Hello Augustus. On Thu, Dec 04, 2014 at 03:38:14PM -0800, Augustus Saunders wrote: > Hi all, I have been unable to find a way to use some of the new > JSONB operators in Postgres 9.4 with DBIx::Class. A quick search > for JSONB on the email archive site didn't turn up any results, so > I thought I would ask. > > In particular, ?, ?&, and ?| are now operators, and we run into > problems with the DBI placeholder being ?.
As more people start using Postgres 9.4 and the JSON operators this is going to become a significant problem. > I read that putting single quotes around the question mark would > allow a literal question mark in DBI, but I can't seem to make this > work from DBIx::Class. It won't do what you want. Question marks in quotes are ignored by the DBI driver, but question marks in quotes won't work as JSON operators. > Can anybody tell me whether this is currently possible, if so how, > and if not what might be involved or where in the code to look? For code not using DBIx::Class the pg_placeholder_dollaronly attribute might work, see https://metacpan.org/pod/DBD::Pg#Placeholders For code using DBIx::Class the problem is more tricky. I'm pretty sure that SQL::Abstract and thus DBIx::Class only support question mark placeholders. That means it probably impossible to use expressions containing a question mark operator with SQL::Abstract/DBIx::Class. (Though I'd be delighted to be proven wrong.) So I think the DBI spec for placeholders needs to be extended to allow a way to 'escape' a question mark that the driver would otherwise treat as a placeholder. The obvious and natural approach would be to use a backslash before a question mark. The backslash would be removed by the driver before the statement is passed to the backend. $dbh->selectrow_array(q{ SELECT {"a":1, "b":2}'::jsonb ? 'b' }); # breaks $dbh->selectrow_array(q{ SELECT {"a":1, "b":2}'::jsonb \? 'b' }); # would work The key question is: what is the risk of any existing DBI SQL statements containing a question mark placeholder that's preceeded by a backslash? Can anyone think of realistic examples? (For ANY DBI driver or backend.) Tim.
