创建数据库YGGL、test和三张数据表的语句 2、按实训要求的其他语句

1. 创建数据库YGGL和test：

CREATE DATABASE YGGL;
CREATE DATABASE test;

2. 创建三张数据表：

CREATE TABLE employee (
id INT PRIMARY KEY,
name VARCHAR(50),
age INT,
department VARCHAR(50)
);

CREATE TABLE department (
id INT PRIMARY KEY,
name VARCHAR(50)
);

CREATE TABLE salary (
id INT PRIMARY KEY,
employee_id INT,
salary INT,
month VARCHAR(10),
FOREIGN KEY (employee_id) REFERENCES employee(id)
);

3. 其他语句：

- 插入数据：

INSERT INTO employee (id, name, age, department)
VALUES (1, '张三', 25, '销售部');

INSERT INTO department (id, name)
VALUES (1, '销售部');

INSERT INTO salary (id, employee_id, salary, month)
VALUES (1, 1, 5000, '2021-01');

- 查询数据：

SELECT * FROM employee;

SELECT * FROM department;

SELECT * FROM salary;

- 更新数据：

UPDATE employee SET age = 26 WHERE id = 1;

UPDATE salary SET salary = 5500 WHERE id = 1;

- 删除数据：

DELETE FROM employee WHERE id = 1;

DELETE FROM department WHERE id = 1;

DELETE FROM salary WHERE id = 1;