1，插入数据 (INSERT):
INSERT INTO table_name (column1, column2, column3, ...)
VALUES (value1, value2, value3, ...);
//示例：
INSERT INTO employees (name, age, department)
VALUES ('John Doe', 30, 'Sales');
2，查询数据 (SELECT):
SELECT column1, column2, ...
FROM table_name
WHERE condition;
//示例
SELECT * FROM employees;
或者
SELECT name, age FROM employees WHERE department='Sales';
3，更新数据 (UPDATE):
UPDATE table_name
SET column1 = value1, column2 = value2, ...
WHERE condition;
//示例
UPDATE employees
SET age = 31
WHERE name = 'John Doe';
4，删除数据 (DELETE):
DELETE FROM table_name
WHERE condition;
//示例
DELETE FROM employees WHERE name = 'John Doe';