Question

我有一些表具有不同的列和值，但希望将它们合并/结合在一起

表格如下：

A
Datetime        ID  A   B   C   D
1/1/2018 00:00:00   1   11  22  33  44
2/1/2018 00:00:00   1   11  22  33  44
3/1/2018 00:00:00   1   11  22  33  44
4/1/2018 00:00:00   1   11  22  33  44
5/1/2018 00:00:00   1   11  22  33  44
6/1/2018 00:00:00   1   11  22  33  44


B
Datetime        ID  E   F   G   H
1/2/2018 00:00:00   2   101 212 313 414
2/2/2018 00:00:00   2   101 212 313 441
3/2/2018 00:00:00   2   101 212 313 414
4/2/2018 00:00:00   2   101 212 313 414
5/2/2018 00:00:00   2   101 212 313 441
6/2/2018 00:00:00   2   101 212 313 441


C
Datetime        ID  I   J   K   L
1/3/2018 00:00:00   3   11  22  33  44
2/3/2018 00:00:00   3   11  22  33  44
3/3/2018 00:00:00   3   11  22  33  44
4/3/2018 00:00:00   3   11  22  33  44
5/3/2018 00:00:00   3   11  22  33  44
6/3/2018 00:00:00   3   11  22  33  44

我希望我的决赛桌看起来像这样：

决赛A

Datetime        ID  A   B   C   D
1/1/2018 00:00:00   1   11  22  33  44
2/1/2018 00:00:00   1   11  22  33  44
3/1/2018 00:00:00   1   11  22  33  44
4/1/2018 00:00:00   1   11  22  33  44
5/1/2018 00:00:00   1   11  22  33  44
6/1/2018 00:00:00   1   11  22  33  44


B
Datetime        ID  E   F   G   H
1/2/2018 00:00:00   2   101 212 313 414
2/2/2018 00:00:00   2   101 212 313 441
3/2/2018 00:00:00   2   101 212 313 414
4/2/2018 00:00:00   2   101 212 313 414
5/2/2018 00:00:00   2   101 212 313 441
6/2/2018 00:00:00   2   101 212 313 441


C
Datetime        ID  I   J   K   L
1/3/2018 00:00:00   3   11  22  33  44
2/3/2018 00:00:00   3   11  22  33  44
3/3/2018 00:00:00   3   11  22  33  44
4/3/2018 00:00:00   3   11  22  33  44
5/3/2018 00:00:00   3   11  22  33  44
6/3/2018 00:00:00   3   11  22  33  44

最终

Datetime        ID  A   B   C   D   E   F   G   H   I   J   K   L
1/1/2018 00:00:00   1   11  22  33  44
2/1/2018 00:00:00   1   11  22  33  44
3/1/2018 00:00:00   1   11  22  33  44
4/1/2018 00:00:00   1   11  22  33  44
5/1/2018 00:00:00   1   11  22  33  44
6/1/2018 00:00:00   1   11  22  33  44
1/2/2018 00:00:00   2                   101 212 313 414
2/2/2018 00:00:00   2                   101 212 313 441
3/2/2018 00:00:00   2                   101 212 313 414
4/2/2018 00:00:00   2                   101 212 313 414
5/2/2018 00:00:00   2                   101 212 313 441
6/2/2018 00:00:00   2                   101 212 313 441
1/3/2018 00:00:00   3                                   11  22  33  44
2/3/2018 00:00:00   3                                   11  22  33  44
3/3/2018 00:00:00   3                                   11  22  33  44
4/3/2018 00:00:00   3                                   11  22  33  44
5/3/2018 00:00:00   3                                   11  22  33  44
6/3/2018 00:00:00   3                                   11  22  33  44

我想不出逻辑，因为每个表都有自己的列，但我希望按照上面的说明进行合并。

寻求建议。

Answer 1

我们可以通过联合查询来做到这一点：

SELECT Datetime, ID, A, B, C, D, NULL AS E, NULL AS F, NULL AS G, NULL AS H,
    NULL AS I, NULL AS J, NULL AS K, NULL AS L
FROM A
UNION ALL
SELECT Datetime, ID, NULL, NULL, NULL, NULL, E, F, G, H, NULL, NULL, NULL, NULL
FROM B
UNION ALL
SELECT Datetime, ID, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, I, J, K, L
FROM C
ORDER BY
    ID, Datetime;

Demo

注意：不需要重复列别名，该列别名出现在后续选择中的联合查询的第一个选择中。实际上，此类别名只会被忽略。

由于易于设置，因此在SQL Server中任意给出了演示，但是查询应该在几乎所有数据库上运行。

Answer 2

SELECT Datetime,ID,A,B,C,D,NULL AS E,NULL AS F,NULL AS G,NULL AS H,NULL AS I,NULL AS J,NULL AS K,NULL AS L
FROM TableA
UNION ALL
SELECT Datetime,ID,NULL AS A,NULL AS B,NULL AS C,NULL AS D, E,F,G,H,NULL AS I,NULL AS J,NULL AS K,NULL AS L
FROM TableB
UNION ALL
SELECT Datetime,ID,NULL AS A,NULL AS B,NULL AS C,NULL AS D,NULL AS AS E,NULL AS AS F,NULL AS G,NULL AS H,I,J,K,L
FROM TableC

Answer 3

使用UNION ALL：

select Datetime,ID,  A,   B,   C,   D,   null as E,  null as F,   null as G,   null as H,   null as I,   null as J,   null as K,   null as L from tableA
union all
select Datetime,ID, null,   null ,  null ,  null ,    E,   F,   G,   H,   null ,   null ,   null ,   null  from tableB
Union all
select Datetime,ID,  null ,   null ,   null ,   null ,   null ,  null ,   null ,   H,   I,   J,   K,   L from tableC

我可以合并或加入这些表格吗？

3 个答案:

Demo