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. -- Simon Oliver
