Question

我有两张表格相似的表格。 First Table是供应商，其他表是suppliers_contacts。有没有办法将两列合并为一个？

我的suppliers表格如下：

id | contacts_name   | email
-- | ------          | -------
1  | sujith          | sujith@sujith
2  | mark            | 
3  | naveen          | naveen@naveen

和supplier_contacts表，如下所示：

suppliers_id | name      | email
--           | ----      |
1            | sujith    | sujith1@sujith    
2            | user1     | user1@user1
2            | user2     | user2@user2
3            | naveen1   | naveen1@naveen1
3            | naveen    | naveen2@naveen

我希望得到这样的东西：

contacts_name | name      | email 
--            | ------    | ------- 
sujith        | sujith    | sujith@sujith
sujith        | sujith    | sujith1@sujith
user1         | user1     | user1@user1
user2         | user2     | user2@user2
naveen        |           | naveen@naveen
naveen1       | naveen1   | naveen1@naveen1
naveen        | naveen    | naveen2@naveen

所有电子邮件ID都应该来自两个表中的一列。

我尝试了以下查询：

SELECT
    suppliers.name, 
    supplier_contacts.name AS name1, 
    supplier_contacts.email AS sup_c_email 
FROM suppliers 
JOIN supplier_contacts 
    ON suppliers.id = supplier_contacts.suppliers_id

任何人都可以帮我这个吗？基本上我希望来自两个表的电子邮件都在一列下，也应该显示两个表中的contacts_name和name。如果任何名称或contacts_name为NULL也很好。

Answer 1

SELECT suppliers.name, supplier_contacts.name AS name1, supplier_contacts.email AS 
sup_c_email 
FROM supplier 
INNER JOIN suppliers_contacts 
ON suppliers.email = supplier_contacts.email

我希望这会对你有所帮助

Answer 2

我认为你要找的是全外连接

虽然它返回大的结果集。

好好阅读link

Answer 3

SELECT s.contacts_name，sc.name，sc.email
来自供应商的s JOIN suppliers_contacts as sc ON s.id = sc.suppliers_id

如需更多解释，请访问以下链接，希望您能从中获得帮助 https://www.tutorialspoint.com/mysql/mysql-using-joins.htm

Answer 4

您可以使用union作为案例，首先获取所有电子邮件的列表然后进行左连接与suppliers_contacts

select
  t.contacts_name,
  s.name,
  t.email
from (
  select contacts_name, email from suppliers where email is not null
  union
  select name, email from suppliers_contacts
) t
left join suppliers_contacts s on t.email = s.email 
order by t.contacts_name;

Demo

根据您的上一条评论我期待的结果集是电子邮件列表。它应该合并两个表中的电子邮件列表并显示在一列中，您只需使用union查询

select contacts_name, email from suppliers where email is not null
union
select name contacts_name, email from suppliers_contacts
order by contacts_name;

Demo

编辑 *我想显示两个表中包含每个表的contacts_name和名称的所有电子邮件地址。如果名称为NULL，则为罚款*

select
t.contacts_name,
sc.name supplier_contact_name,
s.contacts_name supplier_name,
t.email
from (
  select contacts_name, email from suppliers where email is not null
  union
  select name, email from suppliers_contacts
) t
left join suppliers_contacts sc on t.email = sc.email 
left join suppliers s on t.email = s.email 
order by t.contacts_name;

Demo

如何将两个表中的列合并为一个列输出

4 个答案: