Is there any way to simplyfy this sql using case when or any other condition

Question

Hi,
Please ca you advise me to simplyfy the given sql         
 SELECT  
       CASE 
         WHEN  AxleNo=1  and AxleType = 'OFFSIDE OUTER'
            THEN SIZE    
        END AS off_1st_size_txt_out,
CASE 
         WHEN  AxleNo=1  and AxleType = 'OFFSIDE OUTER'
            THEN make    
        END AS off_1st_make_txt_out,
CASE 
         WHEN  AxleNo=1  and AxleType = 'OFFSIDE OUTER'
            THEN pattern    
        END AS off_1st_pat_txt_out,
CASE
 WHEN  AxleNo=1  and AxleType = 'OFFSIDE OUTER'
            THEN TreadDepth1    
        END AS off_1st_size_out,
CASE
WHEN  AxleNo=1  and AxleType = 'OFFSIDE OUTER'
            THEN TreadDepth2    
        END AS off_1st_make_out,
CASE
WHEN  AxleNo=1  and AxleType = 'OFFSIDE OUTER'
            THEN TreadDepth3    
        END AS off_1st_pat_out,
--1st near side outer
CASE 
         WHEN  AxleNo=1  and AxleType = 'NEARSIDE OUTER'
            THEN SIZE    
        END AS near_1st_size_txt_out,
CASE 
         WHEN  AxleNo=1  and AxleType = 'NEARSIDE OUTER'
            THEN make    
        END AS near_1st_make_txt_out,
CASE 
         WHEN  AxleNo=1  and AxleType = 'NEARSIDE OUTER'
            THEN pattern    
        END AS near_1st_pat_txt_out,
CASE
 WHEN  AxleNo=1  and AxleType = 'NEARSIDE OUTER'
            THEN TreadDepth1    
        END AS near_1st_size_out,
CASE
WHEN  AxleNo=1  and AxleType = 'NEARSIDE OUTER'
            THEN TreadDepth2    
        END AS near_1st_make_out,
CASE
WHEN  AxleNo=1  and AxleType = 'NEARSIDE OUTER'
            THEN TreadDepth3    
        END AS near_1st_pat_out,
--2nd Offside Outer
       CASE 
         WHEN  AxleNo=2  and AxleType = 'OFFSIDE OUTER'
            THEN SIZE    
        END AS off_2nd_size_txt_out,
CASE 
         WHEN  AxleNo=2  and AxleType = 'OFFSIDE OUTER'
            THEN make    
        END AS off_2nd_make_txt_out,
CASE 
         WHEN  AxleNo=2  and AxleType = 'OFFSIDE OUTER'
            THEN pattern    
        END AS off_2nd_pat_txt_out,
CASE
 WHEN  AxleNo=2  and AxleType = 'OFFSIDE OUTER'
            THEN TreadDepth1    
        END AS off_2nd_size_out,
CASE
WHEN  AxleNo=2  and AxleType = 'OFFSIDE OUTER'
            THEN TreadDepth2    
        END AS off_2nd_make_out,
CASE
WHEN  AxleNo=1  and AxleType = 'OFFSIDE OUTER'
            THEN TreadDepth3    
        END AS off_2nd_pat_out
from my fleets
With Many Thanks
Pol
polachan

Answer 1

Hello, 
the same result ( maybe with records in slightly different order ), you can obtain using this code snippet.
SELECT   SIZE AS off_1st_size_txt_out,
  make AS off_1st_make_txt_out,
pattern AS off_1st_pat_txt_out,
TreadDepth1 AS off_1st_size_out,
TreadDepth2 AS off_1st_make_out,
TreadDepth3 AS off_1st_pat_out,
NULL AS near_1st_size_txt_out,
  NULL AS near_1st_make_txt_out,
NULL AS near_1st_pat_txt_out,
NULL AS near_1st_size_out,
NULL AS near_1st_make_out,
NULL AS near_1st_pat_out,
NULL AS off_2nd_size_txt_out,
  NULL AS off_2nd_make_txt_out,
NULL AS off_2nd_pat_txt_out,
NULL AS off_2nd_size_out,
NULL AS off_2nd_make_out,
NULL AS off_2nd_pat_out
WHERE AxleNo=1  and AxleType = 'OFFSIDE OUTER'
from my fleets
UNION
SELECT   NULL AS off_1st_size_txt_out,
  NULL AS off_1st_make_txt_out,
NULL AS off_1st_pat_txt_out,
NULL AS off_1st_size_out,
NULL AS off_1st_make_out,
NULL AS off_1st_pat_out,
SIZE AS near_1st_size_txt_out,
  make AS near_1st_make_txt_out,
pattern AS near_1st_pat_txt_out,
TreadDepth1 AS near_1st_size_out,
TreadDepth2 AS near_1st_make_out,
TreadDepth3 AS near_1st_pat_out,
NULL AS off_2nd_size_txt_out,
  NULL AS off_2nd_make_txt_out,
NULL AS off_2nd_pat_txt_out,
NULL AS off_2nd_size_out,
NULL AS off_2nd_make_out,
NULL AS off_2nd_pat_out
WHERE AxleNo=1  and AxleType = 'NEARSIDE OUTER'
from my fleets
UNION
SELECT   NULL AS off_1st_size_txt_out,
  NULL AS off_1st_make_txt_out,
NULL AS off_1st_pat_txt_out,
NULL AS off_1st_size_out,
NULL AS off_1st_make_out,
NULL AS off_1st_pat_out,
NULL AS near_1st_size_txt_out,
  NULL AS near_1st_make_txt_out,
NULL AS near_1st_pat_txt_out,
NULL AS near_1st_size_out,
NULL AS near_1st_make_out,
NULL AS near_1st_pat_out,
SIZE AS off_2nd_size_txt_out,
  make AS off_2nd_make_txt_out,
pattern AS off_2nd_pat_txt_out,
TreadDepth1 AS off_2nd_size_out,
TreadDepth2 AS off_2nd_make_out,
TreadDepth3 AS off_2nd_pat_out
WHERE AxleNo=2  and AxleType = 'OFFSIDE OUTER'
from my fleets
If you find it easier to understand and to maintain. The result is made using "UNION" .
Šimon