ORDER BY with Case-Statement DESC

Question

• How to ORDER BY with a CASE-Statement
  • first group: null values in date-column Col1 sorted by date-column Col2 D

Answer 1

SELECT columns FROM tables 
WHERE condition 
ORDER BY      
   case when Table1.Col1 IS NULL then 0 else 1 end ASC      
   ,case when Table1.Col1 IS NULL then Table2.Col2 else Table1.Col1 end DESC

Answer 2

This should work - just make the first column 0 or 1 based on whether it's null or not:

SELECT columns FROM tables WHERE condition
ORDER BY 
    case 
        when Table1.Col1 IS NULL     then 0 
                                     else 1
    end,
    case
        when Table1.Col1 IS NULL     then Table1.Col2
                                     else Table1.Col1
    end