MySQL 基本語法 (十) UNION聯集

UNION聯集

1. 員工名字 UNION 客戶名字

SELECT `name`
FROM `employee`
UNION
SELECT `client_name`
FROM `client`;

2. 員工id + 員工名字 UNION 客戶id + 客戶名字

列出的表格名字會是第一個SELECT的屬性名稱，也可以使用AS將列出的屬性名稱做更改的動作

SELECT `emp_id`,`name`
FROM `employee`
UNION 
SELECT `client_id`,`client_name`
FROM `client`;

AS將列出的屬性名稱做更改的動作

SELECT `emp_id` AS `total_id`, `name` AS `total_name`
FROM `employee`
UNION 
SELECT `client_id`,`client_name`
FROM `client`;

3. 員工薪水 銷售金額

SELECT `salary`
FROM `employee`
UNION
SELECT `total_sales`
FROM `works_with`;

AS `total_money`

SELECT `salary` AS `total_money`
FROM `employee`
UNION
SELECT `total_sales`
FROM `works_with`;