JavaWeb_20231028

JavaWeb_20231028

Jakarta Standard Tag Library Tag Libraries

https://jakarta.ee/specifications/tags/3.0/jakarta-tags-spec-3.0#multiple-tag-libraries

<dependency>
  <groupId>jakarta.servlet.jsp.jstl</groupId>
  <artifactId>jakarta.servlet.jsp.jstl-api</artifactId>
  <version>3.0.0</version>
</dependency>
<dependency>
  <groupId>org.glassfish.web</groupId>
  <artifactId>jakarta.servlet.jsp.jstl</artifactId>
  <version>3.0.0</version>
</dependency>

建立訪客留言表(MySQL)

-- 刪除訪客留言表
drop table if exists guestbook;

-- 建立訪客留言表
create table if not exists guestbook(
	id int not null auto_increment,
    username varchar(50) not null,
    message varchar(255) not null,
    createtime timestamp default current_timestamp,
    primary key(id)
);

-- 建立訪客留言表預設資料
insert into guestbook(username, message) values('John', 'Hello 1');
insert into guestbook(username, message) values('Mary', 'Welcome 2');
insert into guestbook(username, message) values('海倫', '大家好 3');

-- 分頁 view
USE `demo`;
CREATE  OR REPLACE VIEW `guestbook_page_info` AS

select 10 as records_of_page, 
		count(*) as count, 
        ceil(count(*)/10) as max_page 
from guestbook;