Re: [SQLObject] boolean types & python 2.2.x

[Ian B. <ia...@co...>]

On Dec 6, 2003, at 3:55 PM, Greg Brown wrote:
> I've found a minor problem using boolean columns on Pythons that don't 
> have a builtin boolean type:
>
>   File "SQLObject/DBConnection.py", line 72, in _runWithConnection
>     val = meth(conn, *args)
>   File "SQLObject/DBConnection.py", line 457, in _queryInsertID
>     q = self._insertSQL(table, names, values)
>   File "SQLObject/DBConnection.py", line 154, in _insertSQL
>     ', '.join([self.sqlrepr(v) for v in values])))
>   File "SQLObject/DBConnection.py", line 365, in sqlrepr
>     return sqlrepr(v, self.dbName)
>   File "SQLObject/Converters.py", line 168, in sqlrepr
>     raise ValueError, "Unknown SQL builtin type: %s for %s" % \
> ValueError: Unknown SQL builtin type: <type 'instance'> for TRUE
>
> For Python 2.2, a BOOL class is being defined to simulate the 
> important behavior of 2.3's builtin 'bool' type.  The problem has to 
> do with how the BOOL is being added to the ConverterRegistry.  It's 
> being registered as:
>
> registerConverter(type(TRUE), BoolConverter)
>
> ...which is how the rest of the converters are being registered in 
> Converters.py.  This doesn't work because all the others are new-style 
> classes that can be discriminated by type(x) while BOOL is an 
> old-style class, and the type() of all old-style classes is 
> 'instance'.  Old-style classes are being correctly registered with the 
> ConverterRegistry in SQLBuilder.py, with only the Class object being 
> passed into registerConverter() instead of the type() of the class.
>
> It seems like the cleanest fix is to make BOOL a new-style class by 
> changing it's definition to:
>
> class BOOL(object):
>
> so that it can be registered in the same way as all other types in the 
> Converters.py module regardless of whether it's on Python 2.2 or 2.3.
>
> This is with SQLObject 0.5.1, by the way.

Yes, it sounds like it's an oversight, and I couldn't test it because I 
don't have any version of Python 2.2 where True and False aren't their 
own objects.

--
Ian Bicking | ia...@co... | http://blog.ianbicking.org