[development] Do not let postgresql hold back great patches

[Larry Garfield]

On Monday 03 December 2007, adrian rossouw wrote:
> On 03 Dec 2007, at 6:38 AM, Larry Garfield wrote:
> > #3 is what I'm pushing for in the D7 database overhaul, within
> > reason.  How to
> > abstract everything without making the syntax insane or the
> > performance
> > terrible is what I'm currently trying to wrap my head around.  The
> > biggest
> > problem is field type handling, which I want to keep away from module
> > developers but varies greatly depending on the database.
>
> and the biggest issue here is date / time types.
>
> it's fscking crazy how different these are between databases.

Actually, that one I think I have a solution for, or the beginnings of one.  
In PHP 5, there is the DateTime class to represent a date/time in some 
timezone.  It's great, but not a proper value object.  Writing a value object 
around DateTime is easy, however, and I've already done one.  

So, each database driver defines internally its own format string to convert a 
DateTime/DateValue class into the string format it expects for a date/time 
stamp.  The database driver then detects the presence of an object as an 
argument to a query/prepared statement and formats it to its desired format, 
which is then inserted into the query.  That works for putting a date/time 
value into a query (be it insert, update, delete, or select).  For reading, I 
believe we can use schema API to check if a field is a timestamp field and 
then cast it back to a DateValue object.  What the performance implication of 
that is, though, I do not know.  It may be something that we just have to 
swallow if we want real database independence, along with always using an 
object to represent a date/time (which I think we should be doing anyway).

As for in-SQL operations on the date value, like MONTH() or YEAR() in MySQL?  
If someone has an idea for those that doesn't involve regexing every query I 
would dearly love to hear it. :-)

-- 
Larry Garfield			AIM: LOLG42
larry at garfieldtech.com		ICQ: 6817012

"If nature has made any one thing less susceptible than all others of 
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