Sql 将一个字段等分为2

如何将表“t2”的“col”字段与a、b、c、d作为记录等分为两个相等的字段：Col1 a、b和Col2 c、d

表：t2

Col
A 
B
C
D

输出：

Col1 Col2
 A     C
 B     D

这就是我尝试过的：

SELECT a.col1, "" as col2
FROM (SELECT  Top 50 Percent Col as Col1 From t2 order by Col ASc) as a

Union all

SELECT "", b.col1
FROM (SELECT  top 50 Percent Col as Col1 From t2 order by Col Desc) as b

来自上面的输出：

col1    col2
a   
b   
         d
         c

我只能在Ms access中访问到目前为止的位置。非常感谢您的帮助

创建表“t2”

Create Table t2(Col  Char)

插入值

INSERT INTO t2 ([Col]) VALUES ("a")
INSERT INTO t2 ([Col]) VALUES ("b")
INSERT INTO t2 ([Col]) VALUES ("c")
INSERT INTO t2 ([Col]) VALUES ("d")

---

是的，如果您有顺序ID，则可以使用交叉表：

TRANSFORM 
    First(T.Col) AS Col
SELECT 
    ([ID]+1)\2 AS DualID
FROM 
    (SELECT ID, [ID] Mod 2 AS ColID, [Col]
    FROM YourTable) AS T
GROUP BY 
    ([ID]+1)\2
PIVOT 
    T.ColID;

---

古怪的问题。也许透视/交叉表查询是最好的方法。出于好奇，这是真实世界的问题吗？@Andre不，练习问题。完美。非常感谢。

SELECT A1.COL1 &  "-" & B1.COL1 AS PAIRS
FROM 
(SELECT TOP 50 PERCENT A.Col AS COL1 FROM t2 AS A ORDER BY A.Col ASC) AS A1 
INNER JOIN 
(SELECT TOP 50 PERCENT B.Col AS COL1 FROM t2 AS B ORDER BY B.Col DESC) AS B1 
ON A1.COL1 <> B1.COL1
WHERE  (SELECT COUNT(*) FROM t2 AS C WHERE C.Col < A1.COL1) = (SELECT 
COUNT(*) FROM t2 AS D WHERE D.Col > B1.COL1)