显示订购的所有产品名称以及客户的名字和姓氏的列表
Show the list of all product's names ordered along with first and last names of the customers
我正在做一个练习,但我一直坚持下去。有 2 个表:
- 客户(身份证、名字、姓氏、地址)
- 订单(id,product_name,product_price,date_order 日期,id_customer,金额)
查询:
SELECT Orders.product_name, Customers.firstname, Customers.lastname
FROM Orders INNER JOIN
Customers
ON Orders.id_customer=Customers.id
ORDER BY Orders.id;
预期结果:
显示订购的所有产品名称以及客户姓名的列表。
仅在结果中包含那些在数据库中没有地址的客户,并按 Orders.id
对数据进行排序。
看起来你很接近。您只需要一个 WHERE
子句来满足此要求:
Include to the result only those customers who has no address in a database
试试这个:
SELECT Orders.product_name, Customers.firstname, Customers.lastname
FROM Orders INNER JOIN Customers ON Orders.id_customer = Customers.id
WHERE address IS NULL OR address = ''
ORDER BY Orders.id;
再添加一个地址为空的条件
SELECT Orders.product_name,
Customers.firstname,
Customers.lastname FROM Orders
INNER JOIN Customers ON
Orders.id_customer=Customers.id
and Customers.address IS NULL
ORDER BY Orders.id;
我正在做一个练习,但我一直坚持下去。有 2 个表:
- 客户(身份证、名字、姓氏、地址)
- 订单(id,product_name,product_price,date_order 日期,id_customer,金额)
查询:
SELECT Orders.product_name, Customers.firstname, Customers.lastname
FROM Orders INNER JOIN
Customers
ON Orders.id_customer=Customers.id
ORDER BY Orders.id;
预期结果:
显示订购的所有产品名称以及客户姓名的列表。
仅在结果中包含那些在数据库中没有地址的客户,并按 Orders.id
对数据进行排序。
看起来你很接近。您只需要一个 WHERE
子句来满足此要求:
Include to the result only those customers who has no address in a database
试试这个:
SELECT Orders.product_name, Customers.firstname, Customers.lastname
FROM Orders INNER JOIN Customers ON Orders.id_customer = Customers.id
WHERE address IS NULL OR address = ''
ORDER BY Orders.id;
再添加一个地址为空的条件
SELECT Orders.product_name,
Customers.firstname,
Customers.lastname FROM Orders
INNER JOIN Customers ON
Orders.id_customer=Customers.id
and Customers.address IS NULL
ORDER BY Orders.id;