Upgrade to 17.04 fails on Postgres 8

[Marcus Leonard]

Me again (https://bugs.launchpad.net/mahara/+bug/1517658).

Upgrading from 15.10.1 to mahara-17.04.2. (Postgres 8.4.)
Running upgrade.php, auth.webservice step results in "Failed to upgrade."

Apache error Log (xxxx = redacted):
----------------------------------
xxxx [DBG] da (lib/dml.php:157) postgres8 error: [-1: ERROR: function left(character varying, integer) does not exist at character 73, referer: xxxx
xxxx [DBG] da (lib/dml.php:157) HINT: No function matches the given name and argument types. You might need to add explicit type casts.] in adodb_throw(UPDATE "external_functions", referer: xxxx
----------------------------------

Looks like it's here:
auth/webservice/db/upgrade.php:518
--------------------------------------------------
execute_sql(
            "UPDATE {external_functions}
            SET
                component = LEFT(
                    component,
                    LENGTH(component) - {$length}
                )
            WHERE
                component <> 'webservice'
                AND RIGHT(
                    component,
                    {$length}
                ) = '{$oldtail}'
            "
        );
--------------------------------------------------

Apparently functions left() and right() appeared in pg 9.3.

Is there a workaround for this on pg8?

Cheers,
Marcus

[Kristina Hoeppner (kris-hoeppner)]

Mahara 17.04 requires Postgres 9.1 at minimum. Please upgrade. The Readme file has been fixed to mention the correct version (to be pushed out with next minor point release).