我可以在一个查询中选择两个表吗？

Question

我有2张桌子

1. 费用
2. additional_fees

费用

fees id | fees_name | department | semester | hall_ticket | amount
--------------------------------------------------------------------
      1 |Tution Fees|    CSE     |    2-1   |     1234    | 10000

附加费用

fees id | fees_name | department | semester | add.amount
--------------------------------------------------------------------
      9 | Exam Fees |    CSE     |   2-1    | 5000

我想要这样

 fees_name | department | semester | hall_ticket | amount
---------------------------------------------------------
Tution Fees|    CSE     |    2-1   |     1234    | 10000
 Exam Fees |    CSE     |    2-1   |             | 5000

是否可以得到这样的结果？

Answer 1

使用UNION

select fees id , fees_name , department , semester , hall_ticket, amount from fees
union 
select fees id , fees_name , department , semester , null, add.amount from additionalfees

Answer 2

全部使用联盟

select fees_id,fees_name,department,semester,hall_ticket,amount from fees
union all
select fees_id,fees_name,department,semester,null,add.amount from additional_fees

Answer 3

是的，您可以使用UNION函数。

SELECT column_name(s) FROM table1
UNION
SELECT column_name(s) FROM table2;

Answer 4

最简单的方法是

  SELECT * FROM table1, table2;