compare and database modification inconsistencies

[Adrien Crivelli]

Hi,

I must confess I am one of those guy who don't see the point in DBAL.
However I try hard to follow the guidelines set by TYPO3 team.

Yet, I believe the example I wrote has nothing to do with DBAL. I don't
think any DBMS would let you create a field with a given structure but not
let another field to be modified to that very same structure. But I may be
mistaken... and if you could tell me which DBMS (and why) has such
limitations, that would definitely close the discussion.

I may have spoken a bit loudly when I said "SQL should be applied as it was
written" but I think the current mechanism is (slightly) broken and should
be fixed. Either using (slightly) less SQL rewriting, or by letting the
developer knows that the SQL he wrote is somewhat incompatible with TYPO3.


Adrien


On 3 January 2012 18:42, Jigal van Hemert <jigal at xs4all.nl> wrote:

> Hi,
>
>
> On 3-1-2012 9:46, Xavier Perseguers wrote:
>
>> Steffen Gebert wrote:
>>
>>> The database compare and database modification have inconsistencies which
>>>> are quite confusing. It's quite easy to write an ext_tables.sql which
>>>> will
>>>> be applied on database, but actually never show as "up do date" in
>>>> extension manager (so it seems it didn't apply). This is mostly
>>>> because of
>>>> limitation around "NOT NULL" and "DEFAULT" values.
>>>>
>>>
>>> Xavier, what's the opinion of the DBAL fraction?
>>>
>>
>> Just went through this post and the answer to "why SQL is rewritten" is
>> to be understandable and compatible with DBAL.
>>
>
> To expand on this a bit more: TYPO3 uses/supports a subset of SQL/MySQL.
> This is done to be able to support other DBMS than MySQL. DBAL adds some
> user functions to other DBMS so they can use some MySQL specific functions
> or rewrites queries which use those functions or constructions. Support for
> DBMS other than MySQL is quite important for an Enterprise level CMS.
> This imposes some limitations to the table structures you can use and the
> queries you can write, but these limitations do not make it impossible to
> implement the functionality you want.
>
> Unfortunately many extension developers don't see the need to produce DBAL
> compatible tables/queries.
>
> While the database compare routines could be improved I don't agree with
> the OP remark that SQL should be applied as it was written. It should be
> written according to the supported features.
>
> --
> Kind regards / met vriendelijke groet,
>
> Jigal van Hemert.
>
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