sql intersect 语句——迹忆客-ag捕鱼王app官网

sql intersect语句/运算符用于组合两个 select 语句，但仅返回两个select 语句结果集的交集。也就是第一个 select 语句中与第二个 select 语句中相同的行。

与 union 运算符一样，intersect 运算符具有相同的规则。mysql 不支持 intersect 运算符。

语法

intersect的基本语法如下。

select column1 [, column2 ]
from table1 [, table2 ]
[where condition]
intersect
select column1 [, column2 ]
from table1 [, table2 ]
[where condition]

示例

现在我们看如下的两张表

1. customers 表

 ---- ---------- ----- ----------- ---------- 
| id | name     | age | address   | salary   |
 ---- ---------- ----- ----------- ---------- 
|  1 | ramesh   |  32 | ahmedabad |  2000.00 |
|  2 | khilan   |  25 | delhi     |  1500.00 |
|  3 | kaushik  |  23 | kota      |  2000.00 |
|  4 | chaitali |  25 | mumbai    |  6500.00 |
|  5 | hardik   |  27 | bhopal    |  8500.00 |
|  6 | komal    |  22 | mp        |  4500.00 |
|  7 | muffy    |  24 | indore    | 10000.00 |
 ---- ---------- ----- ----------- ---------- 

2. orders 表

 ----- --------------------- ------------- -------- 
|oid  | date                | customer_id | amount |
 ----- --------------------- ------------- -------- 
| 102 | 2009-10-08 00:00:00 |           3 |   3000 |
| 100 | 2009-10-08 00:00:00 |           3 |   1500 |
| 101 | 2009-11-20 00:00:00 |           2 |   1560 |
| 103 | 2008-05-20 00:00:00 |           4 |   2060 |
 ----- --------------------- ------------- -------- 

现在，让我们在 select 语句中连接这两个表，如下所示。

sql> select  id, name, amount, date
   from customers
   left join orders
   on customers.id = orders.customer_id
intersect
   select  id, name, amount, date
   from customers
   right join orders
   on customers.id = orders.customer_id;

结果如下。

 ------ --------- -------- --------------------- 
| id   | name    | amount | date                |
 ------ --------- -------- --------------------- 
|    3 | kaushik |   3000 | 2009-10-08 00:00:00 |
|    3 | kaushik |   1500 | 2009-10-08 00:00:00 |
|    2 | ramesh  |   1560 | 2009-11-20 00:00:00 |
|    4 | kaushik |   2060 | 2008-05-20 00:00:00 |
 ------ --------- -------- ---------------------