SQL multiple-select case statement

Question

I can do something like this:

select 
case a.x > 1 then a.bananas else a.pajamas end 
from my_table a;

But when I try to tweak it like this:

select 
case a.x > 1 then a.bananas, a.pajamas else a.strawberries, a.peaches end 
from my_table;

it says I have an error in my syntax. How can I select arbitrary different subsets of my columns based on a condition?

Answer 1

You need a separate CASE for each column:

SELECT
    case a.x > 1 then a.bananas else a.pajamas end as bananas_or_pajamas,
    case a.x > 1 then a.strawberries else a.peaches end as strawberries_or_peaches,
    ....

Answer 2

CASE is a function, and can only return a single value. You can only use it to switch the value of one field in a query. Another option would be to wrap the whole query with an IF and have two separate queries to return results. Without seeing the rest of the query, it's hard to say if that would work for you.

Using case:

SELECT 

   result1 = CASE 
                  WHEN a.x > 1 THEN
                      a.bananas
                  ELSE
                     a.peaches
               END from my_table a,
   result2 = CASE
                  WHEN a.x > 1 THEN
                      a.pajamas
                  ELSE
                     a.strawberries
               END from my_table a

Answer 3

Try this code:

            SELECT 
               CASE 
                  WHEN a.x > 1 THEN
                      a.bananas
                  ELSE
                     a.peaches
               END from my_table result1,
               CASE
                  WHEN a.x > 1 THEN
                      a.pajamas
                  ELSE
                     a.strawberries
               END from 
           my_table result2;