How to change ACL group for all members?

Hi.

Background to the problem/request:
We are using Joomla 1.5 on our site, and a component called Community Builder Profile Pro that allows for havig different profile types with different profile pages, layouts etc. (possibly the same features in Joomla 2.5 although I haven´t updated myself on that issue in detail). We have recently opened up the site for registration of companies, which have different profile types than regular members. We would like the companies to have certain restrictions, so that they can read blog and forum posts but not be able to write there. We figured that the best way to accomplish this would be to let the companies have access rights (Joomla ACL group) as registered members and all regular member have access rights as authors. In that way we could set write access in the MyBlog and Kunena to authors, and thus get what we want.

And now to the problem:
At the beginning we had no idea of our future need in this regard, so all our soon to be 4000 regular members have access rights as registered members. We would need to upgrade all of our members (exept superadmin, the two admins and seven already registered companies) from registered to authors, and the question is: if this would be possible to do by some database query - instead of having to do this manually for the almost 4000 members?

Best regards -

if this would be possible to do by some database query

Nope. ACL on J1.5 involves about 4 database tables. A simply query won't do the trick and could cause serious problems if there's even a slight error in the query.

Really your only solution is to install an ACL manager extension (there's quite a few of these on JED). Aside from that manual updating of each user would have to do as J1.5 doesn't have Batch Processing like J2.5 does.