[Firebird-devel] Success tracking dependencies

[Claudio V. C. <cv...@us...>]

Don't you hate when you nuke a procedure by deleting elements that it uses
but that aren't tracked? Please see this isql session:

SQL> drop external function f_strblob;
Statement failed, SQLCODE = -607

unsuccessful metadata update
-cannot delete
-UDF F_STRBLOB
-there are 1 dependencies

The engine now detects if some procedure is using the UDF before
un-declaring it. I also have in place code to check DROP GENERATOR, but
since it doesn't exist yet, I will emulate it with a hard delete:

SQL> delete from rdb$generators where rdb$generator_name = 'GEN_DEPEND';
SQL> commit;
Statement failed, SQLCODE = -607

unsuccessful metadata update
-cannot delete
-GENERATOR GEN_DEPEND
-there are 1 dependencies
SQL>

In the first case, I didn't have to commit since DDL is auto-committed by
default in isql. However, since I have to use DML to delete an entry in
rdb$generators, I had to commit explicity to activate DFW. You may be
interested in this small improvement, too:

SQL> create table wiki(a int, b double precision, c image);
Statement failed, SQLCODE = -607

Dynamic SQL Error
-SQL error code = -607
-Invalid command
-Specified domain or source column IMAGE does not exist
SQL>

The engine now tells you the name of the data type or domain that it doesn't
recognize.

Next logical step *seems* to spank the engine so when you are creating a
large procedure, the message FIELD NOT FOUND will tell you what's the field
it doesn't recognize. I hope it's possible to improve that error message.

C.
---------
Claudio Valderrama C.
Ingeniero en Informática - Consultor independiente
http://www.cvalde.com - http://firebird.sf.net