Re: Syntax checking DO blocks and ALTER TABLE statements?

On Tue, Feb 16, 2021 at 4:28 PM Tim Cross <theophilusx(at)gmail(dot)com> wrote:

>
> David G. Johnston <david(dot)g(dot)johnston(at)gmail(dot)com> writes:
>
> > On Tue, Feb 16, 2021 at 3:43 PM Ron <ronljohnsonjr(at)gmail(dot)com> wrote:
> >
> >>
> >> How does one go about syntax checking this?
> >>
> >> (There are 222 ALTER TABLE ADD FOREIGN KEY statements that I'm wrapping
> in
> >> similar DO blocks, and want to make sure the statements are clean.)
> >>
> >>
> > Begin a transaction, execute the DO, capture an error if there is one,
> > rollback the transaction.
> >
>
> As David points out, wrapping the whole thing in a transaction will at
> least guarantee it all succeeds or it is all rollled back. This can be
> frustrating if the statements are slow and there are a lot of them as it
> can result in a very tedious do-run-fix cycle.
>
>
I do presume that someone wanting to test their code in this manner would
be doing so in a test environment and an empty database. Which makes the
execution time very small.

I personally would also solve the "lot of them" problem by using dynamic
SQL, so one pretty much only has to test the code generator instead of all
the actual executions - which can simply be confirmed fairly quickly once
on a test database without the need for transactions.

David J.