Question

This is my table.

What I need to do is create a CASE WHEN UPDATE Query to update

• CurrentCredit +1 if 1-15

• CurrentCredit +2 if 16-30

• CurrentCredit x.10 and round up if >=31

Answer 1

Have a look at the example

SQL Fiddle DEMO

Somethign like

UPDATE MyTable
SET CurrentCredit = 
CASE 
  WHEN CurrentCredit BETWEEN 1 AND 15
    THEN CurrentCredit + 1
  WHEN CurrentCredit BETWEEN 16 AND 30
    THEN CurrentCredit +2
  WHEN CurrentCredit >= 31
    THEN CurrentCredit * 10
  ELSE CurrentCredit
END

Also, remeber that if CurrentCredit is a FLOAT, and not an INT you might want to try something like

UPDATE MyTable
SET CurrentCredit = 
CASE 
  WHEN CurrentCredit >= 1 AND CurrentCredit < 16
    THEN CurrentCredit + 1
  WHEN CurrentCredit >= 16 AND CurrentCredit < 31
    THEN CurrentCredit +2
  WHEN CurrentCredit >= 31
    THEN CurrentCredit * 10
  ELSE CurrentCredit
END;

EDIT

For the corrected request (>= 31 CurrentCredit + CEILING(CurrentCredit * 0.1)) have a look at using CEILING

UPDATE MyTable
SET CurrentCredit = 
CASE 
  WHEN CurrentCredit BETWEEN 1 AND 15
    THEN CurrentCredit + 1
  WHEN CurrentCredit BETWEEN 16 AND 30
    THEN CurrentCredit +2
  WHEN CurrentCredit >= 31
    THEN CurrentCredit + CEILING(CurrentCredit * 0.1)
  ELSE CurrentCredit
END;

SQL Fiddle DEMO