sql 表

1. staff表（.sql文件）

SET FOREIGN_KEY_CHECKS=0;

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– Table structure for staff

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DROP TABLE IF EXISTS staff;
CREATE TABLE staff (
staffId int(11) NOT NULL,
deptId int(11) DEFAULT NULL,
staffName varchar(255) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
salary decimal(10,2) DEFAULT NULL,
PRIMARY KEY (staffId)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

---

– Records of staff

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INSERT INTO staff VALUES (‘1’, ‘1’, ‘丽华’, ‘5000.00’);
INSERT INTO staff VALUES (‘2’, ‘1’, ‘TOM’, ‘7900.00’);
INSERT INTO staff VALUES (‘3’, ‘2’, ‘李雷’, ‘3500.00’);
INSERT INTO staff VALUES (‘4’, ‘2’, ‘韩梅梅’, ‘7900.00’);
INSERT INTO staff VALUES (‘5’, ‘3’, ‘jerr’, ‘15000.00’);
INSERT INTO staff VALUES (‘6’, ‘3’, ‘王小二’, ‘5800.00’);
INSERT INTO staff VALUES (‘7’, ‘1’, ‘李华’, ‘7900.00’);

2.department表（.sql文件）

SET FOREIGN_KEY_CHECKS=0;

---

– Table structure for department

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DROP TABLE IF EXISTS department;
CREATE TABLE department (
deptId int(11) NOT NULL,
areaId int(11) DEFAULT NULL,
deptName varchar(255) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
PRIMARY KEY (deptId)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

---

– Records of department

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INSERT INTO department VALUES (‘1’, ‘1’, ‘产品部’);
INSERT INTO department VALUES (‘2’, ‘1’, ‘销售部’);
INSERT INTO department VALUES (‘3’, ‘2’, ‘资金部’);

3.area表(.sql文件)

SET FOREIGN_KEY_CHECKS=0;

---

– Table structure for area

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DROP TABLE IF EXISTS area;
CREATE TABLE area (
areaId int(11) NOT NULL,
areaName varchar(255) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
PRIMARY KEY (areaId)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

---

– Records of area

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INSERT INTO area VALUES (‘1’, ‘上海’);
INSERT INTO area VALUES (‘2’, ‘郑州’);
INSERT INTO area VALUES (‘3’, ‘杭州’);

sql语句

查询各部门总工资最高的部门的工资最高的员工姓名，工资，所在区域，部门。
难点：
1.各部门总工资最高的可能有多个部门。
2. 员工工资最高的可能有多人。

select f.staffName as 姓名,f.salary as 工资,ar.areaName as 地区,d.deptName as 部门 from (
select st.deptId,st.staffName,st.salary from (
select c.* from (
select deptId,sum(salary) as sumsal,MAX(salary) as maxsal from staff s
Group by deptid
) c left join (
select deptId,max(sumsal) as maxsum from(
select deptId,sum(salary) as sumsal ,MAX(salary) as maxsal from staff s Group by deptid
) a
) b on c.sumsal=b.maxsum where c.sumsal=b.maxsum
) e left join staff st on st.deptId = e.deptId where st.deptId=e.deptId and st.salary=e.maxsal
)f left join department d on d.deptId=f.deptId
left join area ar on ar.areaId= d.areaId

查询效果