add manufacturer to all items

Most of my products are from 1 manufacturer. Manufacturer info. was not entered originally. Is there a way to add a manufacturer to all items? or do I have to do it one by one?
Thanks

the easiest way i can think of is

1. create manufacturer in catalog>>manufacturers
2. login to you sql and see in manufactuers table to find the manufactuers_id for that particular manufactuers
3. run query UPDATE products SET manufactuers_id = 'ID'
   ** replace red texted ID to the id you found on step 2.

Thanks for the help worked great. After fixing manufactuers_id as shown below.

gaurav10feb:

the easiest way i can think of is

1. create manufacturer in catalog>>manufacturers
2. login to you sql and see in manufacturers table to find the manufacturers_id for that particular manufacturers
3. run query UPDATE products SET manufacturers_id = 'ID'
   ** replace red texted ID to the id you found on step 2.

Thanks again