MySQL视图中如何使用IF和CASE语句

-- 判断数据表是否存在，存在则删除
DROP TABLE IF EXISTS tb_staff;
 
-- 创建数据表
CREATE TABLE IF NOT EXISTS tb_staff
( 
	id INT AUTO_INCREMENT PRIMARY KEY COMMENT '编号',
	NAME VARCHAR(50) NOT NULL COMMENT '姓名',
	sex INT COMMENT '性别（1：男；2：女；）',
	dept_code VARCHAR(10) COMMENT '部门编号',
	is_post BIT COMMENT '是否在职（0：否；1：是）'
) COMMENT = '员工信息表';

-- 新增数据
INSERT INTO tb_staff(NAME,sex,dept_code,is_post) VALUES('pan_junbiao的博客_01',1,'1001',1);
INSERT INTO tb_staff(NAME,sex,dept_code,is_post) VALUES('pan_junbiao的博客_02',2,'1002',1);
INSERT INTO tb_staff(NAME,sex,dept_code,is_post) VALUES('pan_junbiao的博客_03',1,'1003',0);
INSERT INTO tb_staff(NAME,sex,dept_code,is_post) VALUES('pan_junbiao的博客_04',1,'1001',1);
INSERT INTO tb_staff(NAME,sex,dept_code,is_post) VALUES('pan_junbiao的博客_05',2,'1008',1);
INSERT INTO tb_staff(NAME,sex,dept_code,is_post) VALUES('pan_junbiao的博客_06',1,'1001',0);
INSERT INTO tb_staff(NAME,sex,dept_code,is_post) VALUES('pan_junbiao的博客_07',2,'1002',1);
INSERT INTO tb_staff(NAME,sex,dept_code,is_post) VALUES('pan_junbiao的博客_08',1,'1003',0);
INSERT INTO tb_staff(NAME,sex,dept_code,is_post) VALUES('pan_junbiao的博客_09',1,'1001',1);
INSERT INTO tb_staff(NAME,sex,dept_code,is_post) VALUES('pan_junbiao的博客_10',2,'1008',0);

-- 创建视图
CREATE OR REPLACE VIEW view_staff
AS
	SELECT id 
	,NAME
	,IF(sex=1,'男','女') AS sex_name
	,CASE dept_code
		WHEN '1001' THEN '研发部'
		WHEN '1002' THEN '人事部'
		WHEN '1003' THEN '财务部'
		ELSE '其他'
	END AS dept_name
	,IF(is_post,'在职','离职') AS is_post_name
	FROM tb_staff
;