sql创建十个sql语句
时间: 2024-06-17 18:02:09 浏览: 7
当我们使用 SQL 时,最常见的任务之一就是创建数据库、表和视图,插入数据,更新数据,删除数据等。下面是十个 SQL 语句的示例:
1. 创建数据库:
CREATE DATABASE mydatabase;
2. 创建表:
CREATE TABLE customers (
customer_id INT PRIMARY KEY,
customer_name VARCHAR(50),
contact_name VARCHAR(50),
country VARCHAR(50)
);
3. 插入数据:
INSERT INTO customers (customer_id, customer_name, contact_name, country)
VALUES (1, 'CSDN', '张三', '中国');
4. 更新数据:
UPDATE customers
SET contact_name = '李四'
WHERE customer_id = 1;
5. 删除数据:
DELETE FROM customers
WHERE customer_id = 1;
6. 查询数据:
SELECT * FROM customers;
7. 排序数据:
SELECT * FROM customers
ORDER BY customer_name ASC;
8. 过滤数据:
SELECT * FROM customers
WHERE country = '中国';
9. 连接表:
SELECT *
FROM customers
INNER JOIN orders
ON customers.customer_id = orders.customer_id;
10. 创建视图:
CREATE VIEW china_customers AS
SELECT * FROM customers
WHERE country = '中国';