Update script failes

I'm at a loss here, I tried to update my 4.6.x site to 4.7 but it doesn't
work and I know too little to even understand what's wrong.

When I run the update script I get a lot of error messages, it starts
like this (I've deleted the messages that were OK)

Update #110
DROP TABLE {search_index}
Failed: CREATE TABLE {search_total} ( word varchar(50) NOT NULL default '', count int(10) unsigned default NULL,
Failed: ALTER TABLE {blocks} DROP path
Failed: ALTER TABLE {blocks} ADD visibility tinyint(1) NOT NULL
Failed: ALTER TABLE {blocks} ADD pages text NOT NULL

Update #111
Failed: ALTER TABLE {sessions} ADD PRIMARY KEY sid (sid)

Update #112
Failed: CREATE TABLE {flood} ( event varchar(64) NOT NULL default '', hostname varchar(128) NOT NULL default '',
timestamp int(11) NOT NULL default '0' );

Update #113
Failed: ALTER TABLE {accesslog} ADD aid int(10) NOT NULL auto_increment, ADD PRIMARY KEY (aid)

Update #114
Failed: CREATE TABLE {queue} ( nid int(10) unsigned NOT NULL, uid int(10) unsigned NOT NULL, vote int(3) NOT
NULL default '0', PRIMARY KEY (nid, uid) )
Failed: ALTER TABLE {node} DROP votes
Failed: ALTER TABLE {node} DROP score
Failed: ALTER TABLE {node} DROP users

and it continues like this until update #128 which gives the last error message. After that everything seems to be OK.

Does anyone understand what's wrong and how I can fix it