Re: Alternative to psql -c ?

James Le Cuirot <chewi(at)aura-online(dot)co(dot)uk> writes:
> This got me wondering what Rails uses. I dug into ActiveRecord and
> found that apart from the odd call to PQexec with hardcoded single
> statements, it uses PQsendQuery. The libpq docs state a few of the
> differences but don't mention whether PQsendQuery automatically creates
> a transaction like PQexec does. Please could you clarify this?

PG is not capable of executing queries that are not in transactions,
so yes, PQsendQuery will create a single-statement transaction if you
haven't sent BEGIN. However, there's a huge difference for the
purposes we're discussing here: PQsendQuery does not allow more than
one SQL command in the string. So most of this discussion is irrelevant
when you're going through that API.

regards, tom lane