On Sunday, January 7, 2018 at 12:07:13 AM UTC+1, Mike Bayer wrote:
>
> 1. will you always use sequences?
>
No, my dialect tries to use sequences only when the are explicitly
specified, otherwise it tries to use SERIAL. So:
Column('id', Integer, Sequence('some_id_seq'), primary_key=True) uses &
creates a sequence
Column('id', Integer, primary_key=True, autoincrement=True) uses SERIAL
2. are the sequences part of a database-side implicit system like PG
> SERIAL or SQL Server IDENTITY or do they need to be explicitly
> rendered like on Oracle?
>
They are both. Like in Postgresql you can have SERIAL which creates an
implicit sequence where I do not know the name for it. But I can also use
named sequences instead of a SERIAL column. What I cannot do is to set a
server side default value for columns with an explicit sequence to be
table_seq.NEXTVAL; I have to explicitly pass it in the query (Just like in
Oracle).
3. does your database support RETURNING?
>
No
4. does your database support some kind of "fetch last id" function
> that you run after an INSERT statement?
>
Yes, I can run "SELECT DBINFO('sqlca.sqlerrd1') FROM
sysmaster:"informix".sysdual" to retrieve the inserted serial after an
insert.
5. does your DBAPI provide #4 as cursor.lastrowid or not?
>
No
>From looking at the current test results, if I specify an explicit sequence
everything behaves properly as of now. Ie the dialect issue a "SELECT
seq.NEXTVAL FROM sysdual" and then uses that for inserts, the only thing
where it seems to fail currently is Integer primary key with autoincrement.
I'll look into mssql's ExecutinContext pre_exec/post_exec and
postfetch_lastrowid more extensively this evening. That said, I am happy
for every further advice.
Thank you for the long explanation!
Cheers,
Florian
>From
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