MySQL多表查询操作

MySQL操作单表增删改查和函数编写

一对多SQL表创建

-- 创建部门表(父表)
create table dept(
	id int auto_increment comment 'ID' primary key,
	name varchar(50) not null comment '部门名称'
) comment '部门表';

-- 给部门表插入数据
insert into dept (name) values ('研发部'),('市场部'),('财务部'),('销售部'),('总经办');


-- 创建员工表(子表)
create table emp(
	id int auto_increment comment 'ID' primary key,
	name varchar(50) not null comment '姓名',
	age int comment '年龄',
	job varchar(20) comment '职位',
	salary int comment '薪资',
	entrydate date comment '入职时间',
	managerid int comment '直属领导ID',
	dept_id int comment '部门ID',
	constraint fk_emp_dept_id foreign key (dept_id) references dept(id) 
)comment '员工表';

-- 向员工表添加数据
insert into emp (name,age,job,salary,entrydate,managerid,dept_id) values 
('金庸',66,'总裁',20000,'2000-01-01',null,5),
('张无忌',20,'项目经理',12500,'2005-12-05',1,1),
('杨逍',33,'开发',8400,'2000-11-03',2,1),
('韦一笑',48,'开发',11000,'2002-02-05',2,1),
('常遇春',43,'开发',10500,'2004-09-07',3,1),
('小昭',19,'程序员鼓励师',6600,'2004-10-12',2,1),
('灭绝',60,'财务总监',8500,'2002-09-07',1,3),
('周芷若',19,'会计',48000,'2006-06-02',7,3),
('丁敏君',23,'出纳',5250,'2009-05-13',7,3),
('赵敏',20,'市场部总监',12500,'2004-10-12',1,2),
('鹿杖客',56,'职员',3750,'2006-10-03',10,2),
('鹤笔翁',19,'职员',3750,'2007-05-09',10,2),
('方东白',19,'职员',5500,'2009-02-12',10,2),
('张三丰',88,'销售总监',14000,'2004-10-12',1,4),