mysql 值域约束

DELIMITER $$
CREATE TRIGGER check_salary_before_insert
BEFORE INSERT ON employees
FOR EACH ROW
BEGIN
    IF NEW.salary < 0 THEN
        SIGNAL SQLSTATE '45000'
        SET MESSAGE_TEXT = 'Salary cannot be negative';
    END IF;
END$$
DELIMITER ;

CREATE TABLE employees (
    id INT PRIMARY KEY,
    name VARCHAR(100),
    department_id INT,
    FOREIGN KEY (department_id) REFERENCES departments(id)
);

CREATE TABLE users (
    id INT PRIMARY KEY,
    username VARCHAR(50) UNIQUE
);

CREATE TABLE users (
    id INT PRIMARY KEY,
    username VARCHAR(50) NOT NULL
);

DELIMITER $$
CREATE TRIGGER check_age_before_insert
BEFORE INSERT ON users
FOR EACH ROW
BEGIN
    IF NEW.age < 0 OR NEW.age > 120 THEN
        SIGNAL SQLSTATE '45000'
        SET MESSAGE_TEXT = 'Age must be between 0 and 120';
    END IF;
END$$
DELIMITER ;

try:
    cursor.execute("INSERT INTO users (username, age) VALUES (%s, %s)", ('user1', -5))
    connection.commit()
except mysql.connector.IntegrityError as err:
    print(f"Error: {err}")
    connection.rollback()