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

Answer 3

SELECT Column1, Column2, Column3, Column4,
  Column5 = LEN(COALESCE(LEFT(Column1,1),'')) 
          + LEN(COALESCE(LEFT(Column2,1),''))
          + LEN(COALESCE(LEFT(Column3,1),'')) 
          + LEN(COALESCE(LEFT(Column4,1),''))
 FROM dbo.YourTable;

演示：

DECLARE @x TABLE(a VARCHAR(32),b INT,c VARCHAR(32),d VARCHAR(32));

INSERT @x VALUES
('01',3023,NULL,'blat'),
('02',NULL, NULL,'blat'),
('03',5,NULL,'blat'),
('04',24,'bo','blat'),
(NULL, NULL, NULL, NULL);

SELECT a, b, c, d,
    LEN(COALESCE(LEFT(a,1),'')) 
  + LEN(COALESCE(LEFT(b,1),''))
  + LEN(COALESCE(LEFT(c,1),'')) 
  + LEN(COALESCE(LEFT(d,1),''))
 FROM @x;

每行中非空列的计数

3 个答案: