mysql 入库

-- 单条记录插入
INSERT INTO users (username, email, password) VALUES ('john_doe', 'john@example.com', 'secure_password');

-- 多条记录插入
INSERT INTO users (username, email, password) VALUES 
('jane_doe', 'jane@example.com', 'secure_password'),
('alex_smith', 'alex@example.com', 'secure_password');

-- 从其他表插入
INSERT INTO user_profiles (user_id, first_name, last_name)
SELECT id, 'John', 'Doe' FROM users WHERE username = 'john_doe';

-- 使用INSERT IGNORE
INSERT IGNORE INTO users (id, username, email) VALUES (1, 'john_doe', 'john@example.com');

-- 使用REPLACE INTO
REPLACE INTO users (id, username, email) VALUES (1, 'john_doe', 'john@example.com');

-- 先插入引用表中的数据
INSERT INTO departments (name) VALUES ('Engineering');

-- 再插入主表中的数据
INSERT INTO employees (name, department_id) VALUES ('John Doe', 1);

-- 使用CAST进行类型转换
INSERT INTO products (name, price) VALUES ('Laptop', CAST('999.99' AS DECIMAL(10, 2)));