连接没有重复值的列

Question

你知道我如何连接这些列而不重复的值，假设我有一个表的结构(外部连接的结果):

ColumnA     ColumnB
--------------------
12345       null
69875       null
null        15648
76582       76582
null        29829
35731       35731

期望输出:

ColumnC
-------
12345       
69875      
15648       
76582       
29829       
35731       

Answer 1

这是我能想到的最好的方法

DECLARE @ColumnA TABLE (val INT)
INSERT INTO @ColumnA VALUES (12345)
INSERT INTO @ColumnA VALUES (69875)
INSERT INTO @ColumnA VALUES (NULL)
INSERT INTO @ColumnA VALUES (76582)
INSERT INTO @ColumnA VALUES (NULL)
INSERT INTO @ColumnA VALUES (35731)
DECLARE @ColumnB TABLE (val INT)
INSERT INTO @ColumnB VALUES (NULL)
INSERT INTO @ColumnB VALUES (NULL)
INSERT INTO @ColumnB VALUES (15648)
INSERT INTO @ColumnB VALUES (76582)
INSERT INTO @ColumnB VALUES (29829)
INSERT INTO @ColumnB VALUES (35731)
select
IIF (colA.val = colB.val, CAST(colA.val AS VARCHAR), ISNULL(CAST(colA.val AS VARCHAR), '') + ISNULL(CAST(colB.val AS VARCHAR), '')) concatenado
from (
SELECT ROW_NUMBER() OVER (ORDER BY (SELECT 1)) nro, val
FROM @ColumnA
) colA
JOIN (
SELECT ROW_NUMBER() OVER (ORDER BY (SELECT 1)) nro, val
FROM @ColumnB
) colB ON colA.nro = colB.nro