Mybatis基于注解开发和分页插件的用法，提供源码免费下载

mybatis_02.zip: https://url22.ctfile.com/f/38921122-910351821-9d66fe?p=3553 (访问密码: 3553)

基于注解基础操作

dao接口

package com.zhangdapeng520.mybatis.dao;

import com.zhangdapeng520.mybatis.entity.User;

import org.apache.ibatis.annotations.*;

import org.springframework.stereotype.Repository;

import java.util.List;

@Mapper

@Repository

public interface UserDao2 {

@Insert("insert into tb_user(name) values(#)")

void add(User user); // 添加

@Delete("delete from tb_user where id=#")

void delete(int id); // 删除

@Update("update tb_user set name=# where id=#")

void update(User user); // 更新

@Select("select id,name from tb_user where id=#")

User findById(int id); // 根据id查询

@Select("select id,name from tb_user")

List findAll(); // 查询所有

@Select("select id,name from tb_user limit # offset #")

List findPage(@Param("limit") int limit,

@Param("offset") int offset); // 分页查询

@Select("select count(*) from tb_user")

int count();// 查询总数

}

测试代码

package com.zhangdapeng520.mybatis;

import com.zhangdapeng520.mybatis.dao.UserDao;

import com.zhangdapeng520.mybatis.dao.UserDao2;

import com.zhangdapeng520.mybatis.entity.User;

import org.junit.jupiter.api.Test;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.boot.test.context.SpringBootTest;

import java.util.List;

@SpringBootTest

class UserDao2Tests {

@Autowired

private UserDao2 userDao2;

@Test

void testAdd() {

    User user = new User();

user.setName("张三");

userDao2.add(user);

}

@Test

void testFindById() {

User user = userDao2.findById(1);

System.out.println(user.getId());

System.out.println(user.getName());

}

@Test

void testUpdate() {

User user = new User();

user.setId(1);

user.setName("李四");

userDao2.update(user);

}

@Test

void testFindAll() {

List users = userDao2.findAll();

for (User user : users) {

System.out.println(user.getId()+"==="+user.getName());

}

}

@Test

void testFindPage() {

List users = userDao2.findPage(20,0);

for (User user : users) {

System.out.println(user.getId()+"==="+user.getName());

}

}

@Test

void testCount() {

int count = userDao2.count();

System.out.println(count);

}

@Test

void testDelete() {

userDao2.delete(1);

}

}

分页插件

引入依赖

com.github.pagehelper

pagehelper-spring-boot-starter

1.4.7

配置分页

pagehelper:

propertyName: propertyValue

reasonable: false

defaultCount: true # 分页插件默认参数支持 default-count 形式

测试方法

@Test

void testFindAll2() {

PageHelper.startPage(1, 10);

List users = userDao2.findAll();

for (User user : users) {

System.out.println(user.getId()+"==="+user.getName());

}

//用PageInfo对结果进行包装

PageInfo page = new PageInfo(users);

//测试PageInfo全部属性

//PageInfo包含了非常全面的分页属性

System.out.println(page.getPageNum());

System.out.println(page.getPageSize());

System.out.println(page.getStartRow());

System.out.println(page.getEndRow());

System.out.println(page.getTotal());

System.out.println(page.getPages());

System.out.println(page.isIsFirstPage());

System.out.println(page.isIsLastPage());

System.out.println(page.isHasPreviousPage());

System.out.println(page.isHasNextPage());

}