> (1) Select given range of rows (limit and/or top query)
> select LIMIT 30 10 * from customer;
> -> syntax error. I need to select a given range of rows. Im able to
> do this with hsqldb, postgre and mysql.

SELECT FIRST 10 SKIP 30 * FROM customer.

Ask in Firebird-Support if LIMIT 30 10 is SQL standard. If I'm not
wrong it will also not work with DB2.

> (2) Selection from derived table
> select tempA.* from (select code from customer where code='a') as tempA;
> -> syntax error. Example is a simplified version, but should use a
> on-the-fly derived table within 'from' block. Works on in mssql,
> hsqldb and oracle. Dont know about postgre and mysql.

Not supported in Firebird 1.5. Ask in Firebird-Support if there are
plans to support it in Firebird 2.0. Also check if you cannot rewrite
your query, in most cases this is possible.

> Then a batch queries give me troubles as well. I've figured it out
> already that it's not supported in FB. I mean, I want to run in one
> go:
> Insert Into customer values(123, 'abc', 'a');
> Insert Into customer values(345, 'cde', 'd');
> Insert Into log values('added customer 123');
> Insert Into log values('added customer 345');
> -> I must split this at _clientside_ and run one by one.

Yes, that can be considered as Firebird limitation.

Also, please ask such questions in
http://groups.yahoo.com/group/Firebird-Support group.

Roman