Обсуждение: look up tables while parsing queries

Hi

I am modifying the source code. I want to look up some information
from some tables while parsing the queries. What functions I can use
to look up tables? btw I am using version 7.3. Thanks.

--
andrew

On Fri, 2006-02-03 at 10:46 +0100, andrew wrote:
> I am modifying the source code. I want to look up some information
> from some tables while parsing the queries.

If you're referring to the raw parser (parser/gram.y), you should not
attempt to access any tables. For one thing, the raw parser might be
invoked outside a transaction. The statement might also refer to a table
created earlier in the same query string, which would mean the
referenced table would not exist when the latter part of the query
string is parsed.

Instead, database access should be done in the analysis phase -- see
transformStmt() in parser/analyze.c and friends. There are plenty of
examples in the code of how to access tables, which should be a helpful
guide.

-Neil

On 2/5/06, Neil Conway <neilc@samurai.com> wrote:
> If you're referring to the raw parser (parser/gram.y), you should not
> attempt to access any tables. For one thing, the raw parser might be
> invoked outside a transaction. The statement might also refer to a table
> created earlier in the same query string, which would mean the
> referenced table would not exist when the latter part of the query
> string is parsed.
>
> Instead, database access should be done in the analysis phase -- see
> transformStmt() in parser/analyze.c and friends. There are plenty of
> examples in the code of how to access tables, which should be a helpful
> guide.
>
> -Neil

It is not in the raw parser. I meant inside the transformStmt(). What
is "friends"? Could  you possibly point out at least one place that
illustrates how to access  tables?

Thanks.

--
andrew