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Posted to derby-dev@db.apache.org by "Rick Hillegas (JIRA)" <ji...@apache.org> on 2014/07/11 20:00:11 UTC
[jira] [Updated] (DERBY-6659) The Reference Guide should state how
long a SET CONSTRAINTS command is good for
[ https://issues.apache.org/jira/browse/DERBY-6659?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Rick Hillegas updated DERBY-6659:
---------------------------------
Description:
A SET CONSTRAINTS command changes the state of a constraint only until the transaction ends (or another, overriding SET CONSTRAINTS command is issued). Once the transaction ends, the constraint reverts to the default behavior declared for it at CREATE/ALTER TABLE time. However, this behavior is not clear from the reference material on SET CONSTRAINTS: https://builds.apache.org/job/Derby-docs/lastSuccessfulBuild/artifact/trunk/out/ref/rrefsqljsetconstr.html
The following script shows this behavior:
{noformat}
connect 'jdbc:derby:memory:db;create=true' as conn1;
autocommit off;
create table tprim
(
keyCol int primary key
);
create table tref
(
refCol int,
constraint refcon foreign key( refCol ) references tprim( keyCol ) deferrable
);
insert into tprim( keyCol ) values ( 1 ), ( 2 ), ( 3 );
commit;
set constraints refcon deferred;
-- succeeds because we switched to deferred mode for this transaction
insert into tref( refCol ) values ( 4 );
rollback;
-- but fails the second time because the end of the previous transaction
-- reverted the refcon constraint to its default (immediate) mode
insert into tref( refCol ) values ( 4 );
{noformat}
was:
A SET CONSTRAINTS command changes the state of a constraint only until the transaction ends (or another, overriding SET CONSTRAINTS command is issued). Once the transaction ends, the constraint reverts to the default behavior declared for it at CREATE/ALTER TABLE time. However, this behavior is not clear from the reference material on SET CONSTRAINTS: https://builds.apache.org/job/Derby-docs/lastSuccessfulBuild/artifact/trunk/out/ref/rrefsqljsetconstr.html
The following script shows this behavior:
{noformat}
connect 'jdbc:derby:memory:db;create=true' as conn1;
autocommit off;
call syscs_util.syscs_set_database_property( 'derby.locks.waitTimeout', '5' );
commit;
create table tprim
(
keyCol int primary key
);
create table tref
(
refCol int,
constraint refcon foreign key( refCol ) references tprim( keyCol ) deferrable
);
insert into tprim( keyCol ) values ( 1 ), ( 2 ), ( 3 );
commit;
set constraints refcon deferred;
-- succeeds because we switched to deferred mode for this transaction
insert into tref( refCol ) values ( 4 );
rollback;
-- but fails the second time because the end of the previous transaction
-- reverted the refcon constraint to its default (immediate) mode
insert into tref( refCol ) values ( 4 );
{noformat}
> The Reference Guide should state how long a SET CONSTRAINTS command is good for
> -------------------------------------------------------------------------------
>
> Key: DERBY-6659
> URL: https://issues.apache.org/jira/browse/DERBY-6659
> Project: Derby
> Issue Type: Improvement
> Components: Documentation
> Affects Versions: 10.11.0.0
> Reporter: Rick Hillegas
>
> A SET CONSTRAINTS command changes the state of a constraint only until the transaction ends (or another, overriding SET CONSTRAINTS command is issued). Once the transaction ends, the constraint reverts to the default behavior declared for it at CREATE/ALTER TABLE time. However, this behavior is not clear from the reference material on SET CONSTRAINTS: https://builds.apache.org/job/Derby-docs/lastSuccessfulBuild/artifact/trunk/out/ref/rrefsqljsetconstr.html
> The following script shows this behavior:
> {noformat}
> connect 'jdbc:derby:memory:db;create=true' as conn1;
> autocommit off;
> create table tprim
> (
> keyCol int primary key
> );
> create table tref
> (
> refCol int,
> constraint refcon foreign key( refCol ) references tprim( keyCol ) deferrable
> );
> insert into tprim( keyCol ) values ( 1 ), ( 2 ), ( 3 );
> commit;
> set constraints refcon deferred;
> -- succeeds because we switched to deferred mode for this transaction
> insert into tref( refCol ) values ( 4 );
> rollback;
> -- but fails the second time because the end of the previous transaction
> -- reverted the refcon constraint to its default (immediate) mode
> insert into tref( refCol ) values ( 4 );
> {noformat}
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