MySQL视图中用变量实现自动加入序号功能

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

SELECT 
    (@row_number := @row_number + 1) AS row_num, 
    t.id, 
    t.name, 
    t.age
FROM 
    (SELECT @row_number := 0) r,
    your_table t
ORDER BY 
    t.id;

CREATE VIEW your_view AS
SELECT 
    (@row_number := @row_number + 1) AS row_num, 
    t.id, 
    t.name, 
    t.age
FROM 
    (SELECT @row_number := 0) r,
    your_table t
ORDER BY 
    t.id;

CREATE VIEW your_view AS
SELECT 
    ROW_NUMBER() OVER (ORDER BY id) AS row_num, 
    id, 
    name, 
    age
FROM 
    your_table;

INSERT INTO your_table (id, name, age) VALUES
(1, 'Alice', 30),
(2, 'Bob', 25),
(3, 'Charlie', 35);

SELECT * FROM your_view;

+---------+----+--------+-----+
| row_num | id | name   | age |
+---------+----+--------+-----+
|       1 |  1 | Alice  |  30 |
|       2 |  2 | Bob    |  25 |
|       3 |  3 | Charlie|  35 |
+---------+----+--------+-----+