Ubuntu MariaDB查询语句怎么写

ubuntu

小樊

2025-10-06 03:19:26

栏目: 云计算

在Ubuntu上使用MariaDB时，编写查询语句的基本语法与其他关系型数据库（如MySQL）非常相似。以下是一些常见的查询语句示例：

SELECT * FROM table_name;

SELECT column1, column2 FROM table_name;

SELECT * FROM table_name WHERE condition;

例如，查询age大于30的记录：

SELECT * FROM users WHERE age > 30;

SELECT * FROM table_name ORDER BY column_name [ASC|DESC];

例如，按age降序排序：

SELECT * FROM users ORDER BY age DESC;

SELECT column1, COUNT(*) FROM table_name GROUP BY column1;

例如，按department分组并计算每个部门的员工数量：

SELECT department, COUNT(*) AS employee_count FROM employees GROUP BY department;

SELECT * FROM table1
UNION
SELECT * FROM table2;

例如，合并两个表中的记录：

SELECT name FROM users
UNION
SELECT username FROM customers;

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

例如，向users表插入一条记录：

INSERT INTO users (name, email) VALUES ('John Doe', 'john.doe@example.com');

UPDATE table_name SET column1 = value1 WHERE condition;

例如，更新users表中name为’John Doe’的记录：

UPDATE users SET email = 'john.newemail@example.com' WHERE name = 'John Doe';

DELETE FROM table_name WHERE condition;

例如，删除users表中name为’John Doe’的记录：

DELETE FROM users WHERE name = 'John Doe';

SELECT * FROM table1 WHERE column1 IN (SELECT column1 FROM table2);

例如，查询users表中department在departments表中的记录：

SELECT * FROM users WHERE department IN (SELECT department FROM departments);

希望这些示例对你有所帮助！如果有更多具体问题，请随时提问。

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