[jira] [Updated] (DERBY-6383) dblook gives wrong column list for update trigger that references transition table

["Knut Anders Hatlen (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/DERBY-6383?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Knut Anders Hatlen updated DERBY-6383:
--------------------------------------

    Attachment: d6383.sql

This is actually more serious than dblook showing incorrect information. The trigger that was defined on update of column X does in fact fire on update of column Y as well. The attached script d6383.sql reproduces the bug:

{noformat}
ij> connect 'jdbc:derby:memory:db;create=true';
ij> create table t1(x int, y int);
0 rows inserted/updated/deleted
ij> create table t2(x int, y int);
0 rows inserted/updated/deleted
ij> insert into t1 values (1,2);
1 row inserted/updated/deleted
ij> -- create a trigger on update of T1(X)
create trigger t1 after update of x on t1 referencing old table as old insert into t2 select * from old;
0 rows inserted/updated/deleted
ij> -- update T1(Y), should not fire the trigger
update t1 set y = y + 1;
1 row inserted/updated/deleted
ij> -- trigger should not fire, so T2 should be empty
select * from t2;
X          |Y          
-----------------------
1          |2          

1 row selected
{noformat}

With 10.7.1.1 and earlier the final SELECT query returns no rows, which means the trigger had not fired. This is the correct behaviour, I believe.

With 10.7.1.4 and higher, the SELECT query returns one row (as seen above), which means the trigger had fired.

> dblook gives wrong column list for update trigger that references transition table
> ----------------------------------------------------------------------------------
>
>                 Key: DERBY-6383
>                 URL: https://issues.apache.org/jira/browse/DERBY-6383
>             Project: Derby
>          Issue Type: Bug
>          Components: SQL
>    Affects Versions: 10.7.1.4, 10.8.1.2, 10.9.1.0, 10.10.1.1
>            Reporter: Knut Anders Hatlen
>         Attachments: d6383.sql
>
>
> I see this problem on 10.8 and higher. To reproduce, create a database with a trigger like this:
> connect 'jdbc:derby:trigdb;create=true';
> create table t1(x int, y int);
> create table t2(x int, y int);
> create trigger tr after update of x on t1 referencing old table as old insert into t2 select * from old;
> Then run dblook on the database, and you'll see the following output:
> -- ----------------------------------------------
> -- DDL Statements for triggers
> -- ----------------------------------------------
> CREATE TRIGGER "APP"."TR" AFTER UPDATE OF "X", "Y" ON "APP"."T1" REFERENCING OLD_TABLE AS OLD FOR EACH STATEMENT insert into t2 select * from old;
> Notice that the DDL creates an update trigger for columns X and Y, whereas the original trigger was defined on column X only.
> I see the expected DDL on 10.7.1.1.



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