Mybatis 学习之 分页实现

zxguan2024-09-29 23:40

文章目录

  • [1. Mybatis](#1. Mybatis)
    • [1.1. 代码实现](#1.1. 代码实现)
  • [2. Mybatis Plus](#2. Mybatis Plus)
    • [2.1. 代码实现](#2.1. 代码实现)
    • [2.2. 特别注意](#2.2. 特别注意)
  • [3. PageHelper](#3. PageHelper)
    • [3.1. 代码实现](#3.1. 代码实现)
    • [3.2. 特别注意](#3.2. 特别注意)
  • 参考资料

1. Mybatis

1.1. 代码实现

java 复制代码 
package com.example.demo;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@MapperScan(value = "com.example.demo.mapper")
@SpringBootApplication
public class DemoApplication {

	public static void main(String[] args) {
		SpringApplication.run(DemoApplication.class, args);
	}

}
java 复制代码 
package com.example.demo.mapper;

import com.example.demo.model.SysUser;
import com.example.demo.model.page.BasePageReq;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;

import java.util.List;

@Mapper
public interface UserMapper {

    List<SysUser> page(@Param(value = "pageReq") BasePageReq pageReq);

}
xml 复制代码 
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="com.example.demo.mapper.UserMapper">

    <select id="page" resultType="com.example.demo.model.SysUser">
        <bind name="startIndex" value="(pageReq.pageNum-1)*pageReq.pageSize"/>
        SELECT 
        	ID AS id, 
        	NAME AS name, 
        	AGE AS age
        FROM SYS_USER
        ORDER BY ID ASC
        LIMIT #{startIndex}, #{pageReq.pageSize}
    </select>

</mapper>
yml 复制代码 
mybatis:
  mapper-locations: classpath:mapper/*.xml
  type-aliases-package: com.example.demo.model
xml 复制代码 
<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
	<groupId>org.mybatis.spring.boot</groupId>
	<artifactId>mybatis-spring-boot-starter</artifactId>
	<version>2.3.0</version>
</dependency>

<dependency>
	<groupId>mysql</groupId>
	<artifactId>mysql-connector-java</artifactId>
	<version>8.0.15</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
<dependency>
	<groupId>org.projectlombok</groupId>
	<artifactId>lombok</artifactId>
	<version>1.18.24</version>
	<scope>provided</scope>
</dependency>
<dependency>
	<groupId>com.google.guava</groupId>
	<artifactId>guava</artifactId>
	<version>30.1-jre</version>
</dependency>

2. Mybatis Plus

2.1. 代码实现

java 复制代码 
package com.example.demo;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@MapperScan(value = "com.example.demo.mapper")
@SpringBootApplication
public class DemoApplication {

	public static void main(String[] args) {
		SpringApplication.run(DemoApplication.class, args);
	}

}
java 复制代码 
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;

Page<SysUser> list = userMapper.page(new Page<>(pageReq.getPageNum(), pageReq.getPageSize()));
java 复制代码 
package com.example.demo.mapper;

import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.example.demo.model.SysUser;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;

import java.util.List;

@Mapper
public interface UserMapper {

    Page<SysUser> page(@Param(value = "pageReq") IPage<SysUser> pageReq);

}
java 复制代码 
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="com.example.demo.mapper.UserMapper">

    <select id="page" resultType="com.example.demo.model.SysUser">
        SELECT ID AS id, NAME AS name, AGE AS age
        FROM SYS_USER
        ORDER BY ID ASC
    </select>

</mapper>
yml 复制代码 
mybatis-plus:
  mapper-locations: classpath*:mapper/*.xml
  type-aliases-package: com.example.demo.model
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
xml 复制代码 
<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
	<groupId>com.baomidou</groupId>
	<artifactId>mybatis-plus-boot-starter</artifactId>
	<version>3.5.1</version>
</dependency>
<dependency>
	<groupId>mysql</groupId>
	<artifactId>mysql-connector-java</artifactId>
	<version>8.0.15</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
<dependency>
	<groupId>org.projectlombok</groupId>
	<artifactId>lombok</artifactId>
	<version>1.18.24</version>
	<scope>provided</scope>
</dependency>
<dependency>
	<groupId>com.google.guava</groupId>
	<artifactId>guava</artifactId>
	<version>30.1-jre</version>
</dependency>

2.2. 特别注意

  • Mybatis Plus 分页功能中使用了 CCJSqlParser，其中 CCJSqlParser#Statement 在处理 复杂 SQL 时，存在 性能问题

3. PageHelper

3.1. 代码实现

java 复制代码 
package com.example.demo;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@MapperScan(value = "com.example.demo.mapper")
@SpringBootApplication
public class DemoApplication {

	public static void main(String[] args) {
		SpringApplication.run(DemoApplication.class, args);
	}

}
java 复制代码 
import com.github.pagehelper.Page;
import com.github.pagehelper.PageHelper;

Page<SysUser> list = PageHelper.startPage(pageReq.getPageNum(), pageReq.getPageSize()).doSelectPage(() -> userMapper.page());
java 复制代码 
package com.example.demo.mapper;

import com.example.demo.model.SysUser;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;

import java.util.List;

@Mapper
public interface UserMapper {

    List<SysUser> page();

}
xml 复制代码 
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="com.example.demo.mapper.UserMapper">

    <select id="page" resultType="com.example.demo.model.SysUser">
        SELECT ID AS id, NAME AS name, AGE AS age
        FROM SYS_USER
        ORDER BY ID ASC
    </select>

</mapper>
yml 复制代码 
mybatis-plus:
  mapper-locations: classpath*:mapper/*.xml
  type-aliases-package: com.example.demo.model
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
xml 复制代码 
<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
	<groupId>com.baomidou</groupId>
	<artifactId>mybatis-plus-boot-starter</artifactId>
	<version>3.5.1</version>
</dependency>
<dependency>
	<groupId>mysql</groupId>
	<artifactId>mysql-connector-java</artifactId>
	<version>8.0.15</version>
</dependency>
<!-- https://mvnrepository.com/artifact/com.github.pagehelper/pagehelper -->
<dependency>
	<groupId>com.github.pagehelper</groupId>
	<artifactId>pagehelper</artifactId>
	<version>5.0.0</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.projectlombok/lombok -->
<dependency>
	<groupId>org.projectlombok</groupId>
	<artifactId>lombok</artifactId>
	<version>1.18.24</version>
	<scope>provided</scope>
</dependency>
<dependency>
	<groupId>com.google.guava</groupId>
	<artifactId>guava</artifactId>
	<version>30.1-jre</version>
</dependency>

3.2. 特别注意

  • PageHelper 分页功能中使用了 CCJSqlParser，其中 CCJSqlParser#Statement 在处理 复杂 SQL 时，存在 性能问题

参考资料

相关推荐
序属秋秋秋42 分钟前
《C++初阶之内存管理》【内存分布 + operator new/delete + 定位new】
开发语言·c++·笔记·学习
许白掰1 小时前
Linux入门篇学习——Linux 工具之 make 工具和 makefile 文件
linux·运维·服务器·前端·学习·编辑器
B1nna2 小时前
Docker学习
学习·docker·容器
promising-w8 小时前
【运算放大器专题】基础篇
嵌入式硬件·学习
宝山哥哥8 小时前
网络信息安全学习笔记1----------网络信息安全概述
网络·笔记·学习·安全·网络安全
前端开发与ui设计的老司机8 小时前
从UI设计到数字孪生实战：构建智慧教育的个性化学习平台
学习·ui
X Y O8 小时前
神经网络初步学习3——数据与损失
人工智能·神经网络·学习
霖0010 小时前
C++学习笔记三
运维·开发语言·c++·笔记·学习·fpga开发
巴伦是只猫11 小时前
【机器学习笔记 Ⅲ】1 无监督学习
笔记·学习·机器学习
武昌库里写JAVA12 小时前
vue3面试题(个人笔记)
java·vue.js·spring boot·学习·课程设计
热门推荐
01KGG转MP3工具|非KGM文件|解密音频02集群聊天服务器---MySQL数据库的建立03Coze扣子平台完整体验和实践（附国内和国际版对比）04Ubuntu环境下统计进程资源利用率05使用Ruby接入实时行情API教程06扣子（coze）实战|我用扣子搭建了一个自动分析小红薯笔记内容的AI应用|详细步骤拆解07深度神经网络训练过程与常见概念08Java学习第十五部分——MyBatis09DeepSeek各版本说明与优缺点分析10浅谈几种js设计模式