行列遍历

Question

我的数据格式如下

id      idnew
 1       2
 3       4
 2       
 4       7
 6       8
 7

结果应该是这样的

ID后应加上idnew

 1
 2
 3
 4
 2
 4
 7
 6
 8
 7       


Thanks in advance

Answer 1

这应该保持顺序：

 SELECT id
   FROM (
        SELECT id, ROW_NUMBER() OVER (ORDER BY id) AS RowNumber
          FROM myTable
         UNION ALL
        SELECT idnew, ROW_NUMBER() OVER (ORDER BY idnew) + 
               (SELECT COUNT(*) FROM dbo.myTable) AS RowNumber
          FROM myTable
         WHERE idnew IS NOT NULL
        ) a
  ORDER BY RowNumber

我假设id列不可为空。

注意：如果要保留idnew列中的NULL值并保持顺序，请在第二个选择中删除WHERE子句和ORDER BY id：

 SELECT id
   FROM (
        SELECT id, ROW_NUMBER() OVER (ORDER BY id) AS RowNumber
          FROM myTable
         UNION ALL
        SELECT idnew, ROW_NUMBER() OVER (ORDER BY id) + 
               (SELECT COUNT(*) FROM dbo.myTable) AS RowNumber
          FROM myTable
        ) a
  ORDER BY RowNumber

Answer 2

这已经过全面测试，请在这里尝试：https://rextester.com/DVZXO21058

按照您所描述的那样设置表格：

Makefile

以下是完成此操作的查询：

   CREATE TABLE myTable (id INT, idnew INT);

   INSERT INTO myTable (id, idnew)
   VALUES (1, 2),
          (3, 4),
          (2, NULL),
          (4, 7),
          (6, 8),
          (7, NULL);

   SELECT * FROM myTable;

为了不进一步使查询复杂化，这是利用了'id'作为字符串优先于'idnew'的优势。我认为字符串排序不是这里的关键问题。

Answer 3

使用交叉申请

;WITH CTE (id,idnew)
AS
(
SELECT 1,2      UNION ALL
SELECT 3,4      UNION ALL
SELECT 2,NULL   UNION ALL
SELECT 4,7      UNION ALL
SELECT 6,8      UNION ALL
SELECT 7,NULL
)
SELECT New 
FROM CTE
CROSS APPLY ( VALUES (id),(idnew))AS Dt (New)
WHERE dt.New IS NOT NULL

结果

New
---
1
2
3
4
2
4
7
6
8
7