""Ivan Prenosil"" <prenosil@...> wrote in message
news:20020322115315.91F8D15002@......

> What I also do not understand is that I _can_ read temporary blob

Well, the blob exists somewhere. A UDF can push content in it. Whether it's
attached to a table doesn't matter. You attach it to a table's record to
make it permanent and just to have a way to recall the blob id from
somewhere. But the blob get/put/seek mechanism is rather independent of that
state.

> a) by using it in SP, e.g.
> CREATE PROCEDURE P RETURNS (B BLOB) AS BEGIN B=MyUDF(1); SUSPEND; END
>
> b) by using it in View, e.g.
> CREATE VIEW V (A,B) AS
> SELECT X, MyUDF(X) FROM T;
>
> but I _can't_ read it directly, like
>
> c) SELECT X, MyUDF(X) FROM T;
>
> What is the difference between selecting temporary blob from table
> and from view ? Is it as designed or is it a bug ?

The difference is probably that you weren't reading this forum when the same
bug was noticed more than a month ago. Then I suggested the use of
substring, after I patched the substring limitation that I discovered with
the same example. I think it's a DSQL bug only that means you can't select
directly from the UDF.

C.
--
Claudio Valderrama C. - http://www.cvalde.com - http://www.firebirdSql.org
Independent developer
Owner of the Interbase® WebRing