Re: [GENERAL] Support for idempotent schema changes?

[Florian G. Pflug]

Joshua D. Drake wrote:

David Lowe wrote:

Within the context of a script, executing:

Begin
Statement1
Statement2
Statement3
Commit

Where I only wish to commit if the error is specific to the object
already existing, and rollback for all other errors, what's the best way
to accomplish that?

You would have to put each statement into a savepoint, and catch each error that occured and commit or rollback to a savepoint

based on that result.

You could write a plpgsql function that executes a text given to it
as a parameter, and catches only "already exists" errors. Then your
schema script could look like
select execute_ignoreexists('create table ...') ;
select execute_ignoreexists('create index ...') ;
...

greetings, Florian Pflug

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