Bug #18588 Triggers created in 5.0.20 can not be droped if downgrading to 5.0.15
Submitted: 28 Mar 2006 22:22 Modified: 8 Apr 2006 14:22
Reporter: Omer Barnir (OCA) Email Updates:
Status: Closed Impact on me:
None 
Category:MySQL Server Severity:S3 (Non-critical)
Version:5.0.20-bk OS:Linux (Linux - SuSe 9.3)
Assigned to:

[28 Mar 2006 22:22] Omer Barnir
Description:
This bug was found while writing tests for http://bugs.mysql.com/bug.php?id=15921

If a system is downgraded from current version (5.0.20) to 5.0.15, triggers created in 5.0.20 can not be dropped in 5.0.15.

How to repeat:
With 5.0.20
========
drop table if exists tbl1;
create table tbl1 (n1 int, s1 char(20));

set @test_var='In Upgrade: ';

create trigger trig1 before insert on tbl1
   for each row set @test_var=concat(@test_var,'_BI_');

# Checking the trigger is working
insert into tbl1 values (1, '2-new2-first');

select * from tbl1;
select @test_var;

===============
Downgrade the binaries to 5.0.15

After downgrade:
===============
# Check that the trigger still works
######################
set @test_var='In Downgrade: ';
insert into tbl1 values (2, 'second');
select * from tbl1;
select @test_var;

# Dropping triggers
#############
--error 1146
drop trigger db_test.trig1; <-- this is where the error happens
                                error 1146
                                and the trigger stays operational

Result file includes the following:
ERROR 42S02: Table 'db_test.ÿ±=^H^H<81>¤^H^H<81>¤^H' doesn't exist
[8 Apr 2006 14:22] Jon Stephens
Thank you for your bug report. This issue has been addressed in the
documentation. The updated documentation will appear on our website
shortly, and will be included in the next release of the relevant
product(s).

Additional info:

Updated DROP TRIGGER section of 5.0 Manual (updated warning deriving from Bug #15921 to include warning about this issue as well).