So not cool... Invalid argument supplied for foreach()
I run a few Drupal sites and felt that it was time to start upgrading to v6.16 from v5.1.
I started a test run on one of my sites...
I backed up the database and content.
Set the theme to garland and even turned off most of the extra modules other than the core modules.
I then deleted the v5.1 files and copied over the new v6.1 files. I also replaced all of the modules with their newer updates. I did keep the settings.php.
I brought the site up and received the following error in summary:
Warning: Unknown column 'serialized' in 'field list' query: SELECT data, created, headers, expire, serialized FROM cache WHERE cid = 'variables' ...
I followed some tips and did the following:
ALTER TABLE cache
ADD serialized smallint(6) NOT NULL default '0';
I've clear the cache "DELETE FROM TABLE 'cache'
and have even rebuilt the cache
CREATE TABLE IF NOT EXISTS cache (
cid varchar(255) NOT NULL default '',
data longblob,
expire int(11) NOT NULL default '0',
created int(11) NOT NULL default '0',
headers text,
serialized smallint(6) NOT NULL default '0',
PRIMARY KEY (cid),
KEY expire (expire)
) ENGINE=MyISAM DEFAULT CHARSET=utf8
and have also restored the existing database to start the steps over again.