SQL's Fallthrough CASE Statement

Question

In C# we can write

switch(num)
{
  case 0:
  case 1: // do something; break;
  case 2:
  ............
  ...........
  case n: // do something break;
  default: //do something; break;
}

How can I achieve the similar kind of stuff in SQL SERVER ?

I am not talking about the simple way of writing CASE in SQL SERVER. I am talking about if I need to perform the same king of operation in 2 or more case's as what I showed in C# code snippet, how to do the similar kind of stuff in SQL's CASE?

EDIT:

I got some nice answers from here already. How can I convert the following

SELECT CASE 
         WHEN [A]= num THEN '-' ELSE '' END [A], 
         CASE WHEN [B]= num THEN '-' ELSE '' END [B], 
         CASE WHEN [C]= num THEN '-' ELSE '' END [C],
         CASE WHEN [D]= num THEN '-' ELSE '' END [D]

...into something like:

SELECT CASE WHEN [A], 
       CASE WHEN [B], 
       CASE WHEN [C], 
       CASE WHEN [D] = num THEN '-' ELSE '' END [A] or [B] or [C] or [D]

Actually I need this in a PIVOT query. Last night I solved the problem. But I am not convinced with this way of writing. Because everytime, I am doing the same thing. So is there any better way of presenting this?

Answer 1

Like this:

SELECT 
  CASE num
    WHEN 0 THEN ...
    WHEN 1 THEN ...
    ELSE ...
  END as SomeCol
FROM ...

Answer 2

SQL does support a CASE statement but it's not the same thing as the switch statement in high level languages like C# and Java. In a switch statement, you have the concept of fall-through where if a break statement is not encountered, the flow continues to the next case. In contrast, a SQL CASE statement behaves like a high level language's if(value==1){ ... }else if(value==2){ ... }else{ ... }.

Answer 3

You might be looking for this.

SELECT
      CASE 
         WHEN (num BETWEEN 0 AND 2) THEN 'Between 0 and 2'
         WHEN (num = 3) THEN '3'
         ELSE 'Something else'
      END
...

More information on CASE from MSDN.

Answer 4

Like C# SWITCH statement, SQL Server's CASE expression does not support fallthrough.

Notice the emphasis on expression - it's not to be used for control of flow, use what is listed here.