Sql for update

Question

Hello All,
I am stuck in simple sql here hop you guys can help me.
Here is my scenerio
I have Table A,B,C
Table A
id,
package
Table B
id,
packageTable c
id
packageI need to update table A something like
update table A
set package = (select case when substr(b.package,1,3) = 'ABC' THEN CBA
                                       when substr(b.package,1,3) = 'EFD' THEN 'DFE'
                                       (now here is issue  i need to check for another package from other table C i am describing query in simple english)
                                                  if  substr(b.package,1,3) = 'ABC' then
                                                  if (c.package) = 'OO' then
                                                  package = 'OO'
                                                   else package = 'CBA'
                                           from B, c
                                           where b.id = c.id
                                             and   b.id = a.id)How i can fit this IF statment in to CASE, please guid.
Thanks a lot!

Answer 1

or
update table A
   set package = (select case when substr(b.package,1,3) = 'ABC'
                              then case when c.package = 'OO'
                                        then 'OO'
                                        else 'CBA'
                                   end
                              when substr(b.package,1,3) = 'EFD'
                              then 'DFE'
                         end
                    from B, c
                   where b.id = c.id
                     and b.id = a.id
                 )Regards
Etbin