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Postings from March 2000
On Mon, 20 Mar 2000 08:59:40 -0600 gbacon@itsc.uah.edu (Greg Bacon) wrote: * In message <MailDrop1.2d7j-PPC.1000320012616@perlfaq.com>, * "Joseph N. Hall" writes: * : * : Here, @cols needs to be ,-separated, $table and $col need one kind of * : interpolation, and $val needs another. It's certainly not unreasonable * : to assume that a future qs// could be smart enough to recognize this * : much SQL. * * Do DBI placeholders handle that sort of thing? How hard would it be to * extend them to do so? Then your only hurdle would be syntactical. Placeholders don't have any context-sensitive quoting aspect that I'm aware of at present. Adding enough to be useful might or might not be difficult. As long as the approach is basically pattern-matching and NOT parsing of the "SQL" (which varies radically from vendor to vendor), I think that would be manageable. Some sort of clever "rules dictionary" that says "array name to the right of select is expanded with commas," "array name inside VALUES() list is quoted and expanded with commas," etc. is one thing I think might work. This really doesn't have anything to do with Perl guts EXCEPT that it might be nice if the access to interpolative stringification that currently exists through overload were MUCH finer grained. So perhaps for "$a @b $c[$d]" you'd get three separate calls, each with * thing being interpolated (globref or value ref) * context/position in string * anything else relevant (?) Something like this based on the guts of Perl is very important, because only Perl knows how to parse the guts of a double-quoted string. Obviously this capability would be useful to many things other than something like embedded SQL. * What sorts of expectations are you finding? What sorts of complaints * do people have about using DBI? The OO syntax and the DSNs and the like are obstacles. In general the clients should rely more on environment variables and a non constructor oriented syntax would be less of a barrier. "Should" meaning if the point is to make DBI more accessible. It's already reasonably versatile, even if it basically lacks cursors and type integration. -joseph