postgresql - 选择两个表中的所有列

Question

假设我有以下内容:

表_a

| id |    date    | order_id | sku | price |
--------------------------------------------
| 10 | 2016-08-18 |    111   | ABC |   10  |

表_b

| id |    date    | order_id | description | type | notes | valid |
-------------------------------------------------------------------
| 50 | 2016-08-18 |    111   |     test    |  AA  |       | true  |

我想从两个表中获取所有列，因此结果表如下所示:

| id |    date    | order_id | sku | price | description | type | notes | valid |
---------------------------------------------------------------------------------
| 10 | 2016-08-18 |    111   | ABC |   10  |             |      |       |       |
---------------------------------------------------------------------------------
| 50 | 2016-08-18 |    111   |     |       |     test    |  AA  |       | true  |

我尝试过联合:

(
 SELECT *
 from table_a
 where table_a.date > Date('today')
)
UNION 
(
 SELECT *
 from table_b
 where table_b.date > Date('today')
)

但我得到一个:

ERROR: each UNION query must have the same number of columns

如何解决这个问题/是否有其他方法可以做到这一点？

Answer 1

或者，您可以直接加入它们，而不是 UNION:

SELECT  *
FROM    table_a A
JOIN    table_b B USING ( id )
WHERE   A.date > TIMESTAMP 'TODAY'
  AND   B.date > TIMESTAMP 'TODAY';

查看更多选项:https://www.postgresql.org/docs/9.5/static/queries-table-expressions.html#QUERIES-JOIN