mysql怎么创建分表

CREATE TABLE user_info (
    id INT PRIMARY KEY,
    username VARCHAR(50),
    email VARCHAR(100),
    address TEXT,
    phone VARCHAR(20)
);

CREATE TABLE user_contact (
    id INT PRIMARY KEY,
    user_id INT,
    address TEXT,
    phone VARCHAR(20),
    FOREIGN KEY (user_id) REFERENCES user_info(id)
);

ALTER TABLE user_info DROP COLUMN address, DROP COLUMN phone;

CREATE TABLE orders (
    id INT PRIMARY KEY,
    user_id INT,
    order_date DATE,
    total_amount DECIMAL(10, 2)
);

CREATE TABLE orders_0 (
    id INT PRIMARY KEY,
    user_id INT,
    order_date DATE,
    total_amount DECIMAL(10, 2)
);

CREATE TABLE orders_1 (
    id INT PRIMARY KEY,
    user_id INT,
    order_date DATE,
    total_amount DECIMAL(10, 2)
);

DELIMITER $$
CREATE FUNCTION get_order_table(user_id INT) RETURNS VARCHAR(20)
BEGIN
    DECLARE table_name VARCHAR(20);
    SET table_name = CONCAT('orders_', user_id % 2);
    RETURN table_name;
END$$
DELIMITER ;

INSERT INTO (SELECT get_order_table(user_id)) (id, user_id, order_date, total_amount)
VALUES (1, 101, '2023-04-01', 150.00);

SELECT * FROM user_info ui
JOIN (SELECT * FROM orders_0 UNION ALL SELECT * FROM orders_1) o ON ui.id = o.user_id;