[DB-SIG] paramstyles, again

[Carsten Haese]

On Thu, 2007-05-31 at 11:04 -0400, Michael Bayer wrote:
> numeric is redunant if you have named.  just name your params :1, : 
> 2, :3, etc.  OK, possibly you'd say then you have to send a dict  
> instead of a list, id just use a dict/enumerate combination on my  
> list for that.  whats the use case for numeric exactly ?

Backwards compatibility and performance. InformixDB has had numeric
style for much longer than it had named style, and it's cheaper to build
a parameter tuple than to build a parameter dict.

> >
> > I personally like named style, but I'm +0 on making it required. If it
> > were required, you'd have to specify how the API is expected to
> > differentiate between qmark and named. Do you expect the API to
> > auto-detect the parameter style from the query string, or do you  
> > expect
> > some kind of switching mechanism?
> 
> psycopg2, mysqldb, and pysqlite all support positional and non- 
> positional paramstyles right now (mysql/postgres do format and  
> pyformat, pysqlite does qmark and named), and they all know how to  
> automatically "switch" between the two categories.  im not sure if  
> they look at the string itself or the given args (my guess is they  
> look at the args being sent) but its totally doable.

I know auto-detect is doable, that's what InformixDB does. My point was
simply that you didn't specify your preference.

-- 
Carsten Haese
http://informixdb.sourceforge.net