Subject Re: [firebird-support] Re: generate report for POS
Author bill_lam
Adam wrote:
> For your report, simply start a snapshot transaction (not sure how
> this is done in your environment, but if you post details someone will
> know). Then just issue your select statement, and it will not see
> changes made subsequent to the transaction start. There are lots of
> options depending on what you are doing, and many scenarios that can
> be encountered, too many for a single post.
>
In ODBC, it uses four transaction isolation levels (as defined by SQL-92)
Read uncommitted
Read committed
Repeatable read
Serializable

SQLServer and MySQL ODBC support all 4 levels.
Firebird suport all except the first.

SNAPSHOT or versoning isolation levels are not mentioned in ODBC.

FYI, you are discouraged to issue a "SET TRANSACTION" sql command within ODBC,
because transactions must be managed using ODBC api. But I'll try to see if it
works.

BTW, is SNAPSHOT (transaction not cursor) available in other FB middleware like
jaybird or netprovider?

regards,
bill