MySQL的增删改查代码

以下是MySQL的增删改查代码示例：

1. 插入数据

INSERT INTO table_name (column1, column2, column3, ...)
VALUES (value1, value2, value3, ...);

2. 更新数据

UPDATE table_name
SET column1 = value1, column2 = value2, ...
WHERE condition;

3. 删除数据

DELETE FROM table_name WHERE condition;

4. 查询数据

SELECT column1, column2, ...
FROM table_name
WHERE condition
ORDER BY column_name ASC|DESC
LIMIT count OFFSET num;

其中，`table_name`是要操作的表名，`column1, column2, ...`为表中的列名，`value1, value2, ...`为要插入的值，`condition`为查询条件，`column_name`为排序的列名，`count`为要查询的行数，`num`为偏移量。

例如，插入一条数据：

INSERT INTO students (name, age, gender) VALUES ('Tom', 18, 'male');

更新一条数据：

UPDATE students SET age = 20 WHERE name = 'Tom';

删除一条数据：

DELETE FROM students WHERE name = 'Tom';

查询所有学生的姓名和年龄：

SELECT name, age FROM students;

查询年龄大于等于18岁的学生：

SELECT * FROM students WHERE age >= 18;

按年龄升序排序并限制返回两条数据：

SELECT * FROM students ORDER BY age ASC LIMIT 2;