题解 | #获取有奖金的员工相关信息。#

方法1：
SELECT emp_bonus.emp_no,employees.first_name,
employees.last_name,emp_bonus.btype,salaries.salary,
CASE emp_bonus.btype
WHEN 1 THEN salaries.salary0.1
WHEN 2 THEN salaries.salary0.2
WHEN 3 THEN salaries.salary*0.3
END AS bonus
FROM emp_bonus INNER JOIN employees INNER JOIN salaries
ON emp_bonus.emp_no=employees.emp_no
AND employees.emp_no=salaries.emp_no AND salaries.to_date='9999-01-01'

方法2：
SELECT emp_bonus.emp_no,employees.first_name,
employees.last_name,emp_bonus.btype,salaries.salary,
CASE
WHEN emp_bonus.btype=1 THEN salaries.salary0.1
WHEN emp_bonus.btype=2 THEN salaries.salary0.2
WHEN emp_bonus.btype=3 THEN salaries.salary*0.3
END AS bonus
FROM emp_bonus INNER JOIN employees INNER JOIN salaries
ON emp_bonus.emp_no=employees.emp_no
AND employees.emp_no=salaries.emp_no AND salaries.to_date='9999-01-01'
注意：
case语法：
CASE
WHEN condition1 THEN result1
WHEN condition2 THEN result2
WHEN conditionN THEN resultN
ELSE result
END;