IF else inside case when statement

Question

Can we use IF ELSE condition inside CASE statement like below format

case when DATENAME(SECOND, GETDATE()) IN (N'Saturday', N'Sunday') 
        then if () then
              else if then 
           else 
          end,

    else 
    'Weekday'
 end

Answer 1

We can nest CASE expressions, or use multiple tests if appropriate.
These 2 example give the same result.

select 
  x,y,
  case 
    when x = 1 then
      case when y = 1 then 11
      else 12 
      end
    when x = 2 then
      case when y = 1 then 21
      else 22
      end
  else 99 end myExression
from test;

x	y	myexression
1	2	12
1	1	11
2	1	21
2	2	22
null	null	99

select 
  x,y,
  case
    when x = 1 and y = 1 then 11
    when x = 1 and y = 2 then 12
    when x = 2 and y = 1 then 21
    when x = 2 and y = 2 then 22
    else 99 
  end myExpression
from test;

x	y	myexpression
1	2	12
1	1	11
2	1	21
2	2	22
null	null	99

db<>fiddle here