Question

嘿，我不知道怎么做......

它的作业：列出代码和仅购买“阿根廷”国家的汽车的消费者。

Table sell:

customer | resell  | veicle    |    date    |  value
---------+---------+-----------+------------+----------
 02      | 01      | 03        | 2010-02-05 | 17500.00
 04      | 02      | 01        | 2010-01-07 | 28000.00
 01      | 03      | 08        | 2010-02-15 | 28000.00
 02      | 03      | 02        | 2010-03-12 | 42000.00
 03      | 04      | 06        | 2010-02-06 | 11500.00
 03      | 02      | 05        | 2010-01-25 | 22100.00
 01      | 01      | 04        | 2010-01-21 | 15500.00

表客户：

 cod    |    name    | lastname
--------+------------+------------
 01     | Jose       | Alves
 02     | Paulo      | Cunha
 03     | Maria      | DPaula
 04     | Joana      | Silveria

表格：

 cod    |manufacturer|     model       | year |  country  |  price
--------+------------+-----------------+------+-----------+----------
 01     | 01         | Gol             | 2000 | Brasil    | 25000.00
 02     | 01         | Golf            | 2005 | Argentina | 39000.00
 03     | 04         | Ford Ka         | 1990 | Brasil    | 15000.00
 04     | 03         | Corsa Seda      | 1995 | Brasil    | 12500.00
 05     | 04         | Fiesta          | 2003 | Argentina | 20000.00
 06     | 03         | Corsa Seda      | 1995 | Argentina | 10000.00
 07     | 05         | Palio           | 2002 | Brasil    | 15000.00
 08     | 05         | Siena           | 2006 | Brasil    | 26000.00

我想要开始：

SELECT customer.cod, customer.name 
FROM sell, customer 
WHERE (SELECT cod 
        FROM veicle 
        WHERE veicle.country = 'Argentina') = sell.veicle;

只选择阿根廷汽车...... 请指导我回答。

Answer 1

SELECT c.*
FROM   customer c
WHERE EXISTS (
    SELECT 1
    FROM   sell s
    JOIN   veicle v ON v.cod = s.veicle
    WHERE  s.customer = c.cod
    AND    v.country = 'Argentina'
    )
AND NOT EXISTS (
    SELECT 1
    FROM ...
    );

我会把剩下的留给你，因为这是作业。填写...以排除购买非来自阿根廷的车辆的客户 - 与第一个EXISTS条款非常相似。如果你已经理解了第一个，你可以完成剩下的工作。

Answer 2

试试这个 SELECT DISTINCT customer.cod, customer.name || customer.lastname FROM customer, veicle, sell WHERE customer.cod = sell.customer AND veicle.cod = sell.veicle AND veicle.country = 'Argentina'

Answer 3

查看表连接。这样，你可以代替加入子查询（在你的where语句中），你可以加入表格（有点像你的From子句但你应该指定它加入的内容）然后在你可以放到的地方veicle.country ='阿根廷'。

并且FYI的面板拼写错误。它应该是车辆。

Answer 4

试试这个：

 SELECT c.cod, c.name,c.last_name,v.model
 FROM sell as s JOIN customer as c JOIN veicle as v ON s.veicle = v.cod and s.customer = c.cod
 WHERE v.country = 'Argentina'

Answer 5

WITH minima AS (
        SELECT DISTINCT s.customer
        , MIN(v.country) AS mi
        , MAX(v.country) AS ma
        FROM sell s
        JOIN veicle v ON s.resell = v.cod
        GROUP BY s.customer
        )
SELECT cu.* FROM customer cu
JOIN minima mm ON mm.customer = cu.cod
WHERE mm.mi = 'Argentina'
AND mm.ma = 'Argentina'
        ;

SQL，在表格中选择

5 个答案: