USE day0321;
#创建作者表
CREATE TABLE IF NOT EXISTS author
(
id INT NOT NULL AUTO_INCREMENT,
author_name VARCHAR(50) DEFAULT NULL,
PRIMARY KEY(id)
);
SELECT * FROM author;
INSERT INTO author(author_name) VALUES
("张三"),
("namemman"),
('lucy'),
('lisi'),
('jack');
#创建博客表
CREATE TABLE IF NOT EXISTS blog
(
id INT PRIMARY KEY AUTO_INCREMENT,
title VARCHAR(50) DEFAULT NULL,
content VARCHAR(1000) DEFAULT NULL,
author_id INT DEFAULT NULL
);
INSERT INTO blog(title , content,author_id)VALUES
('测试博客01','测试博文01',1),
('测试博客02','测试博文02',2),
('测试博客03','测试博文03',3),
('测试博客04','测试博文04',4),
('测试博客05','测试博文05',5);
#创建视图:逻辑上的虚拟表
CREATE VIEW v_author (编号,姓名)
AS
SELECT * FROM author WITH CHECK OPTION;
#查询视图
SELECT * FROM v_author;
#创建多表视图
CREATE VIEW v_a_b(作者名字,博客标题,博客内容)
AS
SELECT a.author_name,b.title,b.content FROM author a LEFT JOIN blog b ON a.id=b.author_id;
#查询
SELECT * FROM v_a_b;
#修改视图
CREATE OR REPLACE VIEW v_blog(编号,标题,内容,作者编号)
AS SELECT * FROM blog
WITH CHECK OPTION;
#查询
SELECT * FROM v_blog;
#修改视图的数据
UPDATE v_blog SET 内容 = '修改后的内容' WHERE 编号 = '1';
#部分数据创建视图
CREATE VIEW v_blog_1(编号,标题,内容,作者编号)
AS SELECT * FROM blog WHERE author_id=1
WITH CHECK OPTION;
#查询
SELECT * FROM v_blog_1;
#with check option:where条件约束
INSERT INTO v_blog_1(编号,标题,内容,作者编号)VALUES(10,'123','123',1);