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最后两周/C语言同步练习答案.md
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最后两周/C语言同步练习答案.md
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最后两周/C语言基础进阶合集版编程题.md
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最后两周/C语言基础进阶合集版编程题.pdf
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最后两周/MySQL数据库操作综合练习题答案.md
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最后两周/MySQL数据库操作综合练习题答案.md
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### 练习一
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```sql
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#(1)创建数据库
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CREATE DATABASE test04_Market DEFAULT CHARACTER SET utf8;
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USE test04_Market;
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#(2)创建数据表
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CREATE TABLE customers(
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c_num INT(11) PRIMARY KEY AUTO_INCREMENT,
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c_name VARCHAR(50),
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c_contact VARCHAR(50),
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c_city VARCHAR(50),
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c_birth DATETIME NOT NULL
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);
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#(3)更改字段的位置
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#AFTER/BEFORE 字段名 设置位置在指定字段前/后
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ALTER TABLE 表名 MODIFY 字段名 数据类型 AFTER/BEFORE 字段名;
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ALTER TABLE customers MODIFY c_contact VARCHAR(50) AFTER c_birth;
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#(4)更改字段的数据类型
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ALTER TABLE customers MODIFY c_name VARCHAR(70);
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#(5)更改字段名
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ALTER TABLE customers CHANGE c_contact c_phone VARCHAR(50);
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#(6)添加字段
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ALTER TABLE customers ADD c_gender CHAR(1);
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#(7)更改表名
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ALTER TABLE customers RENAME TO customers_info;
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#(8)删除字段
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ALTER TABLE customers_info DROP c_city;
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```
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```sql
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#(1)创建表时 添加外键约束并指定外键约束名称
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CREATE TABLE orders(
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o_num INT(11) PRIMARY KEY AUTO_INCREMENT,
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o_date DATE,
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c_id INT(11),
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CONSTRAINT fk_cid FOREIGN KEY(c_id) REFERENCES customers_info(c_num)
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);
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#(2)
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#删除指定外键
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ALTER TABLE orders DROP FOREIGN KEY orders_ibfk_1;
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#删除指定表
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DROP TABLE orders;
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```
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---
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### 练习二
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```sql
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#(1)创建表、插入记录
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CREATE TABLE pet(
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`name` VARCHAR(20) NOT NULL COMMENT '宠物名称',
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`owner` VARCHAR(20) COMMENT '宠物主人',
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species VARCHAR(20) NOT NULL COMMENT '种类',
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sex CHAR(1) NOT NULL COMMENT '性别',
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birth YEAR NOT NULL COMMENT '出生日期',
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death YEAR COMMENT '死亡日期'
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);
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INSERT INTO pet()
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VALUES
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('Fluffy', 'Harold', 'cat', 'f', 2003, 2010),
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('Claws', 'Gwen', 'cat', 'm', 2004,NULL ),
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('Buffy', NULL, 'dog', 'f', 2009, NULL),
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('Fang', 'Benny', 'dog', 'm', 2000, NULL),
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('Bowser', 'Diane', 'dog', 'm', 2003, 2009),
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('Chirpy', NULL, 'bird', 'f', 2008, NULL);
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#(2)更新记录
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UPDATE pet
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SET `owner` = 'Kevin'
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WHERE `name` = 'Fang';
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#(3)
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UPDATE pet
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SET `owner` = 'Kevin'
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WHERE `owner` IS NULL;
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#(4)
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DELETE FROM pet
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WHERE death IS NOT NULL;
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#(5)
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TRUNCATE pet;
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```
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---
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### 练习三
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```sql
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#1.创建数据库
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CREATE DATABASE test_compay DEFAULT CHARACTER SET utf8;
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#2.创建表
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CREATE TABLE department(
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depid INT PRIMARY KEY AUTO_INCREMENT,
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depname VARCHAR(20) NOT NULL,
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deinfo VARCHAR(50)
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);
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CREATE TABLE employee(
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empid INT PRIMARY KEY AUTO_INCREMENT,
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`name` VARCHAR(20) NOT NULL,
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sex CHAR(1) NOT NULL DEFAULT '男',
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title VARCHAR(20) NOT NULL,
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birthday DATE NOT NULL,
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depid INT,
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CONSTRAINT fk_eid_did FOREIGN KEY(depid) REFERENCES department(depid)
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);
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CREATE TABLE salary(
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empid INT,
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basesalary DECIMAL(10, 2),
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titleSalary DECIMAL(10, 2),
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decuction DECIMAL(10, 2)
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);
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#3添加外键并设置级联更新、级联删除
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ALTER TABLE salary ADD CONSTRAINT fk_sal_eid FOREIGN KEY(empid)
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REFERENCES employee(empid) ON UPDATE CASCADE ON DELETE CASCADE;
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#4插入记录
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INSERT INTO department (depid, depname, deinfo)
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VALUES
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(111, '生产部', NULL),
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(222, '销售部', NULL),
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(333, '人事部', NULL),
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(444, '财务部', '负责公司财务管理'),
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(555, '技术部', '负责技术研发与支持'),
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(666, '市场部', '负责市场推广与品牌建设'),
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(777, '客服部', '负责客户服务与支持'),
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(888, '采购部', '负责公司物资采购'),
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(999, '法务部', '负责公司法律事务'),
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(1010, '行政部', '负责公司日常行政管理'),
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(1011, '研发部', '负责新产品研发'),
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(1012, '培训部', '负责员工培训与发展');
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INSERT INTO employee (empid, name, sex, title, birthday, depid)
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VALUES
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(1001, '张三', '男', '高级工程师', '1975-1-1', 111),
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(1002, '李四', '女', '助工', '1985-1-1', 111),
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(1003, '王五', '男', '工程师', '1978-11-11', 222),
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(1004, '赵六', '男', '工程师', '1999-1-1', 222),
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(1005, '陈七', '女', '会计师', '1980-5-15', 444),
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(1006, '刘八', '男', '软件工程师', '1990-8-20', 555),
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(1007, '孙九', '女', '市场经理', '1985-12-25', 666),
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(1008, '周十', '男', '客服专员', '1992-3-10', 777),
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(1009, '吴十一', '女', '采购经理', '1988-7-22', 888),
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(1010, '郑十二', '男', '法务顾问', '1983-9-30', 999),
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(1011, '王十三', '女', '行政助理', '1995-4-18', 1010),
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(1012, '李十四', '男', '研发工程师', '1991-11-5', 1011),
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(1013, '赵十五', '女', '培训讲师', '1987-6-12', 1012),
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(1014, '孙十六', '男', '技术支持', '1993-2-14', 555),
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(1015, '杨十七', '女', '销售代表', '1994-8-8', 222);
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INSERT INTO salary (empid, basesalary, titleSalary, decuction)
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VALUES
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(1001, 2200, 1100, 200),
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(1002, 1200, 200, NULL),
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(1003, 2900, 700, 200),
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(1004, 1950, 700, 150),
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(1005, 2500, 800, 100),
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(1006, 3000, 1200, 250),
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(1007, 2800, 1000, 200),
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(1008, 1800, 300, 50),
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(1009, 3200, 900, 300),
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(1010, 3500, 1000, 400),
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(1011, 2000, 400, 100),
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(1012, 3100, 1100, 200),
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(1013, 2700, 800, 150),
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(1014, 2300, 700, 100),
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(1015, 2600, 600, 200);
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```
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```sql
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#5
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SELECT e.empid, e.`name`, e.title, d.depname, s.basesalary + s.titleSalary, s.basesalary + s.titleSalary-IFNULL(s.decuction, 0)
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FROM employee e, department d, salary s
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WHERE e.depid = d.depid AND e.empid = s.empid;
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#6
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SELECT e.`name`, s.basesalary
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FROM employee e, department d, salary s
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WHERE e.depid = d.depid AND e.empid = s.empid AND d.depname = '销售部';
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#7
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SELECT *
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FROM employee e
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WHERe e.`name` LIKE '张%' AND TIMESTAMPDIFF(YEAR,e.birthday, NOW()) < 40;
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#8
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SELECT e.`name`, s.basesalary, s.titleSalary
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FROM employee e, salary s
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WHERE e.sex = '男' AND e.empid AND s.empid;
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#9
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SELECT e.`name`, e.title, d.depname
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FROM employee e, department d, salary s
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WHERE e.depid = d.depid AND e.empid = s.empid AND s.basesalary < 2000;
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#10
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SELECT COUNT(*)
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FROM employee;
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#11
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SELECT COUNT(*)
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FROM department d;
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#12
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SELECT AVG(s.basesalary + s.titleSalary), MAX(s.basesalary + s.titleSalary), MIN(s.basesalary + s.titleSalary)
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FROM employee e, salary s
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WHERE e.empid = s.empid;
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#13
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SELECT d.depname, AVG(s.basesalary + s.titleSalary)
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FROM employee e, salary s, department d
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WHERE e.empid = s.empid AND e.depid = d.depid
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GROUP BY d.depid;
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#14
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SELECT d.depname, AVG(s.basesalary + s.titleSalary) avg
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FROM employee e, salary s, department d
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WHERE e.empid = s.empid AND e.depid = d.depid
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GROUP BY d.depid
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HAVING avg<2000;
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#15
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SELECT e.empid, e.`name`, s.basesalary, s.titleSalary, s.decuction
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FROM employee e, salary s, department d
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WHERE e.empid = s.empid AND e.depid = d.depid
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ORDER BY s.titleSalary, s.basesalary;
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#16
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SELECT e.empid, e.`name`, e.birthday,
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IF(YEAR(e.birthday) < 1980, '老年',
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IF(YEAR(e.birthday)< 1990, '中年', '青壮年'))
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FROM employee e;
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#17
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SELECT e.*, depname
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FROM employee e, department d
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WHERE e.depid = d.depid;
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#18
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SELECT d.*, e.*
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FROM employee e, department d
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WHERE e.depid = d.depid;
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#19
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SELECT *
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FROM employee e
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WHERE e.title LIKE '%工程师%' AND e.sex = '男';
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#20
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SELECT d.depname, e.sex, COUNT(*), AVG(s.basesalary)
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FROM employee e, department d, salary s
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WHERE e.depid = d.depid AND e.empid = s.empid
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GROUP BY d.depid, e.sex;
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```
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---
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### 练习四
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|
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|
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|
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```sql
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#1
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CREATE DATABASE test_school DEFAULT CHARACTER SET 'UTF8';
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#2
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DROP TABLE department;
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CREATE TABLE department(
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depNo INT(10) PRIMARY KEY COMMENT '部门号',
|
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depName VARCHAR(50) NOT NULL COMMENT '部门名称',
|
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depNote VARCHAR(20) COMMENT '部门备注'
|
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);
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CREATE TABLE teacher(
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number INT PRIMARY KEY COMMENT '教工号',
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`name` VARCHAR(30) NOT NULL COMMENT '姓名',
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sex VARCHAR(4) COMMENT '性别',
|
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birth DATE COMMENT '出生日期',
|
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depNo INT COMMENT '部门号',
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salary FLOAT COMMENT '工资',
|
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address VARCHAR(100) COMMENT '家庭住址'
|
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);
|
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INSERT INTO department()
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VALUES
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(601, '软件技术系', '软件技术等专业'),
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(602, '网络技术系', '多媒体技术等专业'),
|
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(603, '艺术设计系', '广告艺术设计等专业'),
|
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(604, '管理工程系', '连锁经营管理等专业');
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|
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INSERT INTO teacher()
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VALUES
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(2001, 'Tom', '女', '1970-01-10', 602, 4500, '四川省绵阳市'),
|
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(2002, 'Lucy', '男', '1983-12-18', 601, 2500, '北京市昌平区'),
|
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(2003, 'Mike', '男', '1990-06-01', 604, 1500, '重庆市渝中区'),
|
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(2004, 'James', '女', '1980-10-20', 602, 3500, '四川省成都市'),
|
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(2005, 'Jack', '男', '1975-05-30', 603, 1200, '重庆市南岸区');
|
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```
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|
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|
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|
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```sql
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#4
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SELECT *
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FROM teacher;
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#5
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SELECT t.number '教工号', d.depName '部门名称'
|
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FROM teacher t, department d
|
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WHERE t.depNo = d.depNo AND t.address LIKE '%北京%';
|
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#6
|
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SELECT t.number, t.`name`
|
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FROM teacher t
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ORDER BY t.salary DESC
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LIMIT 1;
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#7
|
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SELECT t.number, t.`name`
|
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FROM teacher t
|
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WHERE t.salary BETWEEN 2500 AND 4000;
|
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#8
|
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SELECT t.`name`, t.sex, t.salary
|
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FROM teacher t, department d
|
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WHERE t.depNo = d.depNo AND d.depName = '网络技术系';
|
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```
|
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|
||||
---
|
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|
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### 练习五
|
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|
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|
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|
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```sql
|
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-- 创建数据库并设置字符集为 utf8mb4
|
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CREATE DATABASE test_student CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
|
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USE test_student;
|
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|
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-- 创建表 Classes
|
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CREATE TABLE Classes (
|
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专业 VARCHAR(50),
|
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班级 VARCHAR(50),
|
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姓名 VARCHAR(50),
|
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性别 VARCHAR(10),
|
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座位 INT
|
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);
|
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|
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-- 向表 Classes 插入数据
|
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INSERT INTO Classes (专业, 班级, 姓名, 性别, 座位) VALUES
|
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('计算机网络', '1班', '张三', '男', 8),
|
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('软件工程', '2班', '李四', '男', 12),
|
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('计算机维护', '1班', '王五', '男', 9),
|
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('计算机网络', '2班', 'LILY', '女', 15),
|
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('软件工程', '1班', '小强', '男', 20),
|
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('计算机维护', '1班', 'CoCo', '女', 18);
|
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|
||||
-- 创建表 Score
|
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CREATE TABLE Score (
|
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姓名 VARCHAR(50),
|
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英语 INT,
|
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数学 INT,
|
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语文 INT
|
||||
);
|
||||
|
||||
-- 向表 Score 插入数据
|
||||
INSERT INTO Score (姓名, 英语, 数学, 语文) VALUES
|
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('张三', 65, 75, 98),
|
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('李四', 87, 45, 86),
|
||||
('王五', 98, 85, 65),
|
||||
('LILY', 75, 86, 87),
|
||||
('小强', 85, 60, 58),
|
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('CoCo', 96, 87, 70);
|
||||
|
||||
-- 创建表 Records
|
||||
CREATE TABLE Records (
|
||||
姓名 VARCHAR(50),
|
||||
记录 VARCHAR(50)
|
||||
);
|
||||
|
||||
-- 向表 Records 插入数据
|
||||
INSERT INTO Records (姓名, 记录) VALUES
|
||||
('小强', '迟到'),
|
||||
('小强', '事假'),
|
||||
('李四', '旷课'),
|
||||
('李四', '旷课'),
|
||||
('李四', '迟到'),
|
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('CoCo', '病假'),
|
||||
('LILY', '事假');
|
||||
```
|
||||
|
||||
|
||||
|
||||
```sql
|
||||
#3
|
||||
UPDATE score s
|
||||
SET s.`语文` = 88
|
||||
WHERE s.`姓名` = '张三';
|
||||
|
||||
#4
|
||||
SELECT AVG(s.`英语`), AVG(s.`数学`), AVG(s.`语文`)
|
||||
FROM classes c, score s
|
||||
WHERE c.`姓名` = s.`姓名` AND c.`班级` = 1 AND c.`专业` = '计算机维护';
|
||||
|
||||
#5
|
||||
SELECT *
|
||||
FROM score s
|
||||
WHERE s.`数学` < 60 OR s.`英语` < 60 OR s.`语文` < 60;
|
||||
|
||||
#6
|
||||
SELECT *
|
||||
FROM score s
|
||||
WHERE s.`姓名` IN (
|
||||
SELECT r.`姓名`
|
||||
FROM records r
|
||||
GROUP BY r.`姓名`
|
||||
HAVING COUNT(*) > 2
|
||||
);
|
||||
```
|
||||
|
||||
---
|
||||
|
||||
### 练习六
|
||||
|
||||
|
||||
|
||||
```sql
|
||||
-- 创建数据库 test_xuankedb 并设置字符集为 utf8mb4
|
||||
CREATE DATABASE test_xuankedb CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
|
||||
USE test_xuankedb;
|
||||
|
||||
-- 创建学生表 Student
|
||||
CREATE TABLE Student (
|
||||
Sn0 VARCHAR(20) PRIMARY KEY, -- 学号，主键
|
||||
Sname VARCHAR(50), -- 姓名
|
||||
Ssex VARCHAR(10), -- 性别
|
||||
Sage INT, -- 年龄
|
||||
Sdept VARCHAR(50) -- 所在系
|
||||
);
|
||||
|
||||
-- 创建课程表 Course
|
||||
CREATE TABLE Course (
|
||||
Cn0 VARCHAR(20) PRIMARY KEY, -- 课程号，主键
|
||||
Cname VARCHAR(100), -- 课程名
|
||||
Cpn0 VARCHAR(20), -- 选修课号
|
||||
Ccredit INT -- 学分
|
||||
);
|
||||
|
||||
-- 创建成绩表 SG
|
||||
CREATE TABLE SG (
|
||||
Sn0 VARCHAR(20), -- 学号
|
||||
Cn0 VARCHAR(20), -- 课程号
|
||||
Grade INT, -- 成绩
|
||||
PRIMARY KEY (Sn0, Cn0), -- 复合主键 (学号, 课程号)
|
||||
FOREIGN KEY (Sn0) REFERENCES Student(Sn0), -- 外键，引用 Student 表
|
||||
FOREIGN KEY (Cn0) REFERENCES Course(Cn0) -- 外键，引用 Course 表
|
||||
);
|
||||
|
||||
INSERT INTO Student (Sno, Sname, Ssex, Sage, Sdept, Scome) VALUES
|
||||
('05001', '张三', '男', 20, '计算机系', '2021-09-01'),
|
||||
('05002', '李四', '女', 21, '数学系', '2021-09-01'),
|
||||
('05003', '王五', '男', 22, '计算机系', '2021-09-01'),
|
||||
('05004', '李洋', '男', 19, '物理系', '2021-09-01'),
|
||||
('05019', '赵六', '女', 20, '计算机系', '2021-09-01');
|
||||
|
||||
INSERT INTO Course (Cno, Cname, Cpno, Ccredit) VALUES
|
||||
('1', '数据库', NULL, 4),
|
||||
('2', '数学', NULL, 3),
|
||||
('3', '物理', NULL, 3),
|
||||
('4', '操作系统', '1', 4);
|
||||
|
||||
INSERT INTO SG (Sno, Cno, Grade) VALUES
|
||||
('05001', '1', 85),
|
||||
('05001', '2', 90),
|
||||
('05002', '1', 78),
|
||||
('05002', '3', 88),
|
||||
('05003', '1', 92),
|
||||
('05003', '4', 76),
|
||||
('05004', '3', 95),
|
||||
('05019', '1', 80),
|
||||
('05019', '4', 85);
|
||||
```
|
||||
|
||||
---
|
||||
|
||||
### 练习七
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
```sql
|
||||
-- 创建数据库 test_library 并设置字符集为 utf8mb4
|
||||
CREATE DATABASE test_library CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
|
||||
USE test_library;
|
||||
|
||||
-- 创建表 press（出版社）
|
||||
CREATE TABLE press (
|
||||
pressid INT PRIMARY KEY, -- 出版社编号，主键
|
||||
pressname VARCHAR(100), -- 出版社名称
|
||||
address VARCHAR(100) -- 出版社地址
|
||||
);
|
||||
|
||||
-- 创建表 sort（种类）
|
||||
CREATE TABLE sort (
|
||||
sortno INT PRIMARY KEY, -- 种类编号，主键
|
||||
scount INT, -- 数量
|
||||
describes VARCHAR(100) -- 描述
|
||||
);
|
||||
|
||||
-- 创建表 book（图书）
|
||||
CREATE TABLE book (
|
||||
bid INT PRIMARY KEY, -- 图书编号，主键
|
||||
bname VARCHAR(100), -- 图书名称
|
||||
bsortno INT, -- 种类编号
|
||||
pressid INT, -- 出版社编号
|
||||
FOREIGN KEY (bsortno) REFERENCES sort(sortno), -- 外键，引用 sort 表
|
||||
FOREIGN KEY (pressid) REFERENCES press(pressid) -- 外键，引用 press 表
|
||||
);
|
||||
|
||||
-- 向 press 表插入数据
|
||||
INSERT INTO press (pressid, pressname, address) VALUES
|
||||
(100, '外研社', '上海'),
|
||||
(101, '北大出版社', '北京'),
|
||||
(102, '教育出版社', '北京');
|
||||
|
||||
-- 向 sort 表插入数据
|
||||
INSERT INTO sort (sortno, scount, describes) VALUES
|
||||
(11, 50, '小说'),
|
||||
(12, 100, '科幻'),
|
||||
(13, 100, '神话');
|
||||
|
||||
-- 向 book 表插入数据
|
||||
INSERT INTO book (bid, bname, bsortno, pressid) VALUES
|
||||
(1, '红与黑', 11, 100),
|
||||
(2, '幻城', 12, 102),
|
||||
(3, '希腊神话', 13, 102);
|
||||
|
||||
#5
|
||||
SELECT b.*
|
||||
FROM book b, press p
|
||||
WHERE p.pressid = b.pressid AND p.pressid = 100;
|
||||
|
||||
#6
|
||||
SELECT b.*
|
||||
FROM book b, press p
|
||||
WHERE p.pressid = b.pressid AND p.pressname = '外研社';
|
||||
|
||||
#7
|
||||
SELECT *
|
||||
FROM sort s
|
||||
WHERE s.scount > 100;
|
||||
|
||||
#8
|
||||
SELECT p.*
|
||||
FROM book b, press p
|
||||
WHERE p.pressid = b.pressid
|
||||
GROUP BY b.pressid
|
||||
HAVING COUNT(*) = (
|
||||
SELECT COUNT(*)
|
||||
FROM book b, press p
|
||||
WHERE p.pressid = b.pressid
|
||||
GROUP BY b.pressid
|
||||
ORDER BY COUNT(*) DESC
|
||||
LIMIT 1
|
||||
);
|
||||
```
|
||||
|
||||
---
|
||||
|
||||
### 练习八
|
||||
|
||||
|
||||
|
||||
|
||||
|
||||
```sql
|
||||
-- 创建数据库 test_tour 并设置字符集为 utf8mb4
|
||||
CREATE DATABASE test_tour CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
|
||||
USE test_tour;
|
||||
|
||||
-- 创建表 agency（旅行社表）
|
||||
CREATE TABLE agency (
|
||||
id INT PRIMARY KEY, -- 旅行社编号，主键
|
||||
name VARCHAR(100) NOT NULL, -- 旅行社名
|
||||
address VARCHAR(100) NOT NULL, -- 旅行社地址
|
||||
areaid INT -- 所属区域编号
|
||||
);
|
||||
|
||||
-- 创建表 travel（旅行线路表）
|
||||
CREATE TABLE travel (
|
||||
tid INT PRIMARY KEY, -- 旅行线路编号，主键
|
||||
time VARCHAR(50) NOT NULL, -- 所需时间
|
||||
position VARCHAR(100) NOT NULL, -- 目的地
|
||||
money FLOAT, -- 花费
|
||||
aid INT NOT NULL, -- 所属旅行社编号
|
||||
count INT, -- 报名人数
|
||||
FOREIGN KEY (aid) REFERENCES agency(id) -- 外键，引用 agency 表
|
||||
);
|
||||
|
||||
-- 向 agency 表插入数据
|
||||
INSERT INTO agency (id, name, address) VALUES
|
||||
(101, '青年旅行社', '北京海淀'),
|
||||
(102, '天天旅行社', '天津海院');
|
||||
|
||||
-- 向 travel 表插入数据
|
||||
INSERT INTO travel (tid, time, position, money, aid, count) VALUES
|
||||
(1, '5天', '八达岭', 3000, 101, 10),
|
||||
(2, '7天', '水长城', 5000, 101, 14),
|
||||
(3, '8天', '水长城', 6000, 102, 11);
|
||||
|
||||
#4
|
||||
SELECT a.*
|
||||
FROM travel t, agency a
|
||||
WHERE t.aid =a.id
|
||||
GROUP BY a.id
|
||||
HAVING COUNT(*) = (
|
||||
SELECT COUNT(*)
|
||||
FROM travel t, agency a
|
||||
WHERE t.aid =a.id
|
||||
GROUP BY a.id
|
||||
ORDER BY COUNT(*) DESC
|
||||
LIMIT 1
|
||||
);
|
||||
|
||||
#5
|
||||
SELECT t.*
|
||||
FROM travel t
|
||||
WHERE t.count = (
|
||||
SELECT t.count
|
||||
FROM travel t
|
||||
ORDER BY t.count DESC
|
||||
LIMIT 1
|
||||
);
|
||||
|
||||
#6
|
||||
SELECT *
|
||||
FROM travel t
|
||||
WHERE t.money < 5000;
|
||||
|
||||
#7
|
||||
SELECT a.`name`
|
||||
FROM travel t, agency a
|
||||
WHERE t.aid =a.id AND t.money = (
|
||||
SELECT t.money
|
||||
FROM travel t, agency a
|
||||
WHERE t.aid =a.id
|
||||
ORDER BY t.money DESC
|
||||
LIMIT 1
|
||||
);
|
||||
|
||||
#8
|
||||
SELECT SUM(t.time)
|
||||
FROM travel t, agency a
|
||||
WHERE t.aid =a.id AND a.`name` = '青年旅行社';
|
||||
```
|
||||
|
||||
155
最后两周/存储函数练习题.md
Normal file
155
最后两周/存储函数练习题.md
Normal file
@ -0,0 +1,155 @@
|
||||
### 语法结构
|
||||
|
||||
```sql
|
||||
DELIMITER //
|
||||
|
||||
CREATE FUNCTION calculate_annual_salary (
|
||||
monthly_salary DECIMAL(10, 2)
|
||||
)
|
||||
RETURNS DECIMAL(10, 2)
|
||||
DETERMINISTIC | NOT DETERMINISTIC #结果确定/不确定
|
||||
BEGIN
|
||||
RETURN monthly_salary * 12;
|
||||
END //
|
||||
|
||||
DELIMITER ;
|
||||
```
|
||||
|
||||
|
||||
|
||||
### 表结构与数据
|
||||
|
||||
```sql
|
||||
-- 创建数据库
|
||||
CREATE DATABASE company CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
|
||||
|
||||
-- 使用数据库
|
||||
USE company;
|
||||
|
||||
-- 创建 department 表
|
||||
CREATE TABLE department (
|
||||
dept_id INT AUTO_INCREMENT PRIMARY KEY COMMENT '部门ID，主键',
|
||||
dept_name VARCHAR(100) NOT NULL COMMENT '部门名称',
|
||||
location VARCHAR(100) NOT NULL COMMENT '部门所在地'
|
||||
);
|
||||
|
||||
-- 创建 job 表
|
||||
CREATE TABLE job (
|
||||
job_id INT AUTO_INCREMENT PRIMARY KEY COMMENT '职位ID，主键',
|
||||
job_title VARCHAR(100) NOT NULL COMMENT '职位名称',
|
||||
min_salary DECIMAL(10, 2) NOT NULL COMMENT '最低工资',
|
||||
max_salary DECIMAL(10, 2) NOT NULL COMMENT '最高工资'
|
||||
);
|
||||
|
||||
-- 创建 employee 表
|
||||
CREATE TABLE employee (
|
||||
emp_id INT AUTO_INCREMENT PRIMARY KEY COMMENT '员工ID，主键',
|
||||
emp_name VARCHAR(100) NOT NULL COMMENT '员工姓名',
|
||||
salary DECIMAL(10, 2) NOT NULL COMMENT '员工工资',
|
||||
hire_date DATE NOT NULL COMMENT '入职日期',
|
||||
dept_id INT COMMENT '部门ID，外键',
|
||||
job_id INT COMMENT '职位ID，外键',
|
||||
FOREIGN KEY (dept_id) REFERENCES department(dept_id),
|
||||
FOREIGN KEY (job_id) REFERENCES job(job_id)
|
||||
);
|
||||
|
||||
INSERT INTO department (dept_name, location) VALUES
|
||||
('HR', 'New York'),
|
||||
('IT', 'San Francisco'),
|
||||
('Finance', 'Chicago'),
|
||||
('Marketing', 'Los Angeles'),
|
||||
('Sales', 'Boston'),
|
||||
('Operations', 'Houston'),
|
||||
('Research', 'Seattle'),
|
||||
('Customer Support', 'Austin');
|
||||
|
||||
INSERT INTO job (job_title, min_salary, max_salary) VALUES
|
||||
('Manager', 60000.00, 100000.00),
|
||||
('Developer', 50000.00, 80000.00),
|
||||
('Analyst', 45000.00, 70000.00),
|
||||
('Designer', 40000.00, 65000.00),
|
||||
('Sales Executive', 35000.00, 60000.00),
|
||||
('HR Specialist', 40000.00, 70000.00),
|
||||
('Finance Analyst', 50000.00, 75000.00),
|
||||
('Marketing Coordinator', 45000.00, 70000.00),
|
||||
('Operations Manager', 55000.00, 90000.00),
|
||||
('Research Scientist', 60000.00, 95000.00),
|
||||
('Customer Support Representative', 35000.00, 55000.00);
|
||||
|
||||
INSERT INTO employee (emp_name, salary, hire_date, dept_id, job_id) VALUES
|
||||
('Alice', 70000.00, '2020-01-15', 1, 1),
|
||||
('Bob', 65000.00, '2019-03-22', 2, 2),
|
||||
('Charlie', 55000.00, '2018-07-30', 2, 3),
|
||||
('David', 60000.00, '2021-05-10', 3, 4),
|
||||
('Eva', 50000.00, '2017-11-05', 4, 5),
|
||||
('Frank', 75000.00, '2016-09-12', 5, 1),
|
||||
('Grace', 48000.00, '2022-02-20', 1, 2),
|
||||
('Henry', 52000.00, '2021-08-15', 2, 3),
|
||||
('Ivy', 58000.00, '2020-04-10', 3, 4),
|
||||
('Jack', 62000.00, '2019-12-01', 4, 5),
|
||||
('Katie', 53000.00, '2021-07-25', 5, 6),
|
||||
('Leo', 67000.00, '2018-05-18', 6, 7),
|
||||
('Mona', 49000.00, '2020-11-30', 7, 8),
|
||||
('Nina', 71000.00, '2019-02-14', 8, 9),
|
||||
('Oscar', 56000.00, '2022-03-05', 1, 10),
|
||||
('Paul', 63000.00, '2021-09-12', 2, 11),
|
||||
('Quincy', 54000.00, '2020-06-20', 3, 1),
|
||||
('Rachel', 59000.00, '2019-08-15', 4, 2),
|
||||
('Steve', 68000.00, '2018-12-10', 5, 3),
|
||||
('Tina', 51000.00, '2022-01-22', 6, 4),
|
||||
('Uma', 72000.00, '2021-04-18', 7, 5),
|
||||
('Victor', 57000.00, '2020-07-30', 8, 6),
|
||||
('Wendy', 64000.00, '2019-10-05', 1, 7),
|
||||
('Xander', 50000.00, '2022-05-12', 2, 8),
|
||||
('Yara', 69000.00, '2021-03-25', 3, 9),
|
||||
('Zack', 55000.00, '2020-09-15', 4, 10),
|
||||
('Amy', 61000.00, '2019-06-20', 5, 11),
|
||||
('Brian', 74000.00, '2018-04-10', 6, 1),
|
||||
('Cathy', 52000.00, '2022-07-18', 7, 2),
|
||||
('Derek', 67000.00, '2021-12-01', 8, 3);
|
||||
```
|
||||
|
||||
### 练习题
|
||||
|
||||
#### 练习题 1: 计算员工年薪
|
||||
|
||||
创建一个存储函数 `calculate_annual_salary`，接受员工的月薪作为参数，返回其年薪（假设年薪为月薪的 12 倍）。
|
||||
|
||||
#### 练习题 2: 计算员工工龄
|
||||
|
||||
创建一个存储函数 `calculate_years_of_service`，接受员工的入职日期作为参数，返回该员工的工龄（以年为单位）。
|
||||
|
||||
#### 练习题 3: 根据部门计算平均工资
|
||||
|
||||
创建一个存储函数 `calculate_avg_salary_by_dept`，接受部门 ID 作为参数，返回该部门的平均工资。
|
||||
|
||||
#### 练习题 4: 根据职位计算平均工资
|
||||
|
||||
创建一个存储函数 `calculate_avg_salary_by_job`，接受职位 ID 作为参数，返回该职位的平均工资。
|
||||
|
||||
#### 练习题 5: 计算员工税后工资
|
||||
|
||||
创建一个存储函数 `calculate_net_salary`，接受员工的工资作为参数，返回其税后工资（假设税率为 15%）。
|
||||
|
||||
#### 练习题 6: 判断员工是否满足加薪条件
|
||||
|
||||
创建一个存储函数 `is_eligible_for_raise`，接受员工的工资和工龄作为参数，返回一个布尔值（1 或 0）。加薪条件如下：
|
||||
|
||||
- 如果工资低于 60000 且工龄大于等于 3 年，返回 1（满足条件）。
|
||||
- 否则返回 0（不满足条件）。
|
||||
|
||||
#### 练习题 7: 计算部门总工资
|
||||
|
||||
创建一个存储函数 `calculate_total_salary_by_dept`，接受部门 ID 作为参数，返回该部门所有员工的总工资。
|
||||
|
||||
#### 练习题 8: 计算职位总工资
|
||||
|
||||
创建一个存储函数 `calculate_total_salary_by_job`，接受职位 ID 作为参数，返回该职位所有员工的总工资。
|
||||
|
||||
#### 练习题 9: 判断员工是否属于高薪部门
|
||||
|
||||
创建一个存储函数 `is_high_salary_department`，接受部门 ID 作为参数，返回一个布尔值（1 或 0）。如果该部门的平均工资大于等于 70000，返回 1（高薪部门），否则返回 0（非高薪部门）。
|
||||
|
||||
#### 练习题 10: 计算员工的总收入
|
||||
|
||||
创建一个存储函数 `calculate_total_income`，接受员工的工资和奖金（假设奖金为工资的 10%）作为参数，返回其总收入（工资 + 奖金）。
|
||||
529
最后两周/存储过程练习题.md
Normal file
529
最后两周/存储过程练习题.md
Normal file
@ -0,0 +1,529 @@
|
||||
### 语法结构
|
||||
|
||||
```sql
|
||||
DELIMITER //
|
||||
|
||||
CREATE PROCEDURE GetEmployeeCountByDept (
|
||||
IN dept_id INT,
|
||||
OUT employee_count INT
|
||||
)
|
||||
BEGIN
|
||||
SELECT COUNT(*) INTO employee_count
|
||||
FROM employee
|
||||
WHERE dept_id = dept_id;
|
||||
END //
|
||||
|
||||
DELIMITER ;
|
||||
|
||||
IF condition THEN
|
||||
-- 条件为真时执行的代码
|
||||
ELSEIF another_condition THEN
|
||||
-- 另一个条件为真时执行的代码
|
||||
ELSE
|
||||
-- 所有条件都不满足时执行的代码
|
||||
END IF;
|
||||
|
||||
CASE expression
|
||||
WHEN value1 THEN
|
||||
-- 当 expression = value1 时执行的代码
|
||||
WHEN value2 THEN
|
||||
-- 当 expression = value2 时执行的代码
|
||||
ELSE
|
||||
-- 当 expression 不匹配任何值时执行的代码
|
||||
END CASE;
|
||||
|
||||
CASE
|
||||
WHEN condition1 THEN
|
||||
-- 当 condition1 为真时执行的代码
|
||||
WHEN condition2 THEN
|
||||
-- 当 condition2 为真时执行的代码
|
||||
ELSE
|
||||
-- 当所有条件都不满足时执行的代码
|
||||
END CASE;
|
||||
```
|
||||
|
||||
|
||||
|
||||
---
|
||||
|
||||
### 表结构与数据
|
||||
|
||||
```sql
|
||||
-- 创建数据库
|
||||
CREATE DATABASE company CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
|
||||
|
||||
-- 使用数据库
|
||||
USE company;
|
||||
|
||||
-- 创建 department 表
|
||||
CREATE TABLE department (
|
||||
dept_id INT AUTO_INCREMENT PRIMARY KEY COMMENT '部门ID，主键',
|
||||
dept_name VARCHAR(100) NOT NULL COMMENT '部门名称',
|
||||
location VARCHAR(100) NOT NULL COMMENT '部门所在地'
|
||||
);
|
||||
|
||||
-- 创建 job 表
|
||||
CREATE TABLE job (
|
||||
job_id INT AUTO_INCREMENT PRIMARY KEY COMMENT '职位ID，主键',
|
||||
job_title VARCHAR(100) NOT NULL COMMENT '职位名称',
|
||||
min_salary DECIMAL(10, 2) NOT NULL COMMENT '最低工资',
|
||||
max_salary DECIMAL(10, 2) NOT NULL COMMENT '最高工资'
|
||||
);
|
||||
|
||||
-- 创建 employee 表
|
||||
CREATE TABLE employee (
|
||||
emp_id INT AUTO_INCREMENT PRIMARY KEY COMMENT '员工ID，主键',
|
||||
emp_name VARCHAR(100) NOT NULL COMMENT '员工姓名',
|
||||
salary DECIMAL(10, 2) NOT NULL COMMENT '员工工资',
|
||||
hire_date DATE NOT NULL COMMENT '入职日期',
|
||||
dept_id INT COMMENT '部门ID，外键',
|
||||
job_id INT COMMENT '职位ID，外键',
|
||||
FOREIGN KEY (dept_id) REFERENCES department(dept_id),
|
||||
FOREIGN KEY (job_id) REFERENCES job(job_id)
|
||||
);
|
||||
|
||||
INSERT INTO department (dept_name, location) VALUES
|
||||
('HR', 'New York'),
|
||||
('IT', 'San Francisco'),
|
||||
('Finance', 'Chicago'),
|
||||
('Marketing', 'Los Angeles'),
|
||||
('Sales', 'Boston'),
|
||||
('Operations', 'Houston'),
|
||||
('Research', 'Seattle'),
|
||||
('Customer Support', 'Austin');
|
||||
|
||||
INSERT INTO job (job_title, min_salary, max_salary) VALUES
|
||||
('Manager', 60000.00, 100000.00),
|
||||
('Developer', 50000.00, 80000.00),
|
||||
('Analyst', 45000.00, 70000.00),
|
||||
('Designer', 40000.00, 65000.00),
|
||||
('Sales Executive', 35000.00, 60000.00),
|
||||
('HR Specialist', 40000.00, 70000.00),
|
||||
('Finance Analyst', 50000.00, 75000.00),
|
||||
('Marketing Coordinator', 45000.00, 70000.00),
|
||||
('Operations Manager', 55000.00, 90000.00),
|
||||
('Research Scientist', 60000.00, 95000.00),
|
||||
('Customer Support Representative', 35000.00, 55000.00);
|
||||
|
||||
INSERT INTO employee (emp_name, salary, hire_date, dept_id, job_id) VALUES
|
||||
('Alice', 70000.00, '2020-01-15', 1, 1),
|
||||
('Bob', 65000.00, '2019-03-22', 2, 2),
|
||||
('Charlie', 55000.00, '2018-07-30', 2, 3),
|
||||
('David', 60000.00, '2021-05-10', 3, 4),
|
||||
('Eva', 50000.00, '2017-11-05', 4, 5),
|
||||
('Frank', 75000.00, '2016-09-12', 5, 1),
|
||||
('Grace', 48000.00, '2022-02-20', 1, 2),
|
||||
('Henry', 52000.00, '2021-08-15', 2, 3),
|
||||
('Ivy', 58000.00, '2020-04-10', 3, 4),
|
||||
('Jack', 62000.00, '2019-12-01', 4, 5),
|
||||
('Katie', 53000.00, '2021-07-25', 5, 6),
|
||||
('Leo', 67000.00, '2018-05-18', 6, 7),
|
||||
('Mona', 49000.00, '2020-11-30', 7, 8),
|
||||
('Nina', 71000.00, '2019-02-14', 8, 9),
|
||||
('Oscar', 56000.00, '2022-03-05', 1, 10),
|
||||
('Paul', 63000.00, '2021-09-12', 2, 11),
|
||||
('Quincy', 54000.00, '2020-06-20', 3, 1),
|
||||
('Rachel', 59000.00, '2019-08-15', 4, 2),
|
||||
('Steve', 68000.00, '2018-12-10', 5, 3),
|
||||
('Tina', 51000.00, '2022-01-22', 6, 4),
|
||||
('Uma', 72000.00, '2021-04-18', 7, 5),
|
||||
('Victor', 57000.00, '2020-07-30', 8, 6),
|
||||
('Wendy', 64000.00, '2019-10-05', 1, 7),
|
||||
('Xander', 50000.00, '2022-05-12', 2, 8),
|
||||
('Yara', 69000.00, '2021-03-25', 3, 9),
|
||||
('Zack', 55000.00, '2020-09-15', 4, 10),
|
||||
('Amy', 61000.00, '2019-06-20', 5, 11),
|
||||
('Brian', 74000.00, '2018-04-10', 6, 1),
|
||||
('Cathy', 52000.00, '2022-07-18', 7, 2),
|
||||
('Derek', 67000.00, '2021-12-01', 8, 3);
|
||||
```
|
||||
|
||||
|
||||
|
||||
---
|
||||
|
||||
### 练习题
|
||||
|
||||
#### 练习题 1: 插入新员工
|
||||
|
||||
创建一个存储过程 `add_employee`，接受员工姓名、工资、入职日期、部门ID和职位ID作为参数，并将其插入到 `employee` 表中。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP PROCEDURE IF EXISTS add_employee;
|
||||
CREATE PROCEDURE add_employee(IN emp_name VARCHAR(100), IN salary DECIMAL(10,2), IN hire_date DATE, IN dept_id INT, IN job_id INT)
|
||||
BEGIN
|
||||
INSERT INTO employee()
|
||||
VALUES(DEFAULT, emp_name, salary, hire_date, dept_id, job_id);
|
||||
END $$
|
||||
DELIMITER ;
|
||||
|
||||
CALL add_employee('李泽龙', 6666, '2025-3-20', 1, 1);
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 2: 更新员工工资
|
||||
|
||||
创建一个存储过程 `update_employee_salary`，接受员工ID和新的工资作为参数，更新该员工的工资。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP PROCEDURE IF EXISTS update_employee_salary;
|
||||
CREATE PROCEDURE update_employee_salary(IN emp_id INT, IN salary DECIMAL(10, 2))
|
||||
BEGIN
|
||||
UPDATE employee e
|
||||
SET e.salary = salary
|
||||
WHERE e.emp_id = emp_id;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
CALL update_employee_salary(1, 60000);
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 3: 删除员工
|
||||
|
||||
创建一个存储过程 `delete_employee`，接受员工ID作为参数，删除该员工的记录。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP PROCEDURE IF EXISTS delete_employee;
|
||||
CREATE PROCEDURE delete_employee(IN id INT)
|
||||
BEGIN
|
||||
DELETE FROM employee
|
||||
WHERE emp_id = id;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
|
||||
CALL delete_employee(1);
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 4: 查询部门员工
|
||||
|
||||
创建一个存储过程 `get_department_employees`，接受部门ID作为参数，返回该部门所有员工的详细信息。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP PROCEDURE IF EXISTS get_department_employees;
|
||||
CREATE PROCEDURE get_department_employees(IN id INT)
|
||||
BEGIN
|
||||
SELECT e.*
|
||||
FROM employee e
|
||||
WHERE e.dept_id = id;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
CALL get_department_employees(1);
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 5: 查询职位员工
|
||||
|
||||
创建一个存储过程 `get_job_employees`，接受职位ID作为参数，返回该职位所有员工的详细信息。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP PROCEDURE IF EXISTS get_job_employees;
|
||||
CREATE PROCEDURE get_job_employees(IN id INT)
|
||||
BEGIN
|
||||
SELECT e.*
|
||||
FROM employee e
|
||||
WHERE e.job_id = id;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
CALL get_job_employees(1);
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 6: 计算部门平均工资
|
||||
|
||||
创建一个存储过程 `calculate_avg_salary_by_dept`，接受部门ID作为参数，返回该部门的平均工资。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP PROCEDURE IF EXISTS calculate_avg_salary_by_dept;
|
||||
CREATE PROCEDURE calculate_avg_salary_by_dept(IN id INT)
|
||||
BEGIN
|
||||
SELECT AVG(e.salary)
|
||||
FROM employee e
|
||||
WHERE e.dept_id = id;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
CALL calculate_avg_salary_by_dept(1);
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 7: 计算职位平均工资
|
||||
|
||||
创建一个存储过程 `calculate_avg_salary_by_job`，接受职位ID作为参数，返回该职位的平均工资。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP PROCEDURE IF EXISTS calculate_avg_salary_by_job;
|
||||
CREATE PROCEDURE calculate_avg_salary_by_job(IN id INT)
|
||||
BEGIN
|
||||
SELECT AVG(e.salary)
|
||||
FROM employee e
|
||||
WHERE e.job_id = id;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
CALL calculate_avg_salary_by_job(1);
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 8: 查询高薪员工
|
||||
|
||||
创建一个存储过程 `get_high_salary_employees`，接受一个工资阈值作为参数，返回所有工资高于该阈值的员工。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP PROCEDURE IF EXISTS get_high_salary_employees;
|
||||
CREATE PROCEDURE get_high_salary_employees(IN sal DECIMAL(10, 2))
|
||||
BEGIN
|
||||
SELECT e.*
|
||||
FROM employee e
|
||||
WHERE e.salary > sal;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
CALL get_high_salary_employees(50000);
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 9: 查询员工工龄
|
||||
|
||||
创建一个存储过程 `get_employee_years_of_service`，接受员工ID作为参数，返回该员工的工龄（以年为单位）。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP PROCEDURE IF EXISTS get_employee_years_of_service;
|
||||
CREATE PROCEDURE get_employee_years_of_service(IN id INT)
|
||||
BEGIN
|
||||
SELECT -TIMESTAMPDIFF(YEAR,NOW(),e.hire_date)
|
||||
FROM employee e
|
||||
WHERE e.emp_id = id;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
CALL get_employee_years_of_service(1);
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 10: 查询部门员工总数
|
||||
|
||||
创建一个存储过程 `get_department_employee_count`，接受部门ID作为参数，返回该部门的员工总数。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP PROCEDURE IF EXISTS get_department_employee_count;
|
||||
CREATE PROCEDURE get_department_employee_count(IN id INT)
|
||||
BEGIN
|
||||
SELECT COUNT(*)
|
||||
FROM employee e
|
||||
WHERE e.dept_id = id;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
CALL get_department_employee_count(1);
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 11: 查询职位员工总数
|
||||
|
||||
创建一个存储过程 `get_job_employee_count`，接受职位ID作为参数，返回该职位的员工总数。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP PROCEDURE IF EXISTS get_job_employee_count;
|
||||
CREATE PROCEDURE get_job_employee_count(IN id INT)
|
||||
BEGIN
|
||||
SELECT COUNT(*)
|
||||
FROM employee e
|
||||
WHERE e.job_id = id;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
CALL get_job_employee_count(1);
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 12: 查询员工详细信息
|
||||
|
||||
创建一个存储过程 `get_employee_details`，接受员工ID作为参数，返回该员工的姓名、工资、部门名称和职位名称。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP PROCEDURE IF EXISTS get_employee_details;
|
||||
CREATE PROCEDURE get_employee_details(IN emp_id INT)
|
||||
BEGIN
|
||||
SELECT e.emp_name, e.salary, d.dept_name, j.job_title
|
||||
FROM employee e, department d, job j
|
||||
WHERE e.emp_id = emp_id AND e.dept_id = d.dept_id AND e.job_id = j.job_id;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
CALL get_employee_details(1);
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 13: 查询部门最高工资
|
||||
|
||||
创建一个存储过程 `get_department_max_salary`，接受部门ID作为参数，返回该部门的最高工资。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP PROCEDURE IF EXISTS get_department_max_salary;
|
||||
CREATE PROCEDURE get_department_max_salary(IN id INT)
|
||||
BEGIN
|
||||
SELECT MAX(e.salary)
|
||||
FROM employee e
|
||||
WHERE e.dept_id = id;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
CALL get_department_max_salary(1);
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 14: 查询职位最低工资
|
||||
|
||||
创建一个存储过程 `get_job_min_salary`，接受职位ID作为参数，返回该职位的最低工资。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP PROCEDURE IF EXISTS get_job_min_salary;
|
||||
CREATE PROCEDURE get_job_min_salary(IN id INT)
|
||||
BEGIN
|
||||
SELECT MIN(e.salary)
|
||||
FROM employee e
|
||||
WHERE e.dept_id = id;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
CALL get_job_min_salary(1);
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 15: 查询员工工资排名
|
||||
|
||||
创建一个存储过程 `get_employee_salary_rank`，接受员工ID作为参数，返回该员工在公司中的工资排名。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP PROCEDURE IF EXISTS get_employee_salary_rank;
|
||||
CREATE PROCEDURE get_employee_salary_rank(IN emp_id INT)
|
||||
BEGIN
|
||||
SELECT COUNT(*) + 1
|
||||
FROM employee e
|
||||
WHERE e.salary > (
|
||||
SELECT e.salary
|
||||
FROM employee e
|
||||
WHERE e.emp_id = emp_id
|
||||
);
|
||||
END $$
|
||||
DELIMITER ;
|
||||
|
||||
CALL get_employee_salary_rank(2);
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 16: 查询部门工资总和
|
||||
|
||||
创建一个存储过程 `get_department_total_salary`，接受部门ID作为参数，返回该部门所有员工的工资总和。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP PROCEDURE IF EXISTS get_department_total_salary;
|
||||
CREATE PROCEDURE get_department_total_salary(IN id INT)
|
||||
BEGIN
|
||||
SELECT SUM(e.salary)
|
||||
FROM employee e
|
||||
WHERE e.dept_id = id;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
CALL get_department_total_salary(1);
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 17: 查询职位工资总和
|
||||
|
||||
创建一个存储过程 `get_job_total_salary`，接受职位ID作为参数，返回该职位所有员工的工资总和。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP PROCEDURE IF EXISTS get_job_total_salary;
|
||||
CREATE PROCEDURE get_job_total_salary(IN id INT)
|
||||
BEGIN
|
||||
SELECT SUM(e.salary)
|
||||
FROM employee e
|
||||
WHERE e.job_id = id;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
CALL get_job_total_salary(1);
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 18: 查询员工入职年份分布
|
||||
|
||||
创建一个存储过程 `get_employees_by_hire_year`，接受年份作为参数，返回该年份入职的所有员工。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP PROCEDURE IF EXISTS get_employees_by_hire_year;
|
||||
CREATE PROCEDURE get_employees_by_hire_year(IN y INT)
|
||||
BEGIN
|
||||
SELECT *
|
||||
FROM employee e
|
||||
WHERE YEAR(e.hire_date) = y;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
CALL get_employees_by_hire_year(2020);
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 19: 查询部门工资分布
|
||||
|
||||
创建一个存储过程 `get_department_salary_distribution`，接受部门ID作为参数，返回该部门工资的分布情况（如最高、最低、平均工资）。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP PROCEDURE IF EXISTS get_department_salary_distribution;
|
||||
CREATE PROCEDURE get_department_salary_distribution(IN id INT)
|
||||
BEGIN
|
||||
SELECT MAX(e.salary), MIN(e.salary), AVG(e.salary)
|
||||
FROM employee e
|
||||
WHERE e.dept_id = id;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
CALL get_department_salary_distribution(1);
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 20: 查询职位工资分布
|
||||
|
||||
创建一个存储过程 `get_job_salary_distribution`，接受职位ID作为参数，返回该职位工资的分布情况（如最高、最低、平均工资）。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP PROCEDURE IF EXISTS get_job_salary_distribution;
|
||||
CREATE PROCEDURE get_job_salary_distribution(IN id INT)
|
||||
BEGIN
|
||||
SELECT MAX(e.salary), MIN(e.salary), AVG(e.salary)
|
||||
FROM employee e
|
||||
WHERE e.job_id = id;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
CALL get_job_salary_distribution(1);
|
||||
```
|
||||
|
||||
610
最后两周/触发器练习题.md
Normal file
610
最后两周/触发器练习题.md
Normal file
@ -0,0 +1,610 @@
|
||||
### 语法结构
|
||||
|
||||
```sql
|
||||
DELIMITER //
|
||||
CREATE TRIGGER trigger_name
|
||||
{BEFORE | AFTER} {INSERT | UPDATE | DELETE} ON table_name
|
||||
FOR EACH ROW
|
||||
BEGIN
|
||||
-- 触发器的逻辑代码
|
||||
-- 可以包含 SQL 语句、流程控制语句（如 IF、CASE 等）、变量声明等
|
||||
END//
|
||||
DELIMITER ;
|
||||
```
|
||||
|
||||
### 表结构和数据
|
||||
|
||||
```sql
|
||||
-- 创建数据库
|
||||
CREATE DATABASE company CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
|
||||
|
||||
-- 使用数据库
|
||||
USE company;
|
||||
|
||||
-- 创建 department 表
|
||||
CREATE TABLE department (
|
||||
dept_id INT AUTO_INCREMENT PRIMARY KEY COMMENT '部门ID，主键',
|
||||
dept_name VARCHAR(100) NOT NULL COMMENT '部门名称',
|
||||
location VARCHAR(100) NOT NULL COMMENT '部门所在地'
|
||||
);
|
||||
|
||||
-- 创建 job 表
|
||||
CREATE TABLE job (
|
||||
job_id INT AUTO_INCREMENT PRIMARY KEY COMMENT '职位ID，主键',
|
||||
job_title VARCHAR(100) NOT NULL COMMENT '职位名称',
|
||||
min_salary DECIMAL(10, 2) NOT NULL COMMENT '最低工资',
|
||||
max_salary DECIMAL(10, 2) NOT NULL COMMENT '最高工资'
|
||||
);
|
||||
|
||||
-- 创建 employee 表
|
||||
CREATE TABLE employee (
|
||||
emp_id INT AUTO_INCREMENT PRIMARY KEY COMMENT '员工ID，主键',
|
||||
emp_name VARCHAR(100) NOT NULL COMMENT '员工姓名',
|
||||
salary DECIMAL(10, 2) NOT NULL COMMENT '员工工资',
|
||||
hire_date DATE NOT NULL COMMENT '入职日期',
|
||||
dept_id INT COMMENT '部门ID，外键',
|
||||
job_id INT COMMENT '职位ID，外键',
|
||||
FOREIGN KEY (dept_id) REFERENCES department(dept_id),
|
||||
FOREIGN KEY (job_id) REFERENCES job(job_id)
|
||||
);
|
||||
|
||||
INSERT INTO department (dept_name, location) VALUES
|
||||
('HR', 'New York'),
|
||||
('IT', 'San Francisco'),
|
||||
('Finance', 'Chicago'),
|
||||
('Marketing', 'Los Angeles'),
|
||||
('Sales', 'Boston'),
|
||||
('Operations', 'Houston'),
|
||||
('Research', 'Seattle'),
|
||||
('Customer Support', 'Austin');
|
||||
|
||||
INSERT INTO job (job_title, min_salary, max_salary) VALUES
|
||||
('Manager', 60000.00, 100000.00),
|
||||
('Developer', 50000.00, 80000.00),
|
||||
('Analyst', 45000.00, 70000.00),
|
||||
('Designer', 40000.00, 65000.00),
|
||||
('Sales Executive', 35000.00, 60000.00),
|
||||
('HR Specialist', 40000.00, 70000.00),
|
||||
('Finance Analyst', 50000.00, 75000.00),
|
||||
('Marketing Coordinator', 45000.00, 70000.00),
|
||||
('Operations Manager', 55000.00, 90000.00),
|
||||
('Research Scientist', 60000.00, 95000.00),
|
||||
('Customer Support Representative', 35000.00, 55000.00);
|
||||
|
||||
INSERT INTO employee (emp_name, salary, hire_date, dept_id, job_id) VALUES
|
||||
('Alice', 70000.00, '2020-01-15', 1, 1),
|
||||
('Bob', 65000.00, '2019-03-22', 2, 2),
|
||||
('Charlie', 55000.00, '2018-07-30', 2, 3),
|
||||
('David', 60000.00, '2021-05-10', 3, 4),
|
||||
('Eva', 50000.00, '2017-11-05', 4, 5),
|
||||
('Frank', 75000.00, '2016-09-12', 5, 1),
|
||||
('Grace', 48000.00, '2022-02-20', 1, 2),
|
||||
('Henry', 52000.00, '2021-08-15', 2, 3),
|
||||
('Ivy', 58000.00, '2020-04-10', 3, 4),
|
||||
('Jack', 62000.00, '2019-12-01', 4, 5),
|
||||
('Katie', 53000.00, '2021-07-25', 5, 6),
|
||||
('Leo', 67000.00, '2018-05-18', 6, 7),
|
||||
('Mona', 49000.00, '2020-11-30', 7, 8),
|
||||
('Nina', 71000.00, '2019-02-14', 8, 9),
|
||||
('Oscar', 56000.00, '2022-03-05', 1, 10),
|
||||
('Paul', 63000.00, '2021-09-12', 2, 11),
|
||||
('Quincy', 54000.00, '2020-06-20', 3, 1),
|
||||
('Rachel', 59000.00, '2019-08-15', 4, 2),
|
||||
('Steve', 68000.00, '2018-12-10', 5, 3),
|
||||
('Tina', 51000.00, '2022-01-22', 6, 4),
|
||||
('Uma', 72000.00, '2021-04-18', 7, 5),
|
||||
('Victor', 57000.00, '2020-07-30', 8, 6),
|
||||
('Wendy', 64000.00, '2019-10-05', 1, 7),
|
||||
('Xander', 50000.00, '2022-05-12', 2, 8),
|
||||
('Yara', 69000.00, '2021-03-25', 3, 9),
|
||||
('Zack', 55000.00, '2020-09-15', 4, 10),
|
||||
('Amy', 61000.00, '2019-06-20', 5, 11),
|
||||
('Brian', 74000.00, '2018-04-10', 6, 1),
|
||||
('Cathy', 52000.00, '2022-07-18', 7, 2),
|
||||
('Derek', 67000.00, '2021-12-01', 8, 3);
|
||||
```
|
||||
|
||||
### `SIGNAL` 语句的基本语法
|
||||
|
||||
```sql
|
||||
SIGNAL SQLSTATE '状态码'
|
||||
SET MESSAGE_TEXT = '错误消息';
|
||||
```
|
||||
|
||||
- **SQLSTATE**：一个 5 字符的字符串，表示错误的状态码。MySQL 使用 `'45000'` 表示用户定义的错误。
|
||||
- **MESSAGE_TEXT**：自定义的错误消息，用于描述错误的原因。
|
||||
|
||||
### 练习题
|
||||
|
||||
#### 练习题 1: 工资范围验证
|
||||
|
||||
创建一个触发器 `before_employee_insert`，在插入 `employee` 表数据之前，检查员工的工资是否在其对应职位的 `min_salary` 和 `max_salary` 范围内。如果超出范围，阻止插入并抛出错误。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP TRIGGER IF EXISTS before_employee_insert;
|
||||
CREATE TRIGGER before_employee_insert
|
||||
BEFORE INSERT ON employee
|
||||
FOR EACH ROW
|
||||
BEGIN
|
||||
|
||||
IF NEW.salary > (
|
||||
SELECT j.max_salary
|
||||
FROM job j
|
||||
WHERE j.job_id = NEW.job_id
|
||||
) OR NEW.salary < (
|
||||
SELECT j.min_salary
|
||||
FROM job j
|
||||
WHERE j.job_id = NEW.job_id
|
||||
) THEN
|
||||
SIGNAL SQLSTATE '45000'
|
||||
SET MESSAGE_TEXT = '工资值错误，不在职务工资范围内';
|
||||
END IF;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
|
||||
INSERT INTO employee
|
||||
VALUES(DEFAULT, '雷昊', 0, NOW(), 1, 1);
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 2: 自动更新部门人数
|
||||
|
||||
创建一个触发器 `after_employee_insert`，在插入 `employee` 表数据之后，自动更新 `department` 表中的部门人数（假设 `department` 表新增一个字段 `employee_count`）。
|
||||
|
||||
```sql
|
||||
ALTER TABLE department ADD employee_count INT UNSIGNED;
|
||||
|
||||
DELIMITER $$
|
||||
DROP TRIGGER IF EXISTS after_employee_insert;
|
||||
CREATE TRIGGER after_employee_insert
|
||||
AFTER INSERT ON employee
|
||||
FOR EACH ROW
|
||||
BEGIN
|
||||
UPDATE department d
|
||||
SET d.employee_count = (
|
||||
SELECT COUNT(*)
|
||||
FROM employee e
|
||||
WHERE e.dept_id = d.dept_id
|
||||
);
|
||||
END $$
|
||||
DELIMITER ;
|
||||
|
||||
INSERT INTO employee
|
||||
VALUES(DEFAULT, '雷昊', 60000.00, NOW(), 1, 1);
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 3: 工资变更日志
|
||||
|
||||
创建一个触发器 `after_employee_update`，在更新 `employee` 表的 `salary` 字段后，将变更记录插入到一个新的日志表 `salary_log` 中，记录员工 ID、旧工资、新工资和变更时间。
|
||||
|
||||
```sql
|
||||
DROP TABLE IF EXISTS salary_log;
|
||||
CREATE TABLE salary_log(
|
||||
emp_id INT,
|
||||
old_salary DECIMAL(10, 2),
|
||||
new_slaray DECIMAL(10, 2),
|
||||
update_date DATE
|
||||
);
|
||||
|
||||
DELIMITER $$
|
||||
DROP TRIGGER IF EXISTS after_employee_update;
|
||||
CREATE TRIGGER after_employee_update
|
||||
BEFORE UPDATE ON employee
|
||||
FOR EACH ROW
|
||||
BEGIN
|
||||
IF NEW.salary <> OLD.salary THEN
|
||||
INSERT INTO salary_log()
|
||||
VALUES(NEW.emp_id, OLD.salary, NEW.salary, NOW());
|
||||
END IF;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
|
||||
UPDATE employee e
|
||||
SET e.salary = 10
|
||||
WHERE e.emp_id = 1;
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 4: 删除员工时备份数据
|
||||
|
||||
创建一个触发器 `before_employee_delete`，在删除 `employee` 表数据之前，将被删除的员工数据插入到一个备份表 `employee_backup` 中。
|
||||
|
||||
```sql
|
||||
CREATE TABLE employee_backup AS
|
||||
SELECT *
|
||||
FROM employee
|
||||
WHERE 0;
|
||||
|
||||
DELIMITER $$
|
||||
DROP TRIGGER IF EXISTS before_employee_delete;
|
||||
CREATE TRIGGER before_employee_delete
|
||||
BEFORE DELETE ON employee
|
||||
FOR EACH ROW
|
||||
BEGIN
|
||||
INSERT INTO employee_backup()
|
||||
VALUES(OLD.emp_id, OLD.emp_name, OLD.salary, OLD.hire_date, OLD.dept_id, OLD.job_id);
|
||||
END $$
|
||||
DELIMITER ;
|
||||
|
||||
DELETE FROM employee
|
||||
WHERE emp_id = 20;
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 5: 自动设置默认职位
|
||||
|
||||
创建一个触发器 `before_employee_insert`，在插入 `employee` 表数据时，如果未指定 `job_id`，则自动将其设置为 `job` 表中的默认职位（假设默认职位的 `job_id` 为 1）。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP TRIGGER IF EXISTS before_employee_insert;
|
||||
CREATE TRIGGER before_employee_insert
|
||||
BEFORE INSERT ON employee
|
||||
FOR EACH ROW
|
||||
BEGIN
|
||||
IF NEW.job_id IS NULL THEN
|
||||
SET NEW.job_id = 1;
|
||||
END IF;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
|
||||
INSERT INTO employee
|
||||
VALUES(DEFAULT, '雷昊', 60000.00, NOW(), 1, NULL);
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 6: 防止修改入职日期
|
||||
|
||||
创建一个触发器 `before_employee_update`，在更新 `employee` 表数据时，防止修改 `hire_date` 字段。如果尝试修改，抛出错误。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP TRIGGER IF EXISTS before_employee_update;
|
||||
CREATE TRIGGER before_employee_update
|
||||
BEFORE UPDATE ON employee
|
||||
FOR EACH ROW
|
||||
BEGIN
|
||||
IF NEW.hire_date <> OLD.hire_date THEN
|
||||
SIGNAL SQLSTATE '45000'
|
||||
SET MESSAGE_TEXT='不允许修改用户的入职时间';
|
||||
END IF;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
UPDATE employee e
|
||||
SET e.hire_date = '2025-3-20'
|
||||
WHERE e.emp_id = 1;
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 7: 自动计算工龄
|
||||
|
||||
创建一个触发器 `before_employee_insert`，在插入 `employee` 表数据时，自动计算员工的工龄（以年为单位），并将其存储到一个新字段 `years_of_service` 中。
|
||||
|
||||
```sql
|
||||
ALTER TABLE employee ADD years_of_service INT;
|
||||
|
||||
DELIMITER $$
|
||||
DROP TRIGGER IF EXISTS before_employee_insert;
|
||||
CREATE TRIGGER before_employee_insert
|
||||
BEFORE INSERT ON employee
|
||||
FOR EACH ROW
|
||||
BEGIN
|
||||
SET NEW.years_of_service = TIMESTAMPDIFF(YEAR,NEW.hire_date,NOW());
|
||||
END $$
|
||||
DELIMITER ;
|
||||
|
||||
SELECT TIMESTAMPDIFF(YEAR,e.hire_date,NOW())
|
||||
FROM employee e;
|
||||
|
||||
INSERT INTO employee
|
||||
VALUES(DEFAULT, '雷昊', 60000.00, '2022-12-31', 1, 1, NULL);
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 8: 防止删除部门
|
||||
|
||||
创建一个触发器 `before_department_delete`，在删除 `department` 表数据之前，检查该部门是否还有员工。如果有员工，阻止删除并抛出错误。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP TRIGGER IF EXISTS before_department_delete;
|
||||
CREATE TRIGGER before_department_delete
|
||||
BEFORE DELETE ON department
|
||||
FOR EACH ROW
|
||||
BEGIN
|
||||
IF (SELECT COUNT(*) FROM employee e WHERE e.dept_id = OLD.dept_id) > 0 THEN
|
||||
SIGNAL SQLSTATE '45000'
|
||||
SET MESSAGE_TEXT = '该部门有员工无法删除';
|
||||
END IF;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
|
||||
DELETE FROM department
|
||||
WHERE dept_id = 1;
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 9: 自动更新职位工资范围
|
||||
|
||||
创建一个触发器 `after_job_update`，在更新 `job` 表的 `min_salary` 或 `max_salary` 字段后，自动调整 `employee` 表中相关员工的工资，使其符合新的工资范围。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP TRIGGER IF EXISTS after_job_update;
|
||||
CREATE TRIGGER after_job_update
|
||||
AFTER UPDATE ON job
|
||||
FOR EACH ROW
|
||||
BEGIN
|
||||
UPDATE employee
|
||||
SET salary = IF(salary > NEW.max_salary, NEW.max_salary, IF(salary < NEW.min_salary, min_salary, salary))
|
||||
WHERE job_id = NEW.job_id;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 10: 记录部门变更
|
||||
|
||||
创建一个触发器 `after_employee_update`，在更新 `employee` 表的 `dept_id` 字段后，将变更记录插入到一个新的日志表 `department_change_log` 中，记录员工 ID、旧部门 ID、新部门 ID 和变更时间。
|
||||
|
||||
```sql
|
||||
CREATE TABLE department_change_log(
|
||||
emp_id INT,
|
||||
old_dept_id INT,
|
||||
new_dept_id INT,
|
||||
update_date DATE
|
||||
);
|
||||
|
||||
DELIMITER $$
|
||||
DROP TRIGGER IF EXISTS after_employee_update;
|
||||
CREATE TRIGGER after_employee_update
|
||||
AFTER UPDATE ON employee
|
||||
FOR EACH ROW
|
||||
BEGIN
|
||||
IF NEW.dept_id <> OLD.dept_id THEN
|
||||
INSERT INTO department_change_log()
|
||||
VALUES(NEW.emp_id, OLD.dept_id, NEW.dept_id, NOW());
|
||||
END IF;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 11: 防止插入重复职位
|
||||
|
||||
创建一个触发器 `before_job_insert`，在插入 `job` 表数据之前，检查职位名称是否已存在。如果存在，阻止插入并抛出错误。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP TRIGGER IF EXISTS before_job_insert;
|
||||
CREATE TRIGGER before_job_insert
|
||||
BEFORE INSERT ON job
|
||||
FOR EACH ROW
|
||||
BEGIN
|
||||
IF (SELECT COUNT(*) FROM job WHERE job_id = NEW.job_id) = 1 THEN
|
||||
SIGNAL SQLSTATE '45000'
|
||||
SET MESSAGE_TEXT = '职位名称已存在';
|
||||
END IF;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 12: 自动更新员工总数
|
||||
|
||||
创建一个触发器 `after_employee_insert`，在插入 `employee` 表数据之后，自动更新一个统计表 `employee_statistics` 中的员工总数。
|
||||
|
||||
```sql
|
||||
CREATE TABLE employee_statistics(
|
||||
marking VARCHAR(20),
|
||||
num INT
|
||||
);
|
||||
INSERT INTO employee_statistics()
|
||||
VALUES('count', 0);
|
||||
|
||||
DELIMITER $$
|
||||
DROP TRIGGER IF EXISTS after_employee_insert;
|
||||
CREATE TRIGGER after_employee_insert
|
||||
AFTER INSERT ON employee
|
||||
FOR EACH ROW
|
||||
BEGIN
|
||||
UPDATE employee_statistics
|
||||
SET num = (SELECT COUNT(*) FROM employee)
|
||||
WHERE marking = 'count';
|
||||
END $$
|
||||
DELIMITER ;
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 13: 防止修改部门所在地
|
||||
|
||||
创建一个触发器 `before_department_update`，在更新 `department` 表数据时，防止修改 `location` 字段。如果尝试修改，抛出错误。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP TRIGGER IF EXISTS before_department_update;
|
||||
CREATE TRIGGER before_department_update
|
||||
BEFORE UPDATE ON department
|
||||
FOR EACH ROW
|
||||
BEGIN
|
||||
IF NEW.location <> OLD.location THEN
|
||||
SIGNAL SQLSTATE '45000'
|
||||
SET MESSAGE_TEXT = '无法更新部分的位置';
|
||||
END IF;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 14: 自动调整工资
|
||||
|
||||
创建一个触发器 `before_employee_insert`，在插入 `employee` 表数据时，如果工资低于职位的最低工资，则自动将其调整为最低工资。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP TRIGGER IF EXISTS before_employee_insert;
|
||||
CREATE TRIGGER before_employee_insert
|
||||
BEFORE INSERT ON employee
|
||||
FOR EACH ROW
|
||||
BEGIN
|
||||
IF NEW.salary < (SELECT min_salary FROM job WHERE job_id = NEW.job_id ) THEN
|
||||
SET NEW.salary = min_salary;
|
||||
END IF;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 15: 记录职位变更
|
||||
|
||||
创建一个触发器 `after_employee_update`，在更新 `employee` 表的 `job_id` 字段后，将变更记录插入到一个新的日志表 `job_change_log` 中，记录员工 ID、旧职位 ID、新职位 ID 和变更时间。
|
||||
|
||||
```sql
|
||||
CREATE TABLE job_change_log(
|
||||
emp_id INT,
|
||||
old_job_id INT,
|
||||
new_job_id INT,
|
||||
update_date DATE
|
||||
);
|
||||
DELIMITER $$
|
||||
DROP TRIGGER IF EXISTS after_employee_update;
|
||||
CREATE TRIGGER after_employee_update
|
||||
AFTER UPDATE ON employee
|
||||
FOR EACH ROW
|
||||
BEGIN
|
||||
IF NEW.job_id <> OLD.job_id THEN
|
||||
INSERT INTO job_change_log()
|
||||
VALUES(NEW.emp_id, OLD.job_id, NEW.job_id, NOW());
|
||||
END IF;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 16: 防止删除职位
|
||||
|
||||
创建一个触发器 `before_job_delete`，在删除 `job` 表数据之前，检查该职位是否还有员工。如果有员工，阻止删除并抛出错误。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP TRIGGER IF EXISTS before_job_delete;
|
||||
CREATE TRIGGER before_job_delete
|
||||
BEFORE DELETE ON job
|
||||
FOR EACH ROW
|
||||
BEGIN
|
||||
IF (SELECT COUNT(*) FROM employee WHERE job_id = OLD.job_id) > 0 THEN
|
||||
SIGNAL SQLSTATE '45000'
|
||||
SET MESSAGE_TEXT = '该职位还有员工';
|
||||
END IF;
|
||||
END $$
|
||||
DELIMITER ;
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 17: 自动更新部门平均工资
|
||||
|
||||
创建一个触发器 `after_employee_insert`，在插入 `employee` 表数据之后，自动更新 `department` 表中的部门平均工资（假设 `department` 表新增一个字段 `avg_salary`）。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP TRIGGER IF EXISTS after_employee_insert;
|
||||
CREATE TRIGGER after_employee_insert
|
||||
AFTER INSERT ON employee
|
||||
FOR EACH ROW
|
||||
BEGIN
|
||||
UPDATE department d
|
||||
SET d.avg_salary = (SELECT AVG(e.salary) FROM employee e WHERE d.dept_id = e.dept_id)
|
||||
WHERE NEW.dept_id = d.dept_id;
|
||||
|
||||
END $$
|
||||
DELIMITER ;
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 18: 防止插入未来入职日期
|
||||
|
||||
创建一个触发器 `before_employee_insert`，在插入 `employee` 表数据时，检查 `hire_date` 是否晚于当前日期。如果是，阻止插入并抛出错误。
|
||||
|
||||
```sql
|
||||
DELIMITER $$
|
||||
DROP TRIGGER IF EXISTS before_employee_insert;
|
||||
CREATE TRIGGER before_employee_insert
|
||||
BEFORE INSERT ON employee
|
||||
FOR EACH ROW
|
||||
BEGIN
|
||||
IF NEW.hire_date < CURDATE() THEN
|
||||
SIGNAL SQLSTATE '45000'
|
||||
SET MESSAGE_TEXT = '入职日期不得晚于当前日期';
|
||||
END IF;
|
||||
|
||||
END $$
|
||||
DELIMITER ;
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 19: 自动生成员工编号
|
||||
|
||||
创建一个触发器 `before_employee_insert`，在插入 `employee` 表数据时，自动生成一个唯一的员工编号（格式为 `EMP-年份-序号`，例如 `EMP-2023-001`），并将其存储到一个新字段 `emp_code` 中。
|
||||
|
||||
```sql
|
||||
ALTER TABLE employee ADD emp_code VARCHAR(30);
|
||||
|
||||
DELIMITER $$
|
||||
DROP TRIGGER IF EXISTS before_employee_insert;
|
||||
CREATE TRIGGER before_employee_insert
|
||||
BEFORE INSERT ON employee
|
||||
FOR EACH ROW
|
||||
BEGIN
|
||||
SET NEW.emp_code = CONCAT('EMP-',YEAR(NOW()),'-', (LAST_INSERT_ID()+1));
|
||||
END $$
|
||||
DELIMITER ;
|
||||
INSERT INTO employee
|
||||
VALUES(DEFAULT, '雷昊', 0, NOW(), 1, 1, NULL, NULL);
|
||||
```
|
||||
|
||||
|
||||
|
||||
#### 练习题 20: 记录员工离职
|
||||
|
||||
创建一个触发器 `after_employee_delete`，在删除 `employee` 表数据之后，将被删除的员工信息插入到一个离职记录表 `employee_exit_log` 中，记录员工 ID、姓名、离职时间和原因（假设原因由用户输入）。
|
||||
|
||||
```sql
|
||||
CREATE TABLE employee_exit_log(
|
||||
emp_id INT,
|
||||
emp_name VARCHAR(20),
|
||||
quit_date DATE,
|
||||
quit_reason VARCHAR(50)
|
||||
);
|
||||
|
||||
DELIMITER $$
|
||||
DROP TRIGGER IF EXISTS after_employee_delete;
|
||||
CREATE TRIGGER after_employee_delete
|
||||
AFTER DELETE ON employee
|
||||
FOR EACH ROW
|
||||
BEGIN
|
||||
INSERT INTO employee_exit_log()
|
||||
VALUES(OLD.emp_id, OLD.emp_name, NOW(), NULL);
|
||||
END $$
|
||||
DELIMITER ;
|
||||
```
|
||||
|
||||
@ -1,16 +1,16 @@
|
||||
|
||||
/*----------------------------------------------------------------------
|
||||
【程序设计】
|
||||
【程序设计】
|
||||
------------------------------------------------------------------------
|
||||
编写一个 C 语言函数，函数接收一个整数数组 arr 以及数组的长度 size 作为参数，使用 bool 类型返回该数组中是否存在重复的元素。在 main 函数中，输入多个正整数（输入非数字字符表示输入结束）并调用该函数，根据返回结果输出相应的提示信息。
|
||||
示例：
|
||||
【请输入多个整数（输入非数字字符结束输入）：】1 2 3 4 5 5 6 a
|
||||
数组中存在重复元素。
|
||||
编写一个 C 语言函数，函数接收一个整数数组 arr 以及数组的长度 size 作为参数，使用 bool 类型返回该数组中是否存在重复的元素。在 main 函数中，输入多个正整数（输入非数字字符表示输入结束）并调用该函数，根据返回结果输出相应的提示信息。
|
||||
示例：
|
||||
【请输入多个整数（输入非数字字符结束输入）：】1 2 3 4 5 5 6 a
|
||||
数组中存在重复元素。
|
||||
------------------------------------------------------------------------
|
||||
注意：部分源程序给出如下。请勿改动主函数 main 或其它函数中给出的内容，仅在
|
||||
Program-End之间填入若干语句。
|
||||
不要删除标志否则不得分。
|
||||
不要修改或删除Program-End之外的内容否则不得分。
|
||||
注意：部分源程序给出如下。请勿改动主函数 main 或其它函数中给出的内容，仅在
|
||||
Program-End之间填入若干语句。
|
||||
不要删除标志否则不得分。
|
||||
不要修改或删除Program-End之外的内容否则不得分。
|
||||
----------------------------------------------------------------------*/
|
||||
#include <stdio.h>
|
||||
#include <stdbool.h>
|
||||
@ -36,12 +36,12 @@ int main() {
|
||||
int *arr = (int *)malloc(capacity * sizeof(int));
|
||||
|
||||
if (arr == NULL) {
|
||||
printf("内存分配失败！\n");
|
||||
printf("内存分配失败！\n");
|
||||
return 1;
|
||||
}
|
||||
int size = 0;
|
||||
int num;
|
||||
printf("【请输入多个整数（输入非数字字符结束输入）：】");
|
||||
printf("【请输入多个整数（输入非数字字符结束输入）：】");
|
||||
|
||||
while (scanf("%d", &num) == 1) {
|
||||
|
||||
@ -50,7 +50,7 @@ int main() {
|
||||
arr = (int *)realloc(arr, capacity * sizeof(int));
|
||||
|
||||
if (arr == NULL) {
|
||||
printf("内存分配失败！\n");
|
||||
printf("内存分配失败！\n");
|
||||
return 1;
|
||||
}
|
||||
}
|
||||
@ -62,9 +62,9 @@ int main() {
|
||||
|
||||
|
||||
if (hasDuplicates(arr, size)) {
|
||||
printf("数组中存在重复元素。\n");
|
||||
printf("数组中存在重复元素。\n");
|
||||
} else {
|
||||
printf("数组中不存在重复元素。\n");
|
||||
printf("数组中不存在重复元素。\n");
|
||||
}
|
||||
|
||||
|
||||
|
||||
@ -1,43 +1,43 @@
|
||||
/*----------------------------------------------------------------------
|
||||
【程序设计】
|
||||
【程序设计】
|
||||
------------------------------------------------------------------------
|
||||
现在有一位赛车手要驾驶一台电动摩托车去完成多段赛程。这台电动摩托车的电池电量存储
|
||||
上限是 100 度电哦，它有一个标称的平均电耗，也就是每行驶 100 公里，就会消耗 10度
|
||||
电。这里有个很重要的前提条件要大家牢记呀，每一段赛程的距离都是小于 600 公里的哦，
|
||||
并且每次出发的时候，电动摩托车的电池都是充满电的状态呢。还有一个关键的规则得注意
|
||||
哦，如果电动摩托车到达某个地点之后，赛车手查看发现电池内剩余的电量低于电池总电量
|
||||
的 10%（也就是 100×10% = 10 度电或者更少啦），那这个时候就必须得在这个地方给电
|
||||
动摩托车充电了呢，请帮忙计算一下，这名驾驶员在赛程中的哪几段赛程前是需要充电的。
|
||||
现在有一位赛车手要驾驶一台电动摩托车去完成多段赛程。这台电动摩托车的电池电量存储
|
||||
上限是 100 度电哦，它有一个标称的平均电耗，也就是每行驶 100 公里，就会消耗 10度
|
||||
电。这里有个很重要的前提条件要大家牢记呀，每一段赛程的距离都是小于 600 公里的哦，
|
||||
并且每次出发的时候，电动摩托车的电池都是充满电的状态呢。还有一个关键的规则得注意
|
||||
哦，如果电动摩托车到达某个地点之后，赛车手查看发现电池内剩余的电量低于电池总电量
|
||||
的 10%（也就是 100×10% = 10 度电或者更少啦），那这个时候就必须得在这个地方给电
|
||||
动摩托车充电了呢，请帮忙计算一下，这名驾驶员在赛程中的哪几段赛程前是需要充电的。
|
||||
|
||||
示例1：
|
||||
【请输入赛程段数：】
|
||||
示例1：
|
||||
【请输入赛程段数：】
|
||||
5
|
||||
【请输入各段赛程距离，单位公里：】
|
||||
【请输入各段赛程距离，单位公里：】
|
||||
380 200 390 400 300
|
||||
【需要在以下几段赛程前充电：】
|
||||
第 3 段赛程前
|
||||
第 5 段赛程前
|
||||
【需要在以下几段赛程前充电：】
|
||||
第 3 段赛程前
|
||||
第 5 段赛程前
|
||||
|
||||
示例2：
|
||||
【请输入赛程段数：】
|
||||
示例2：
|
||||
【请输入赛程段数：】
|
||||
4
|
||||
【请输入各段赛程距离，单位公里：】
|
||||
【请输入各段赛程距离，单位公里：】
|
||||
190 140 110 80
|
||||
无需充电。
|
||||
无需充电。
|
||||
|
||||
------------------------------------------------------------------------
|
||||
注意：部分源程序给出如下。请勿改动主函数 main 或其它函数中给出的内容，仅在
|
||||
Program-End之间填入若干语句。
|
||||
不要删除标志否则不得分。
|
||||
不要修改或删除Program-End之外的内容否则不得分。
|
||||
注意：部分源程序给出如下。请勿改动主函数 main 或其它函数中给出的内容，仅在
|
||||
Program-End之间填入若干语句。
|
||||
不要删除标志否则不得分。
|
||||
不要修改或删除Program-End之外的内容否则不得分。
|
||||
----------------------------------------------------------------------*/
|
||||
#include <stdio.h>
|
||||
#include <stdlib.h> // 引入stdlib.h用于动态内存分配相关操作
|
||||
#include <stdlib.h> // 引入stdlib.h用于动态内存分配相关操作
|
||||
|
||||
#define TANK_CAPACITY 100 // 电池总容量（单位：度）
|
||||
#define LOW_FUEL_LIMIT (0.10 * TANK_CAPACITY) // 低电量阈值（10%）
|
||||
#define AVG_CONSUMPTION_PER_100KM 10 // 平均电耗（单位：度/百公里）
|
||||
#define FUEL_CONSUMPTION_PER_KM (AVG_CONSUMPTION_PER_100KM / 100.0) // 每公里电耗（单位：度/公里）
|
||||
#define TANK_CAPACITY 100 // 电池总容量（单位：度）
|
||||
#define LOW_FUEL_LIMIT (0.10 * TANK_CAPACITY) // 低电量阈值（10%）
|
||||
#define AVG_CONSUMPTION_PER_100KM 10 // 平均电耗（单位：度/百公里）
|
||||
#define FUEL_CONSUMPTION_PER_KM (AVG_CONSUMPTION_PER_100KM / 100.0) // 每公里电耗（单位：度/公里）
|
||||
|
||||
int checkRefuelStops(int trips[], int count, int results[]) {
|
||||
int refuel_count = 0;
|
||||
@ -56,17 +56,17 @@ int checkRefuelStops(int trips[], int count, int results[]) {
|
||||
|
||||
int main() {
|
||||
int num_trips;
|
||||
printf("【请输入赛程段数：】\n");
|
||||
printf("【请输入赛程段数：】\n");
|
||||
scanf("%d", &num_trips);
|
||||
|
||||
|
||||
int *trips = (int *)malloc(num_trips * sizeof(int));
|
||||
if (trips == NULL) {
|
||||
printf("内存分配失败！\n");
|
||||
printf("内存分配失败！\n");
|
||||
return 1;
|
||||
}
|
||||
|
||||
printf("【请输入各段赛程距离，单位公里：】\n");
|
||||
printf("【请输入各段赛程距离，单位公里：】\n");
|
||||
for (int i = 0; i < num_trips; ++i) {
|
||||
scanf("%d", &trips[i]);
|
||||
}
|
||||
@ -74,7 +74,7 @@ int main() {
|
||||
|
||||
int *results = (int *)malloc(num_trips * sizeof(int));
|
||||
if (results == NULL) {
|
||||
printf("内存分配失败！\n");
|
||||
printf("内存分配失败！\n");
|
||||
free(trips);
|
||||
return 1;
|
||||
}
|
||||
@ -82,12 +82,12 @@ int main() {
|
||||
int refuel_count = checkRefuelStops(trips, num_trips, results);
|
||||
|
||||
if (refuel_count > 0) {
|
||||
printf("【需要在以下几段赛程前充电：】\n");
|
||||
printf("【需要在以下几段赛程前充电：】\n");
|
||||
for (int i = 0; i < refuel_count; i++) {
|
||||
printf("第 %d 段赛程前\n", results[i]);
|
||||
printf("第 %d 段赛程前\n", results[i]);
|
||||
}
|
||||
} else {
|
||||
printf("无需充电。\n");
|
||||
printf("无需充电。\n");
|
||||
}
|
||||
|
||||
free(trips);
|
||||
|
||||
Loading…
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Reference in New Issue
Block a user