每行中非空列的计数

Question

我有一个包含4列的表,在第5列中,我想存储前4个中有多少个非空列的计数.例如:

其中X是任何值:

Column1 | Column2 | Column3 | Column4 | Count
  X     |    X    |   NULL  |    X    |   3
 NULL   |   NULL  |    X    |    X    |   2
 NULL   |   NULL  |   NULL  |   NULL  |   0

Answer 1

select
    T.Column1,
    T.Column2,
    T.Column3,
    T.Column4,
    (
        select count(*)
        from (values (T.Column1), (T.Column2), (T.Column3), (T.Column4)) as v(col)
        where v.col is not null
    ) as Column5
from Table1 as T

Answer 2

SELECT   Column1,
         Column2,
         Column3,
         Column4,
         CASE WHEN Column1 IS NOT NULL THEN 1 ELSE 0 END + 
         CASE WHEN Column2 IS NOT NULL THEN 1 ELSE 0 END + 
         CASE WHEN Column3 IS NOT NULL THEN 1 ELSE 0 END + 
         CASE WHEN Column4 IS NOT NULL THEN 1 ELSE 0 END AS Column5
FROM     Table