Numeric types in DBIish

[salortiz]

Numeric types in DBIish

[Skarsnik]

Not all drivers support different float numeric representation like SQLite.
But yes, it's probably a good idea.

[abraxxa]

My take on floats was to use the Perl 6 type which is the default when you write my $float = 4.85; which is Rat.
This has also the advantage of not having the usual float rounding errors.
Are there any downsides from your point of view which I've missed? Performance?

[salortiz]

@abraxxa if you write 'float' when you are thinking Rat is your business :-)

The real problem is that DBIish should support and handle well the data in a Data Base not necessarily designed to be Perl 6 specific.
If a DBA uses, for wherever reason IEEE-754 types, the program needs to handle them in a predictably way, for example if a field in my DB contains the DOUBLE 1e+287 I want to see 1e+287 and that operations with it run at native speed.

As DB systems are richer in types, the best option is to design DBIsh with plugable types conversions, not fixed ones.

[salortiz]

From c57a200 all drivers after prepare expose in $sth.column-types[$col], the known field types to be returned.
In the SQLite case, where the column type is dynamic (and NUMERIC don't exist), the user can set the desired type before row fetching.
See https://github.com/perl6/DBIish/blob/master/lib/DBIish/CommonTesting.pm6#L216 for an example.
This mechanism will be generalized and extended for other drivers.
So I'm closing this issue.

[abraxxa]

Salvador you rock! Thanks for pushing DBIish forward!