On Wed, Jan 09, 2002 at 09:57:27AM +0000, Simon Oliver wrote: > Jonathan Leffler wrote: > > > > Hmmmm, basically, I see what's going on. Informix only supports > > delimited identifiers if the environment variable DELIMIDENT is set when > > the connection is initiated, which will make this very difficult to > > handle. In the absence of DELIMIDENT, Informix allows both single > > quotes and double quotes to identify strings (an issue predating the SQL > > standards on the subject). So, although the method outlined by Tim is > > correct, it won't work usefully unless DELIMIDENT is set, and DELIMIDENT > > needs to be set prior to making the connection so it can't be handled > > when the quote_identifier method is called. So, it would be useful if > > there was a connection time attribute that could be set indicating that > > delimited identifiers will be used -- if that's available, DBD::Informix > > can set DELIMIDENT before creating the connection and then all will be > > fine. Without that, Informix won't be able to do much -- you'll simply > > get (at best) syntax errors and (at worst) misunderstood SQL. > > This was my original intention (look back through the archives and you'll see > a big discussion with Tim on that subject). Tim is not in favour of adding > new attributes to the DBI class. Instead, I suppose the Informix DBD will > need to determine the value of DELIMIDENT (in the case of Informix) during > connection and set an internal (to the DBD) attribute that the > quote_identifier method can query. > > Ideally there should be a method in the DBI spec to facilitate turning quoted > identifiers on and off, or setting the delimitor(s), say > "identifier_delimitor" for the sake of argument. This method would be in the > DBD. Executing the method without any parameters would return the current > value(s) (I make it plural because some DBMS's permit balanced delimitors like > []). > > Whether the DBD determines/sets this value on a per connection basis, when the > identifier_delimitor method is called or each time quoted_identifiers is > called would be up to the implementor of the DBD.
I'm not keen. I just don't see a need. The driver should know (or be able to work out for itself) if it should be quoting identifiers on any given connection. No application visible API is needed. (A middle-road approach might be to have an option to quote_identifier that says only quote the identifier if it needs it. If a database don't support quoting identifiers then either quoting or not-quoting an identifier that needs it will generate an error anyway.) Tim.
