[Gambas-user] Gambas2 components?

[Rob]

On Wednesday 14 January 2009 10:29, Gareth Bult wrote:
> This function would be required regardless of the underlying DB .. so
> what't the PG equivalent ?

By looking at the sqlite docs, I'm guessing last_insert_rowid() is their 
equivalent, but I only have MySQL installed so I can't test it.

But some DB engines don't even have auto-incrementing fields, let alone a 
function to return the last inserted ID.  Google tells me 

CURRVAL(pg_get_serial_sequence('my_tbl_name','id_col_name'))

is the Postgres equivalent, but if it uses sequences, I think that's 
different than what we know as autoincrement fields.  With Firebird, you 
can approximate the functionality with generators, like this:

-- before inserting any rows into table
CREATE GENERATOR generator_id;

-- then, as part of each insert statement
INSERT INTO tablename (keycolumn, ...) VALUES 
(gen_id(generator_id, 1), ...);

-- after all that, here's the LAST_INSERT_ID() equivalent
SELECT gen_id(generator_id, 0);

I have no idea whether this is safe to use with multiple connections (like 
MySQL's is) or anything like that.  I also don't think there's any 
standard ODBC mechanism to do this.

Rob