I have a table, and I want to set all the cells in the row "State_Abbr" = "MN" How can I do this?
State_Abbr sounds like a field name. If that is the case then you will just need to do a simple sql update. You should be able to go into the query editor, switch to sql and then type in what is below. Remember to replace the section in brackets with your table name.
update [table name here] set state_abbr = "MN" where (state_abbr is null or state_abbr is not null)