db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Andrew McIntyre (JIRA)" <j...@apache.org>
Subject [jira] Commented: (DERBY-3944) CHECK constraints involving user-coded functions may return different results depending on who performs the trigging INSERT/UPDATE
Date Wed, 12 Nov 2008 20:25:44 GMT

    [ https://issues.apache.org/jira/browse/DERBY-3944?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12647041#action_12647041
] 

Andrew McIntyre commented on DERBY-3944:
----------------------------------------

I checked yesterday and contrary to the way the docs read, DB2 doesn't actually allow user
defined functions in SQL  in check constraints either. I suspect this may simply be an overlooked
corner in the SQL spec, since none of the major vendors support user-defined functions in
check constraints and built-in functions never need a schema qualifier.

> CHECK constraints involving user-coded functions may return different results depending
on who performs the trigging INSERT/UPDATE
> ----------------------------------------------------------------------------------------------------------------------------------
>
>                 Key: DERBY-3944
>                 URL: https://issues.apache.org/jira/browse/DERBY-3944
>             Project: Derby
>          Issue Type: Bug
>          Components: SQL
>    Affects Versions: 10.5.0.0
>            Reporter: Rick Hillegas
>
> When compiling a CHECK constraint on behalf of an INSERT/UPDATE statement, Derby uses
the current schema in order to resolve unqualified function names which appear in the CHECK
constraint. This means that the CHECK constraint may evaluate true for some users, false for
others, and for others the CHECK constraint may raise an error saying that Derby can't resolve
the function reference. This behavior violates the "retrospective determinacy" of CHECK constraints
as specified by part 2 of the ANSI/ISO standard:
> 1) section 11.9 (<check constraint definition>), syntax rule 5
> 2) same section, general rule 1
> 3) section 11.6 (<table constraint definition>), general rule 3
> 4) section 4.16 (Determinism)
> For more discussion, please see this email thread: http://www.nabble.com/Problem-with-CHECK-constraints-td20445344.html#a20445344
> The following script demonstrates this problem:
> connect 'jdbc:derby:derbyauth;create=true;user=test_dbo;password=test_dbopassword' as
test_dbo_conn;
> drop table t_bp_2;
> drop function f_fp_minus;
> create function f_fp_minus
> (
>     a int
> )
> returns int
> language java
> deterministic
> parameter style java
> no sql
> external name 'org.apache.derbyTesting.functionTests.tests.lang.GeneratedColumnsTest.minus'
> ;
> create table t_bp_2( a int, constraint t_bp_2_check check ( f_fp_minus( a ) < 0 )
);
> grant insert on t_bp_2 to public;
> insert into test_dbo.t_bp_2( a ) values ( 100 );
> connect 'jdbc:derby:derbyauth;create=true;user=janet;password=janetpassword' as janet_conn;
> insert into test_dbo.t_bp_2( a ) values ( 100 );

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


Mime
View raw message