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From: SourceForge.net <no...@so...> - 2006-09-05 21:33:41
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Bugs item #1496014, was opened at 2006-05-27 16:42 Message generated for change (Comment added) made by nitwit You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=540672&aid=1496014&group_id=74338 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: MySQL Group: SQLObject release (specify) Status: Open Resolution: None Priority: 5 Submitted By: Neil Muller (nitwit) Assigned to: Nobody/Anonymous (nobody) Summary: None in enumValues fails Initial Comment: SQLObject-0.7.1b1 MySQL does not allow NULL inside the ENUM statemnt, so the construction EnumCol(enumValues=['a','b',None],default=None) will fail. Since this construction works fine with sqlite and postgresql, this is an issue. The attached patch fixes the problem here. ---------------------------------------------------------------------- >Comment By: Neil Muller (nitwit) Date: 2006-09-05 23:33 Message: Logged In: YES user_id=698097 The second issue only applies if a postgresql database is being accessed without using sqlobject as well. he check constraint approach used doesn't work as expected for postgresql. EnumCol(enumValues=['a','b',None],default=None) produces something like: create table t (c1 varchar(2) check (c1 in ('a','b',NULL))); However: insert into t values ('1'); will succeed, because of how postgresql interprets conditions involving NULL, as discussed in the message I linked to. Similiar issues may arise with other databases. However, since the call succeeds, a documentation note is probably adequate. I've attached a possible patch to SQLObject.txt as enum_doc_patch, although this probably needs furtehr work. ---------------------------------------------------------------------- Comment By: Neil Muller (nitwit) Date: 2006-09-05 23:16 Message: Logged In: YES user_id=698097 I've unfortunately combined two issues here, and I'll agree that the second patch is incorrect. There is an actual bug here. The current sqlobject logic breaks on mysql: The construction: EnumCol(enumValues=['a','b',None],default=None) maps to CREATE TABLE t (c1 ENUM ('a','b',NULL)); which is not valid for MySQL, which wants NULL's for ENUM columns handled as NULL constraints. This makes using None in the EnumCol impossible for MySQL. The mysql_enum patch attached aims to create a suitable constraint if None is present EnumCol. ---------------------------------------------------------------------- Comment By: Oleg Broytmann (phd) Date: 2006-09-05 15:57 Message: Logged In: YES user_id=4799 This contradicts to Python philoshy "We all are grown-ups people". If you know None (NULL) in enums is such a bad idea - just dont use it. But forcibly remove it when the user clearly states "I want my Nones here" is too much. Instead of such removing write a documentation patch and clearly explain the caveats. ---------------------------------------------------------------------- Comment By: Neil Muller (nitwit) Date: 2006-05-29 22:39 Message: Logged In: YES user_id=698097 I was pointed at http://archives.postgresql.org/pgsql-sql/2004-12/msg00065.php, which illustrates that NULL in the check constraint approach used to implement EnumCol for postges and other databases behave in an unexpected way due to the three state logic SQL uses. Thus a believe this second patch, which excludes Nones from all the database backends should be prefferred. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=540672&aid=1496014&group_id=74338 |
