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[align=left]表结构如上图。表数据如下图。

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[align=left]创建触发器，使得：员工换工作（即员工的[font=Times New Roman]job_id[/font]改变）[font=Times New Roman],[/font]若该员工的[font=Times New Roman]job_lvl<[/font]他的新工作要求的[font=Times New Roman]min_lvl,[/font]则把他的[font=Times New Roman]job_lvl [/font]置为[font=Times New Roman] min_lvl[/font]；若该员工的[font=Times New Roman]job_lvl>[/font]他的新工作要求的[font=Times New Roman]max_lvl,[/font]则把他的[font=Times New Roman]job_lvl[/font]置为[font=Times New Roman]max_lvl.[/font]

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表的结构，刚才没发上去
create table employee(
emp_id char(9) primary key,
fname varchar(20) not null,
minit char(1),
lname varchar(30)not null,
job_id smallint not null,
job_lvl tinyint,
pub_id char(4) not null,
hire_date datetime not null
)
--drop table jobs
create table jobs(
job_id smallint primary key,
job_desc varchar(50),
min_lvl tinyint not null,
max_lvl tinyint not null
)
insert into employee
values('PMA42628M','Paolo','M','Accorti',13,35,'0877','1992-8-27')
insert into jobs values (1,null,10,10)
insert into jobs values (2,null,200,200)
insert into jobs values (3,null,175,175)
insert into jobs values (4,null,175,225)
insert into jobs values (5,null,150,250)
insert into jobs values (6,null,140,225)
insert into jobs values (7,null,120,200)
insert into jobs values (8,null,100,175)
insert into jobs values (9,null,75,175)
insert into jobs values (10,null,75,165)
insert into jobs values (11,null,75,150)
insert into jobs values (12,null,25,100)
insert into jobs values (13,null,25,100)
insert into jobs values (14,null,25,100)